html before text

DIAGNOSTIC/TROUBLESHOOTING MANUAL
DIAGNOSTIC/TROUBLESHOOTING MANUAL
MaxxForce® 15 Engine Diagnostic Manual
Engine Family: MaxxForce® 15
EGES-515-1
2012
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.


DIAGNOSTIC/TROUBLESHOOTING MANUAL
I
Table of Contents
Foreword
1
Service Diagnosis
2
Safety Information
3
Engine Systems
5
Engine and Vehicle Features
51
Diagnostic Software Operation
59
Engine Symptoms Diagnostics
67
Hard Start and No Start Diagnostics
101
Performance Diagnostics
135
Electronic Control Systems Diagnostics
171
Diagnostic Tools and Accessories
375
Abbreviations and Acronyms
401
Terminology
409
Appendix A: Performance Specifications
421
Appendix B: Signal Values
433
Appendix C: Technical Service Information (TSI)
443
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

II
DIAGNOSTIC/TROUBLESHOOTING MANUAL
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

DIAGNOSTIC/TROUBLESHOOTING MANUAL
1
Foreword
Technical Service Literature
Navistar, Inc. is committed to continuous research
1172042R1
MaxxForce® 15 Engine Operation
and development to improve products and introduce
and Maintenance Manual
technological advances. Procedures, specifications,
EGES-510-2
MaxxForce® 15 Engine Service
and parts defined in published technical service
Manual
literature may be altered.
EGES-515-1
MaxxForce® 15 Engine Diagnostic
NOTE: Photo illustrations identify specific parts or
manual
assemblies that support text and procedures; other
EGED-520-1
MaxxForce® 15 Hard Start and
areas in a photo illustration may not be exact.
No Start Diagnostics Form
This manual includes necessary information and
EGED-535-1
MaxxForce® 15 Performance
specifications for technicians to maintain Navistar®
Diagnostics Form
diesel engines. See vehicle manuals and Technical
Service Information
(TSI) bulletins for additional
EGED-525-1
MaxxForce® 15 Engine Wiring
information.
Diagram Form
Technical Service Literature is revised periodically
and mailed automatically to
“Revision Service”
subscribers. If a technical publication is ordered, the
latest revision will be supplied.
NOTE: To order technical service literature, contact
your International dealer.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

2
DIAGNOSTIC/TROUBLESHOOTING MANUAL
Service Diagnosis
•
Knowledge of the principles of operation for
engine application and engine systems
Service diagnosis is an investigative procedure that
must be followed to find and correct an engine
•
Knowledge to understand and do procedures in
application problem or an engine problem.
diagnostic and service publications
If the problem is engine application, see specific
Technical Service Literature required for Effective
vehicle manuals for further diagnostic information.
Diagnosis
If the problem is the engine, see specific Engine
•
Engine Service Manual
Diagnostic Manual for further diagnostic information.
•
Engine Diagnostic Manual
Prerequisites for Effective Diagnosis
•
Diagnostics Forms
•
Availability of gauges and diagnostic test
•
Electronic Control Systems Diagnostics Forms
equipment
•
Service Bulletins
•
Availability of current information for engine
application and engine systems
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

DIAGNOSTIC/TROUBLESHOOTING MANUAL
3
Safety Information
•
Restrain long hair.
Vehicle
This manual provides general and specific
maintenance procedures essential for reliable engine
•
Make sure the vehicle is in neutral, the parking
operation and your safety. Since many variations in
brake is set, and the wheels are blocked before
procedures, tools, and service parts are involved,
servicing engine.
advice for all possible safety conditions and hazards
•
Clear the area before starting the engine.
cannot be stated.
Engine
Read safety instructions before doing any service and
test procedures for the engine or vehicle. See related
•
The engine should be operated or serviced only
application manuals for more information.
by qualified individuals.
Disregard for Safety Instructions, Warnings, Cautions,
•
Provide necessary ventilation when operating
and Notes in this manual can lead to injury, death or
engine in a closed area.
damage to the engine or vehicle.
•
Keep combustible material away from engine
exhaust system and exhaust manifolds.
Safety Terminology
•
Install all shields, guards, and access covers
Three terms are used to stress your safety and safe
before operating engine.
operation of the engine: Warning, Caution, and Note
•
Do not run engine with unprotected air inlets or
Warning: A warning describes actions necessary to
exhaust openings. If unavoidable for service
prevent or eliminate conditions, hazards, and unsafe
reasons, put protective screens over all openings
practices that can cause personal injury or death.
before servicing engine.
Caution: A caution describes actions necessary
•
Shut engine off and relieve all pressure in the
to prevent or eliminate conditions that can cause
system before removing panels, housing covers,
damage to the engine or vehicle.
and caps.
Note: A note describes actions necessary for correct,
•
If an engine is not safe to operate, tag the engine
efficient engine operation.
and ignition key.
Safety Instructions
Fire Prevention
Work Area
•
Make sure charged fire extinguishers are in the
work area.
•
Keep work area clean, dry, and organized.
NOTE: Check the classification of each fire
•
Keep tools and parts off the floor.
extinguisher to ensure that the following fire types
•
Make sure the work area is ventilated and well lit.
can be extinguished.
•
Make sure a First Aid Kit is available.
1. Type A — Wood, paper, textiles, and rubbish
Safety Equipment
2. Type B — Flammable liquids
•
Use correct lifting devices.
3. Type C — Electrical equipment
•
Use safety blocks and stands.
Batteries
Protective Measures
•
Always disconnect the main negative battery
cable first.
•
Wear protective safety glasses and shoes.
•
Always connect the main negative battery cable
•
Wear correct hearing protection.
last.
•
Wear cotton work clothing.
•
Avoid leaning over batteries.
•
Wear sleeved heat protective gloves.
•
Protect your eyes.
•
Do not wear rings, watches or other jewelry.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

4
DIAGNOSTIC/TROUBLESHOOTING MANUAL
•
Do not expose batteries to open flames or sparks.
•
Check for frayed power cords before using power
tools.
•
Do not smoke in workplace.
Fluids Under Pressure
Compressed Air
•
Use extreme caution when working on systems
•
Use an OSHA approved blow gun rated at 207
under pressure.
kPa (30 psi).
•
Follow approved procedures only.
•
Limit shop air pressure to 207 kPa (30 psi).
Fuel
•
Wear safety glasses or goggles.
•
Do not over fill the fuel tank. Over fill creates a fire
•
Wear hearing protection.
hazard.
•
Use shielding to protect others in the work area.
•
Do not smoke in the work area.
•
Do not direct compressed air at body or clothing.
•
Do not refuel the tank when the engine is running.
Tools
Removal of Tools, Parts, and Equipment
•
Make sure all tools are in good condition.
•
Reinstall all safety guards, shields, and covers
•
Make sure all standard electrical tools are
after servicing the engine.
grounded.
•
Make sure all tools, parts, and service equipment
are removed from the engine and vehicle after all
work is done.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
5
Table of Contents
Engine Identification
7
Engine Serial Number
7
Engine Emission Label
7
Engine Accessory Labels and Identification Plates
8
Engine Specifications
9
Engine Description
9
Optional Features
10
Chassis Mounted Features
10
Engine Component Locations
11
Air Management System (AMS)
16
Air Flow
16
Air Management Components
17
Turbochargers
17
Interstage Cooler (ISC)
18
High-Pressure Charge Air Cooler (HPCAC)
19
Air Control Valve
19
Exhaust Gas Recirculation (EGR) System
20
Aftertreatment (AFT) System
22
Aftertreatment Fuel Injection Components
24
Fuel Management System
26
Chassis Mounted Components
27
Engine Mounted Components
29
Engine Lubrication System
31
Oil Flow and Components
32
Engine Cooling System
34
Cooling System Components
34
Cooling System Flow
35
Thermostat Operation
36
Coolant Control Valve (CCV) Assembly Operation
36
MaxxForce®Engine Brake System
38
Engine Brake System Components
38
Engine Brake Operation
39
Open Crankcase Breather System
40
Open Crankcase Breather System Components
40
Open Crankcase Breather System Operation
41
Cold Start Assist System
42
Cold Start Assist System Operation
43
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

6
1 ENGINE SYSTEMS
Electronic Control System
44
Electronic Control System Components
44
Operation and Function
44
Reference Voltage (VREF)
44
Signal Conditioner
44
Microprocessor
44
Diagnostic Trouble Codes
44
Microprocessor Memory
44
Actuator Control
45
Actuators
45
Coolant Flow Valve and Coolant Mixer Valve
45
Exhaust Gas Recirculation (EGR) Valve Assembly
45
Air Control Valve
45
Cold Start Relay (CSR)
45
Cold Start Fuel Solenoid (CSFS)
45
Engine Throttle Valve (ETV)
46
Fuel Pressure Control Valve (FPCV)
46
Engine and Vehicle Sensors
46
Thermistor Sensor
46
Variable Resistance Sensor
47
Magnetic Pickup Sensor
48
Potentiometer
49
Switches
49
Oxygen Sensor (O2S)
50
Turbocharger 2 Compressor Inlet Sensor (TC2CIS)
50
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
7
Engine Identification
Engine Emission Label
Engine Serial Number
Figure 1
Engine serial number location
The engine serial number is located on the lower left
side of the crankcase above the oil pan flange.
Engine Serial Number Example
Figure 2
U.S. Environmental Protection Agency
(EPA) exhaust emission label (example)
152HM2YXXXXXXX
Engine Serial Number Codes
The U.S. Environmental Protection Agency (EPA)
15.2 – Engine displacement
exhaust emission label is on top of the valve cover
H – Diesel, turbocharged, Charge Air Cooler (CAC)
(front left side). The EPA label typically includes the
and electronically controlled
following:
M2 – Motor truck
•
Model year
Y – United States, Huntsville
7 digit suffix – Engine serial number sequence
•
Engine family, model, and displacement
•
Advertised brake horsepower and torque rating
•
Emission family and control systems
•
Valve lash specifications
•
Engine serial number
•
EPA, EURO, OBD and reserved fields for specific
applications
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

8
1 ENGINE SYSTEMS
Engine Accessory Labels and Identification Plates
•
Cooling fan clutch
The following engine accessories may have
•
High-pressure fuel pump
manufacturer’s labels or identification plates:
•
Power steering pump
•
Air compressor
•
Starter motor
•
Air conditioning compressor
•
Turbochargers
•
Alternator
•
Engine Control Module (ECM)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
9
Engine Specifications
MaxxForce® 15 Diesel Engine
Engine Configuration
4 stroke, inline six cylinder diesel
Advertised brake horsepower @ rpm
See EPA exhaust emission label
Peak torque @ rpm
See EPA exhaust emission label
Displacement
15.2 L (928 in3)
Compression ratio
16.0:1
Stroke
171.5 mm (6.75 in)
Bore (sleeve diameter)
137.2 mm (5.40 in)
Engine weight (dry, without trim or accessories)
1 429 kg (3,150 lbs)
Firing order
1-5-3-6-2-4
Engine rotation (facing flywheel)
Counterclockwise
Aspiration
Dual turbocharged and Charge Air
Cooled (CAC)
Combustion system
Direct injection turbocharged
Fuel system
High-pressure common rail
Lube system refill capacity (including filter)
•
Gravity drain from right rear and bottom front sump plugs
38 L (40 qts)
•
Suction oil recovery option
34.5 L (36.5 qts)
Engine lubrication oil pressure at 99°C (210°F)
•
600 rpm
Minimum 83 kPa (12 psi)
•
1,600 rpm
275 – 550 kPa (40 – 80 psi)
Idle speed (no load)
600 rpm, nominal
Thermostat transition range (start open — full open)
88°C – 103°C (190°F – 217°F)
Engine Description
The MaxxForce® 15 engine uses one piece forged
steel pistons. Cooling jet cutouts and feed holes are
The MaxxForce® 15 diesel engine has been designed
placed on both sides of the pistons. Pistons may
for increased durability and reliability.
be installed in either direction however pistons are
The cylinder head has four valves per cylinder with
originally installed with casting bump on bottom of pin
centrally located fuel injectors directing fuel over
boss toward rear of engine.
the pistons. This configuration provides improved
The one piece crankcase can withstand high-pressure
performance and reduces emissions.
loads during operation.
The crankcase uses
The overhead camshaft is supported by seven
replaceable wet cylinder sleeves that are sealed
bearings in the cylinder head. The camshaft gear is
by a system of three O-rings.
driven from the front of the engine. The overhead
Sound shields are strategically placed on the engine
valve train includes roller rocker arms and dual valves
to reduce noise.
that open using a valve bridge.
The crankshaft has seven main bearings with fore
and aft thrust controlled at the forth bearing. One
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

10
1 ENGINE SYSTEMS
connecting rod is attached at each crankshaft journal.
The engine brake is standard on the MaxxForce® 15.
The piston pin moves freely inside the connecting rod
The engine brake is a compression release system
and piston. Piston pin retaining rings secure the piston
that provides additional vehicle braking performance.
pin in the piston. The rear oil seal carrier is part of the
The operator can control the engine brake for different
flywheel housing, and the front oil seal carrier is part
operating conditions.
of the front cover.
An oil pump is mounted within the oil pan to the
Optional Features
bottom of the crankcase behind the front cover and is
driven by the crankshaft. Pressurized oil is supplied to
An oil pan heater and a coolant heater are available
internal engine components, air compressor, power
as optional cold climate features. Both heaters use an
steering pump and turbochargers. All MaxxForce®
electric element to warm engine fluids in cold weather
15 engines use an engine oil cooler and a spin-on
conditions.
can style engine oil filter element.
The oil pan heater warms engine oil to ensure
Fuel is drawn from the fuel tank through the
optimum oil flow to engine components.
frame-mounted fuel/water filter separator. A hand
The coolant heater warms the engine coolant
operated primer pump is located either on top of
surrounding the cylinders. Warmed engine coolant
or next to the frame-mounted fuel/water separator.
increases fuel economy and aids start-up in cold
The fuel is then routed into the fuel pump and to the
weather conditions.
engine-mounted fuel filter. Conditioned fuel is then
pumped to the fuel injectors.
The fuel injection system is direct common rail. The
Chassis Mounted Features
system includes a high-pressure fuel pump, fuel rail
The aftertreatment system, part of the larger
and fuel injectors. The injectors are installed in the
exhaust system, processes engine exhaust so that
cylinder head under the valve cover.
it meets tailpipe emission requirements. Most of the
The MaxxForce® 15 engine uses dual turbochargers
aftertreatment system is mounted on the chassis.
with an air-to-liquid Interstage Cooler (ISC) between
•
The Pre-Diesel Oxidation Catalyst
(PDOC)
turbochargers, and a chassis-mounted air-to-air
and Diesel Oxidation Catalyst (DOC) which is
Charge Air Cooler (CAC) to reduce air temperature
mounted on the chassis, oxidizes hydrocarbons
before entering the intake.
and carbon monoxide, provides heat for exhaust
The cold start assist system warms the incoming
system warm-up, and aids in temperature
air supply before, during, and a short period after
management for the Diesel Particulate Filter
cranking to aid cold engine starting and reduce white
(DPF) for passive DPF regeneration.
smoke during warm-up.
•
The DPF temporarily stores carbon-based
The Exhaust Gas Recirculation
(EGR) system
particulates then oxidizes the particulates and
circulates cooled exhaust into the intake air stream in
stores the noncombustible ash.
the mixing duct. This cools the combustion process
The High-Pressure Charge Air Cooler
(HPCAC)
and reduces the formation of Nitrogen Oxides (NOX)
mounted on the vehicle cooling module, is connected
engine emissions. The EGR cooler assembly cools
between the outlet of the high-pressure turbocharger
the exhaust gas in two stages.
and the inlet to the engine throttle valve assembly.
An open crankcase breather system uses an oil
The HPCAC is an air-to-air cooler that uses ambient
separator to return oil to the crankcase and vent
air to cool pressurized air before it enters the engine.
the crankcase gasses to the atmosphere. The oil
separator is mounted on the cylinder head.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
11
Engine Component Locations
Figure 3
Component location – top
1.
Turbocharger interstage cooler
3.
Valve cover assembly
6.
Charge Air Cooler Outlet
assembly
4.
Exhaust gas temperature sensor
Temperature (CACOT) sensor
2.
Flywheel housing assembly
5.
Cold Start Fuel Igniter (CSFI)
7.
Breather filter assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

12
1 ENGINE SYSTEMS
Figure 4
Component location – front
1.
Water pump pulley
4.
EGR crossover tube assembly
7.
Camshaft gear cover
2.
Air inlet duct (turbocharger)
5.
Engine throttle valve assembly
8.
Low mount fan drive
3.
Front lifting eye
6.
Oil filler pipe assembly
9.
Damper (crankshaft)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
13
Figure 5
Component location – right
1.
Pre-Diesel Oxidation Catalyst
6.
Interstage cooler assembly
11. Oil filter
(PDOC) assembly
7.
High-pressure turbocharger
12. Low-Pressure (LP) turbocharger
2.
Fuel doser
compressor outlet
assembly
3.
Exhaust Gas Recirculation
8.
Oil supply tube for secondary
13. High-pressure turbocharger
(EGR) cooler assembly
filtration (to soot filter)
wastegate actuator
4.
High-Pressure (HP)
9.
Coolant inlet (from radiator)
14. Engine oil cooler assembly
turbocharger assembly
10. Coolant Control Valve (CCV)
5.
Thermostat housing
assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

14
1 ENGINE SYSTEMS
Figure 6
Component location – left
1.
Air compressor
7.
Fuel Delivery Pressure (FDP)
12. Oil pan drain plug (front sump)
2.
Oil level gauge assembly
sensor
13. Cold Start Fuel Solenoid (CSFS)
3.
Crankcase breather
8.
Fuel filter
14.
5 mm 60 degree speed sensor
4.
Engine Control Module (ECM)
9.
Oil pan drain plug (rear sump)
(crankshaft position sensor)
5.
Down Stream Injection (DSI)
10. Crankcase Pressure (CPS)
15. High-pressure fuel pump
assembly
sensor
16. Power steering pump
6.
12V relay (for cold start assist
11. Engine Oil Pressure (EOP)
solenoid)
sensor
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
15
Figure 7
Component location – rear
1.
Rear lifting eye
3.
Fuel return tube assembly
6.
Oil pan
2.
Exhaust Gas Recirculation
4.
EGR cooler supply tube
7.
Flywheel housing
(EGR) valve assembly
5.
Flywheel
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

16
1 ENGINE SYSTEMS
Air Management System (AMS)
Figure 8
Air Management System (AMS)
Air Flow
air flows into the Charge Air Cooler (CAC) where it
is cooled, and then directed to the Engine Throttle
Air flows through the air cleaner assembly and enters
Valve (ETV) and mixing duct area of the throttle valve
the low-pressure turbocharger. The low-pressure
assembly.
turbocharger increases the pressure, temperature,
and density of the intake air before it enters the
If the EGR control valve is open, exhaust gas passes
Interstage Cooler (ISC). Cooled compressed air flows
through the EGR system into the mixing duct where it
from the ISC into the high-pressure turbocharger. The
is mixed with the filtered intake air. This mixture flows
high-pressure turbocharger increases the intake air
through the mixing duct into the intake manifold and
pressure up to 345 kPa (50 psi). The hot compressed
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
17
cylinder head. The intake manifold is an integral part
Air Management Components
of the cylinder head casting.
Turbochargers
If the EGR control valve is closed, only filtered intake
The MaxxForce® 15 engine is equipped with an
air flows through the ETV, mixing duct, and into the
electronically controlled, pneumatically actuated two
intake manifold.
stage turbocharging system. This system provides
During cold weather, the Cold Start Fuel Igniter (CSFI)
high levels of charge air pressure to improve engine
rapidly heats the intake air by injecting and igniting
performance and help reduce emissions. Because of
small quantities of fuel into the mixing duct.
its ability to generate very high charge air pressure
levels, the system is fitted with an air control valve
After combustion, gases exit through the cylinder
to control over-boost and surging conditions. The
head exhaust valves and ports. The exhaust gas
air control valve is supplied compressed air from the
is forced through the exhaust manifold where,
vehicle air supply tank. The compressed air flow to
depending on the EGR valve assembly position,
the wastegate actuator is electronically controlled
is split between the EGR system and the exit
by the air control valve based on the Pulse Width
path through the high-pressure turbocharger and
Modulated
(PWM) signal supplied by the Engine
low-pressure turbocharger.
Control Module (ECM). The high and low-pressure
The exhaust gases flow from the low-pressure
turbochargers are installed as an assembly on the
turbocharger through the vehicle aftertreatment
exhaust manifold, on the right side of the engine.
system to the exhaust tail pipe.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

18
1 ENGINE SYSTEMS
Figure 9
Low and high-pressure turbocharger components
1.
Low-pressure turbocharger
6.
High-pressure turbocharger
11. High-pressure turbocharger
assembly
turbine inlet
compressor outlet
2.
High-pressure turbocharger oil
7.
Low-pressure turbocharger
12. High-pressure turbocharger
supply hose
assembly
wastegate actuator
3.
Air control valve
8.
Low-pressure turbocharger oil
13. Turbine output pressure tube
4.
High-pressure turbocharger
supply hose
14. Turbocharger oil drain tube
assembly
9.
Low-pressure turbocharger
assembly
5.
High-pressure turbocharger
compressor outlet
15. Low-pressure turbocharger
compressor inlet
10. Low-pressure turbocharger
turbine outlet
compressor inlet
The low and high-pressure turbochargers are installed
Fresh air from the air filter enters the low-pressure
in series on the right side of the engine. The
compressor where it is compressed and directed into
high-pressure turbocharger is connected directly
the Interstage Cooler (ISC). Cooled condensed air
to the exhaust manifold through the high-pressure
from the ISC enters the high-pressure compressor,
turbine inlet. The turbine input of the low-pressure
where it is further compressed and directed to the
turbocharger is connected to the turbine outlet of
High-Pressure Charge Air Cooler (HPCAC) mounted
the high-pressure turbocharger. The high-pressure
near the cooling module. Cooled and condensed air
turbocharger is equipped with a wastegate actuator
then flows directly into the engine throttle valve.
which regulates turbocharger boost by controlling
the amount of exhaust gases that pass through the
turbine. When boost demand is low, the wastegate
Interstage Cooler (ISC)
opens, allowing part of the exhaust gas flow to bypass
The ISC is installed between the low-pressure and
the turbine.
the high-pressure turbochargers. The ISC air inlet
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
19
is connected to the low-pressure compressor outlet
The air control valve controls air pressure to the
and uses engine coolant to regulate the charge air
high-pressure wastegate actuator based on turbine
temperature. The ISC air outlet is connected to the
output pressure from a port on the output of the
compressor inlet on the high-pressure turbocharger.
low-pressure turbocharger.
The turbine output
pressure sensor is integral to the air control valve. Air
pressure to the air control valve is supplied from an
High-Pressure Charge Air Cooler (HPCAC)
air tank mounted on the chassis. The air control valve
is controlled by the Engine Control Module (ECM).
The HPCAC is installed between the high-pressure
turbocharger compressor outlet and the Engine
The air control valve is normally closed. Thus, with no
Throttle Valve (ETV). The HPCAC uses ambient air
Pulse Width Modulated (PWM) signal, the air control
flow to regulate the charge air temperature. The
valve remains closed and no air pressure is supplied
HPCAC air outlet is connected to the ETV body.
to the wastegate actuator on the high-pressure
turbocharger.
When a decrease in charge air
pressure is required, the ECM supplies a PWM
Air Control Valve
ground voltage to the negative side of the wastegate
control solenoid. The other side of the wastegate
control solenoid is connected to 12V supply voltage.
This causes the air control valve to open which
supplies air pressure to the wastegate actuator.
The limit values of the PWM signal are between
approximately 95%, corresponding to an open air
control valve, and 5%, corresponding to a closed air
control valve. When the air control valve closes, it
interrupts the air supply to the wastegate actuator
and at the same time relieves air pressure from the
wastegate by allowing it to vent to atmosphere. The
wastegate actuator then closes, resulting in increased
charge air pressure.
Figure 10
Air control valve
1.
To high-pressure turbocharger wastegate actuator
2.
Turbocharger 1 Turbine Output Pressure (TC1TOP)
input to sensor
3.
Compressed regulated air supply from chassis air
tank
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

20
1 ENGINE SYSTEMS
Exhaust Gas Recirculation (EGR) System
Figure 11
EGR system
1.
EGR valve assembly
5.
EGR cooler assembly
8.
EGRV coolant supply tube
2.
EGR coolant tube assembly
6.
EGRV coolant return tube
assembly
3.
EGR crossover tube assembly
assembly
4.
EGR coolant tube assembly
7.
EGR cooler supply tube
EGR System Overview
Control Module
(ECM) to control the EGR valve
assembly.
The EGR system reduces Nitrogen Oxides (NOX)
engine emissions by introducing cooled exhaust gas
The EGR system consists of an EGR valve, EGR
into the mixing duct. NOX forms during a reaction
cooler assembly and an O2S
. The EGR valve
between nitrogen and oxygen at high temperatures
assembly is mounted on the rear of the EGR cooler
during combustion. An Oxygen Sensor (O2S) located
assembly.
in the turbo exhaust duct, monitors the oxygen content
The EGR cooler assembly is located on the right side
in the exhaust gas and provides input to the Engine
of the valve cover above the exhaust manifold.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
21
EGR Flow
aftertreatment fuel injector. The O2S has a heater
element that heats the sensor to its normal operating
Exhaust gas from the exhaust manifold flows through
temperature of 780°C (1,436°F). During initial engine
the EGR cooler supply tube to the EGR valve
warm-up, the O2S heater element is activated only
assembly. When the EGR is activated, the EGR
after the engine coolant reaches 40°C (104°F) and
valve assembly opens and allows exhaust gas to
the exhaust gas temperature exceeds 100°C (212°F)
enter the EGR cooler assembly for cooling. Cooled
for more than 30 seconds.
exhaust gas flows from the EGR cooler assembly into
the mixing duct where it is mixed with filtered intake
EGR Open Loop System
air.
During the engine warm-up period and before the
EGR Control
Oxygen Sensor (O2S) reaches its normal operating
temperature, the EGR system operates in open
The ECM monitors signals from the Intake Manifold
loop. In open loop, the EGR system is controlled
Temperature
(IMT) sensor and Engine Coolant
by the ECM based on the charge air temperature,
Temperature
(ECT) sensor to control the EGR
engine coolant temperature, engine speed, and load
system. The EGR is switched off
(EGR valve
conditions. The EGR actuator provides feedback to
assembly closed) if any of the following conditions
the ECM on current valve position through the EGRP
are present:
sensor.
•
Charge air temperature is low
EGR Closed Loop System
•
Intake manifold temperature is low
After the Oxygen Sensor (O2S) reaches its operating
•
Engine coolant temperature is low
temperature, the EGR system switches to closed
•
During engine brake operation
loop operation. In closed loop, the EGR system is
controlled by the ECM based on the O2S readings.
•
When Cold Ambient Protection (CAP) mode is
active
The Oxygen Sensor
(O2S) is installed in the
turbocharger exhaust duct, in front of the
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

22
1 ENGINE SYSTEMS
Aftertreatment (AFT) System
Figure 12
AFT system overview
The Aftertreatment (AFT) System, part of the larger
The sensors measure O2, temperature and pressure
exhaust system, processes engine exhaust to meet
at the center of the exhaust flow.
emissions requirements. The AFT system traps
particulate matter (soot) and prevents it from leaving
Down Stream Injection (DSI)
the tailpipe.
The aftertreatment system injects fuel through the
The AFT system performs the following functions:
fuel doser into the exhaust gas to increase the
temperature necessary for DPF regeneration. The
•
Monitors exhaust gases and controls engine
fuel doser is located in the turbo exhaust duct, directly
operating parameters for emission processing
after the low-pressure turbocharger, on the engine.
and failure recognition
Control of the down stream injection is done by the
•
Cancels regeneration in the event of catalyst or
Engine Control Module (ECM). The ECM receives
sensor failure
data from the aftertreatment sensors directly and
determines when regeneration is required.
•
Monitors the level of soot accumulation in the
Diesel Particulate Filter (DPF) and adapts engine
Pre-Diesel Oxidation Catalyst (PDOC)
operating characteristics to compensate for
increased back pressure
The PDOC is located on the engine after the DSI.
•
Controls engine operating parameters to make
The PDOC does the following:
regeneration automatic
•
Aids in creating an exothermic reaction to improve
•
Maintains vehicle and engine performance during
exhaust emissions
regeneration
•
Allows for more efficient operation of the
aftertreatment system
Sensors
Sensors output an electronic signal based on oxygen
Diesel Oxidation Catalyst (DOC)
(O2), temperature and pressure. The signals are used
The DOC is located in the vehicle exhaust system.
by the control system to regulate the aftertreatment
function.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
23
The DOC does the following:
•
Allows for oxidation
(regeneration) of stored
particulates once back pressure increases to a
•
Oxidizes hydrocarbons and carbon monoxide
predetermined level
(CO) in exhaust stream
•
Stores noncombustible ash
•
Provides heat for exhaust system warm-up
•
Aids in system temperature management for the
AFT Conditions and Responses
DPF
The operator is alerted audibly or with instrument
panel indicators of system status. Automatic or
Diesel Particulate Filter (DPF)
manual regeneration is required when levels of soot
The DPF is located in the vehicle exhaust system.
exceed acceptable limits. For additional information
see the applicable Vehicle Operator Manual and the
The DPF does the following:
vehicle visor placard.
•
Captures and temporarily stores carbon-based
particulates in a filter
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

24
1 ENGINE SYSTEMS
Aftertreatment Fuel Injection Components
Figure 13
Aftertreatment fuel injection components
1.
Fuel doser
4.
Doser fuel from valve tube
6.
Doser fuel to injector tube
2.
Coolant supply port
assembly
assembly
3.
Coolant return port
5.
Feed Injector unit tube assembly
7.
Down Stream Injection (DSI)
assembly
The down stream injection system includes the
•
Fuel lines
following:
The Engine Control Module (ECM) is mounted on the
•
Engine Control Module (ECM)
left side of the engine. The Down Stream Injection
(DSI) assembly is installed on the left rear of the
•
Fuel doser
engine below the cylinder head.
•
Down Stream Injection (DSI) assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
25
When the ECM signals the AFTFSV to open, fuel
pressure increases in the upstream cavity of the
DSI assembly housing. The upstream AFTFIS
immediately signals the ECM that pressure is
increased by available fuel. The ECM then signals
the AFTFD valve to open, allowing a specific amount
of fuel to be pumped through the three fuel tubes to
the fuel doser.
Fuel is injected into the exhaust stream from the fuel
doser which increases the temperature inside the
Diesel Particulate Filter (DPF) in order to convert soot
to ash more efficiently.
The fuel doser is cooled with engine coolant.
Figure 14
Down Stream Injection (DSI) assembly
1.
AFT fuel inlet sensor (AFTFIS) (press and temp)
2.
AFT fuel doser (AFTFD) (valve)
3.
AFT fuel pressure 2 (AFTFP2)
4.
AFT fuel shut-off valve (AFTFSV)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

26
1 ENGINE SYSTEMS
Fuel Management System
Figure 15
Fuel supply system flow
The MaxxForce® 15 engine is equipped with a
Fuel is drawn from the tank and through the frame
high-pressure common rail injection system. The
mounted fuel filter/water separator by a low-pressure
common rail fuel injection system provides fuel under
fuel pump mounted on the engine. Fuel flows from
constant high-pressure to the fuel injectors for optimal
the low-pressure fuel pump through an engine
fuel atomization in the combustion chamber.
mounted fuel filter before being supplied to a
high-pressure pump.
The high-pressure pump
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
27
supplies high-pressure fuel to a pressure pipe rail,
Chassis Mounted Components
which feeds the injectors through individual tubes.
Unused fuel from injectors is returned to the tank
through a passage around the quill tubes in the
cylinder head. The low-pressure fuel pump and
high-pressure pump are assembled as one gear
driven unit on the engine.
The fuel system is controlled by the ECM, various
sensors, and the Fuel Pressure Control Valve (FPCV)
located in the high-pressure pump.
In addition to providing high-pressure fuel to the
injectors, the fuel system also provides low-pressure
filtered fuel to the aftertreatment and cold start assist
systems.
DSI and Fuel Doser
In the aftertreatment system, filtered fuel from the
fuel filter at supply pressure is delivered to the DSI
assembly. The DSI assembly supplies precise
amounts of fuel to the fuel doser.
Cold Start System
During cold weather, fuel is delivered to the Cold
Start Fuel Igniter (CSFI) through the Cold Start Fuel
Solenoid (CSFS). The CSFI then heats the intake air
by injecting and igniting small quantities of fuel into
the mixing duct.
Fuel Filter and Housing
Figure
16
Racor® fuel filter assembly
An orifice and an additional regulator located within
the fuel filter housing work together to reduce fuel
1.
Fuel outlet
pressure to 10 psi for the cold start system solenoid.
2.
Fuel primer pump assembly
Supply system pressure is regulated by a pressure
3.
Fuel inlet from tank
regulator valve located in the supply pump. Excess
4.
Fuel filter water separator assembly
fuel relieved to achieve the pressure reduction is
5.
Water In Fuel (WIF) sensor
returned back to the fuel pump. The maximum
6.
Drain valve
system pressure is regulated to 1 300 kPa (189 psi).
Fuel Filter and Water Separator Assembly
The Racor® fuel filter/water separator
assembly
is standard equipment. There is also an optional
Davco®fuel filter water separator available depending
on customer needs.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

28
1 ENGINE SYSTEMS
Fuel Primer Pump Assembly
the low-pressure fuel pump. The fuel primer pump
assembly is manually operated and is used to prime
The fuel is drawn from the tank through the chassis
the low-pressure fuel system when the system is
fuel filter and water separator assembly, through the
emptied.
chassis mounted fuel primer pump assembly and into
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
29
Engine Mounted Components
Figure 17
Engine mounted fuel system components
1.
Injector (6)
5.
Pressure relief valve
8.
Fuel Pressure Control Valve
2.
Engine Control Module (ECM)
6.
Fuel filter (low pressure)
(FPCV)
3.
Fuel Rail Pressure (FRP) Sensor
7.
Fuel Delivery Pressure (FDP)
9.
Fuel pump (low and
4.
Rail assembly
sensor
high-pressure)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

30
1 ENGINE SYSTEMS
ECM
Rail Assembly (Fuel Common Rail)
The ECM controls the fuel pressure with a PWM
The fuel common rail is a high-pressure fuel storage
signal to the Fuel Pressure Control Valve (FPCV).
unit. The storage volume of the fuel common rail is
Low pulse width PWM signals equal high-pressure
designed to reduce pressure pulses caused by the
and high pulse width signals equal low pressure. To
high-pressure pump and injectors, and to maintain
protect the system, a PLV (Pressure Limiting Valve)
constant fuel pressure even when large fuel quantities
is installed in the end of the fuel rail. When pressure
are injected into the cylinders. Connection between
exceeds 2,650 +/- 100 bar (38,435 +/-1,450 psi), the
the fuel common rail and injectors are made through
PLV opens and reduces pressure to 1,000-1,200 bar
individual injection lines.
(14,503-17,404 psi) to facilitate limp-home operation.
Fuel Rail Pressure (FRP) Sensor
The fuel system is controlled by the ECM. Various
engine sensors are input into fueling calculations. The
The FRP sensor is a variable resistance sensor that
ECM then controls the FPCV and the injectors for
monitors the fuel pressure in the high-pressure fuel
proper engine operation. The injection timing and
rail.
quantity are calculated in the Engine Control Module
The FRP sensor is mounted in the front of the
(ECM) and implemented by solenoid valve controlled
high-pressure pipe rail on the left side of the engine.
injectors.
Pressure Relief Valve
Fuel Filter
The pressure relief valve maintains fuel pressure in
The fuel filter housing assembly is located on the
the rail assembly below 265 000 kPa (38,500 psi).
left side of the engine and has a disposable spin-on
If the rail assembly pressure exceeds this value, the
type filter element. An Engine Fuel Delivery Pressure
relief valve opens and allows fuel to flow to the return
(FDP) sensor is installed on the front side of the
line, and back to the tank. When the relief valve
fuel filter housing assembly and it measures fuel
opens, the system goes into a limp-home mode and
pressure between the low-pressure fuel pump and
a steady rail pressure of 120 000 kPa (17,400 psi) is
the filter element. An additional function of the fuel
maintained until the engine is switched off. This will
filter housing assembly is fuel system self-deaeration.
reset to normal operation upon the next key-in event.
The air separated from fuel is pushed back into the
fuel tanks through the return line.
Injector
The fuel filter housing assembly is equipped with
The MaxxForce®
15
engine is equipped with
two additional ports to provide filtered fuel to the
electronically controlled solenoid valve injectors.
aftertreatment system and to the cold start assist
During engine operation, injectors are supplied at
system. An orifice regulator is integrated into the
all times with high-pressure fuel, and the injector
fuel filter housing assembly and regulates the fuel
solenoid valves open up to three times per cycle. The
pressure for the cold start assist system to 70 kPa
injectors are positioned vertically in the center of the
(10 psi).
cylinder head and are held in place by injector clamps.
The seal between the injectors and the combustion
Fuel Pump
chamber consists of a copper washer on the tip of
Fuel injection pressure is generated by the
each injector.
high-pressure side of the fuel pump. High-pressure
The use of solenoid valve controlled injectors allows
fuel quantity from the fuel pump is controlled by
three injections per cycle. The first injection is
a FPCV. The fuel pump supplies both low and
used to reduce combustion noise and emissions by
high-pressure fuel from one unit. The fuel pump
introducing a small amount of fuel into the cylinder,
is gear driven and is fuel lubricated. Fuel from the
preventing a rapid rise in cylinder pressure when
low-pressure side is forced through the fuel filter
combustion begins.
This first injection occurs
housing assembly and into the high-pressure side of
only during idling and in partial load mode. The
the fuel pump. The flow of fuel to the suction chamber
second injection is the main injection. This injection
of the high-pressure pump is controlled by the FPCV
allows high temperatures to be maintained during
in order to control the high-pressure fuel output.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
31
combustion, but not long enough to allow generation
of large soot amounts. The third injection is done
during the power stroke to maximize cylinder
temperature and reduce engine soot generation.
Engine Lubrication System
Figure 18
Oil system overview (typical)
Engine oil pressure is generated by an oil pump
The front of the crankcase contains oil passages
located under the oil pan which is driven off the
that supply oil to the gear train and air compressor.
crankshaft gear. The oil cooler and filter housing
These passages ultimately supply oil to the cylinder
are located on the right side of the engine. The oil
head through the front hollow dowel that locates the
pump contains the oil pressure regulator. Oil flows to
cylinder head to the engine block. Oil drains back to
the cylinder head by means of an internal passage.
the crankcase through passages in the cylinder head.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

32
1 ENGINE SYSTEMS
Oil Flow and Components
Figure 20
Oil flow through filter when oil is warm
1.
Main oil gallery
Figure 19
Oil flow through filter when oil is cold
2.
Turbocharger oil supply line
1.
Main oil gallery
3.
Turbocharger oil drain tube
2.
Turbocharger oil supply line
4.
Oil filter element
3.
Turbocharger oil drain tube
5.
Bypass valve (oil filter)
4.
Oil filter element
6.
Oil pan
5.
Bypass valve (oil filter)
7.
Oil pump
6.
Oil pan
8.
Bypass valve (oil cooler)
7.
Oil pump
9.
Oil pick-up tube
8.
Bypass valve (oil cooler)
10. Engine oil cooler
9.
Oil pick-up tube
10. Engine oil cooler
When the oil is warm, unfiltered oil is drawn from the
oil pan through the pick-up tube to the oil pump. The
When the engine oil is cold, oil is drawn from the
oil pump pushes the warm oil through the oil cooler
oil pan through the pick-up tube to the oil pump.
towards the oil filter. The bypass valves will be closed
Due to the high viscosity of the cold oil, both bypass
due to the lower viscosity of the oil and its ability to
valves open. These bypass valves provide immediate
flow through the oil cooler and oil filter. Filtered oil is
lubrication to engine components when cold oil with
directed to the turbocharger oil supply line and main oil
high viscosity may not pass through the oil filter easily.
gallery where it is distributed to engine components.
The bypass valves allow oil to bypass the engine oil
Oil that exits the oil cooler flows through a return
cooler and oil filter.
shutoff valve that prevents the oil from draining back
The bypass valve will also allow oil to bypass the oil
into the oil pan. From the return shutoff valve, oil
filter in case the oil filter becomes restricted. This
enters the oil filter element and flows from the outside
prevents a restricted oil filter from blocking oil flow to
to the inside of the filter element to remove debris.
engine components.
When the filter is restricted, an oil filter bypass valve
opens and allows oil to bypass the filter so engine
lubrication is maintained. If the oil pressure inside
the oil filter element is too high, an oil pressure relief
valve, located at the bottom of the oil filter element
housing, allows excess oil to flow to the oil gallery.
Clean oil enters the crankcase directly from the
oil filter housing to lubricate the crankshaft, air
compressor, intermediate gears, and turbochargers.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
33
The crankshaft has cross-drillings that direct oil to the
housing to the center housing of each turbocharger.
connecting rods.
Oil drains back to the oil pan through the low and
high-pressure turbocharger oil return tubes connected
Piston cooling jets continuously direct cooled oil to the
to the crankcase.
bottom of the piston crowns.
The turbochargers are lubricated with filtered oil from
an external supply tube that connects the oil filter
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

34
1 ENGINE SYSTEMS
Engine Cooling System
Cooling System Components
Figure 21
Cooling system components
1.
EGR coolant tube assembly
4.
EGR coolant tube assembly
8.
Water pump inlet
(primary EGR cooler)
(secondary EGR cooler)
9.
Coolant Control Valve (CCV)
2.
EGR coolant return (secondary
5.
Engine Coolant Temperature 1
assembly
EGR cooler)
(ECT1) sensor (behind ISC)
10. Coolant adapter
3.
EGR coolant return (primary
6.
Thermostat housing cover
11. Engine Coolant Pressure 1
EGR cooler)
7.
Water pump
(ECP1) sensor
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
35
Cooling System Flow
Figure 22
Cooling system flow
The water pump is located on the front cover and
the thermostat can direct into two directions to exit
draws coolant from the radiator through the coolant
the cylinder head.
inlet at the lower right side of the engine. The water
When the thermostat is closed, coolant is directed
pump pushes coolant to the oil cooler through a
through the bypass port, crankcase and front cover,
passage in the front cover.
and into the water pump.
Coolant flows to the crankcase and through the water
When the thermostat is open, the bypass port is
jacket from rear to front. This coolant flows around
blocked, and coolant is directed from the engine into
the cylinder liners to absorb heat from combustion.
the radiator. Coolant passes through the radiator
The coolant may also pass through an optional engine
and is cooled by moving air from the radiator fan.
coolant heater.
The coolant returns to the engine first through the
Coolant flows through the cylinder head water jackets
transmission cooler, then through the engine water
towards the thermostat cavity at the front of the
inlet pipe.
cylinder head. Depending on coolant temperature,
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

36
1 ENGINE SYSTEMS
The air compressor is cooled with engine coolant
The surge tank provides expansion space for coolant
supplied by a hose from the left side of the crankcase.
and deaerated the cooling system. The following four
Coolant passes through the air compressor cylinder
vents provide coolant to the tank:
head and returns through a hose back into the
•
Rear and Front EGR Cooler
crankcase through the engine water inlet pipe.
•
Main radiator vent
The fuel doser is also cooled with engine coolant
supplied by the oil cooler module. Coolant passes
•
Low temperature radiator vent
through the fuel doser and is returned to the engine
The surge tank returns coolant through the surge line,
water inlet pipe.
back to the water pump inlet. Cab heat is provided by
The oil cooler assembly receives coolant from the
the heater core, which receives warmed coolant from
front cover water outlet pipe. Coolant passes between
the coolant supply housing.
the oil cooler plates and returns to the crankcase.
Coolant from the water pump also flows through
Thermostat Operation
an external pipe to the rear EGR cooler and to the
front EGR cooler. Coolant passes between the EGR
The MaxxForce®
15
engine is fitted with two
cooler plates. Rear EGR cooler section coolant
thermostats in a common housing to ensure
travels parallel to the exhaust flow. The front EGR
sufficient coolant flow in all operating conditions.
cooler section coolant flows opposite to the exhaust
The thermostats are located at the front of the engine
flow. The coolant from the rear EGR cooler is then
on the right side of the cylinder head.
returned to the water inlet pipe. The coolant from the
The thermostat housing assembly has two outlets.
front EGR cooler is returned to an external pipe to
One directs coolant to the radiator when the engine is
the back of the oil cooler module. Deaeration ports
at operating temperature. The second outlet directs
are located on the top of both the rear and front EGR
coolant to the water pump until the engine reaches
coolers which directs coolant and trapped air to the
operating temperature. The thermostats begin to
coolant surge tank.
open at 88°C (190°F) and are fully open at 103°C
Coolant from the water pump also flows through
(217°F).
the Interstage cooler to regulate the charge air
When engine coolant is below 88°C (190°F), the
temperature. Flow through the Interstage cooler is
thermostats are closed and block coolant flow to the
controlled by the Coolant Controlled Valve (CCV).
radiator. Coolant is forced to flow through a bypass
Depending on the coolant flow, CCV sends coolant
port back to the water pump.
through the Low Temperature Radiator
(LTR) or
bypass directly to the Interstage Cooler (ISC). When
When coolant temperature reaches the opening
the charge air temperature is too low, CCV bypasses
temperature of 88°C (190°F), the thermostats open
the LTR and directs all the coolant through the ISC.
and allow some coolant to flow to the radiator. When
When the charge air temperature increases, CCV
coolant temperature exceeds
103°C (217°F), the
directs a percentage of coolant to the LTR before it
lower seat blocks the bypass port and directs full
enters the ISC to cool the charge air. If the engine
coolant flow to the radiator.
coolant temperature is too high, CCV sends all of the
coolant flow through the LTR and through the ISC to
help cool the engine faster.
Coolant Control Valve (CCV) Assembly Operation
Coolant from the CCV also flows to the EGR valve.
The CCV assembly is installed on the lower right side
Flow through the EGR valve is supplied by an external
of the engine and controls coolant flow to the ISC,
pipe that also supplies to the Interstage cooler. The
EGR valve, and LTR.
EGR valve coolant flow is then returned to the top port
The CCV assembly has two separate solenoid
of the surge tank.
actuated valves: Coolant Mixer Valve (CMV) and
Coolant Flow Valve
(CFV). The CMV and the
CFV are part of the CCV assembly and cannot
be serviced separately. The CMV and CFV solenoids
are controlled by two separate Pulse Width Modulated
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
37
(PWM) signals from the ECM. The PWM signal duty
CMV
cycles vary between 0% and 100% depending on the
The mixing valve varies the amount of coolant that
coolant and charge air temperature.
passes through the low temperature radiator, or LTR.
With a 0% signal to the mixing valve, all coolant flows
CFV
to the LTR before entering the ISC and the EGR valve.
The flow valve varies the rate of coolant flow to the
When 100% duty cycle is applied to the mixing valve,
mixing valve. At 0% duty cycle the flow valve is fully
full coolant flow bypasses the LTR and is directed to
open and coolant to the mixing valve is not restricted.
the ISC and EGR valve.
When the flow valve receives 100% duty cycle, it
partially closes restricting coolant to the mixing valve.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

38
1 ENGINE SYSTEMS
MaxxForce®Engine Brake System
brake housing assemblies. This provides progressive
braking capabilities with the retarding effect of two
The MaxxForce®engine brake is standard equipment
cylinders, four cylinders, or all six cylinders.
on the MaxxForce® 15L engine. The engine brake
uses engine oil pressure to improve the engine
braking power by holding the exhaust valves slightly
open during the cylinder compression and power
strokes.
During engine brake operation, both the compression
and expansion strokes of the power cylinders are used
to absorb road speed energy through the powertrain.
The operator can enable or disable the engine brake
by pressing a dash mounted ON/OFF switch.
Engine Brake System Components
Figure 23
Engine brake housing
1.
Slave piston
2.
Master piston
3.
Slave piston adjustment screw
4.
Engine brake solenoid and spool valve
The engine brake consists of three identical housing
assemblies; each housing is positioned over two
cylinders. The housing assembly is mounted to the
supports for the rocker shaft assembly with studs and
nuts. The rocker arm and exhaust bridge assembly
is used to transfer force from the slave piston to the
exhaust valves.
The engine brake is controlled by the ECM. The
control circuit for the engine brake permits the
operation of either one, two, or all three engine
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
39
Figure 24
Engine brake system
1.
Check valve
7.
Slave piston
13. Rocker arm shaft oil passage
2.
High-pressure oil passage
8.
Master piston spring
14. Engine oil pump
3.
Slave piston adjustment screw
9.
Slave piston spring
15. Engine oil pan
4.
Master piston
10. Exhaust rocker arm
16. Exhaust valve
5.
Spool valve
11. Exhaust bridge
17. Lost motion assembly
6.
Oil drain passage
12. Lost motion rocker arm
Engine Brake Operation
arm. Oil fills the master cylinder and high-pressure
oil passage between the master cylinder and slave
The engine brake is operated by pressurized engine
cylinder. The master piston will follow the movement
oil. Engine oil is supplied to the engine brake through
of the lost motion rocker arm. The check valve will
a passage in the rocker shaft assembly. The spool
close when the master piston moves upward causing
valve controls the flow of oil to the engine brake
the pressure in the high-pressure oil passage to rise.
components.
This increase in pressure causes the slave cylinder to
When the spool valve is moved by the engine brake
move downward contacting the exhaust valve bridge
solenoid, low pressure oil passes through the spool
and open the exhaust valves.
valve. The oil flow opens a check valve and flows
The ECM will disable the fuel injectors during engine
into the high-pressure oil passage to supply oil to
brake operation. Without fuel injection or combustion,
the master and slave cylinders. The oil pressure
the power stroke is transformed into an energy
overcomes the spring in the master cylinder and
absorption stroke. This will create an engine braking
forces the master piston toward the lost motion rocker
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

40
1 ENGINE SYSTEMS
force at the flywheel. As the lost motion rocker arm
moves down, the master piston will also move down
and reduce the oil pressure on the slave piston. As a
result, the slave piston will move upward and return
exhaust valve operation to the engine valve train.
De-energizing the solenoid allows oil to drain back into
the engine oil pan through the drain passages in the
spool valve.
Open Crankcase Breather System
Open Crankcase Breather System Components
Figure 25
Open crankcase breather system
1.
Breather inlet tube
3.
Breather outlet tube
2.
Breather filter assembly
4.
Breather drain tube
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
41
Open Crankcase Breather System Operation
breather inlet tube. From the breather inlet tube,
blow-by gases enter the breather filter assembly
The open crankcase breather system uses an engine
where heavy oil particles are separated and drain into
mounted oil separator to return oil to the crankcase
the oil pan through check valves in oil drain tube.
and vent blow-by gases to the atmosphere. The
primary component of the system is the breather filter
The cleaned blow-by gases exit to the atmosphere
in the breather filter assembly. The breather filter
through the breather outlet tube.
separates oil mist from blow-by gases.
The blow-by gases exit the crankcase from the valve
cover and enter the breather system through the
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

42
1 ENGINE SYSTEMS
Cold Start Assist System
Figure 26
Cold start assist system components
1.
Cold Start Fuel Igniter (CSFI)
3.
Cold Star Fuel Solenoid (CSFS)
6.
Cold Start Relay (CSR)
2.
Solenoid to injector tube
4.
Filter to solenoid tube assembly
assembly
5.
Relay support assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
43
Cold Start Fuel Igniter (CSFI)
Cold Start Fuel Solenoid (CSFS)
The CSFS valve is located on the left side of the
engine and is controlled by the ECM. The CSFS valve
is supplied regulated low pressure fuel from the fuel
filter housing assembly through the solenoid to injector
tube.
When the ECM provides 12 volts to the solenoid valve,
the CSFS valve opens and allows fuel to flow to the
CSFI through the solenoid to injector tube. Ground
control is provided by the ECM.
Cold Start Assist System Operation
The cold start assist system operates only in
temperatures lower than 11°C (52°F).
When the vehicle operator turns the ignition switch
Figure 27
Cold Start Fuel Igniter (CSFI)
to ON, the wait-to-start lamp in the instrument cluster
1.
Electrical connection
illuminates. The ECM activates the Cold Start Relay
2.
Insulation
(CSR) based on the temperature readings from
3.
Fuel line connection
the Engine Coolant Temperature (ECT), Engine Oil
4.
Metering device
Temperature (EOT), and the Intake Air Temperature
5.
Vaporizer filter
(IAT) sensors. The CSR then energizes the CSFI for
6.
Vaporizer tube
approximately 45 seconds.
7.
Heater element
Once the CSFI is heated to approximately 1 000°C
8.
Protective sleeve
(1,832°F), the wait-to-start lamp starts to flash and
the operator needs to crank the engine. When the
engine starts rotating, the solenoid valve opens and
The function of the CSFI is to spray ignited fuel into the
allows fuel to enter the CSFI through the solenoid to
mixing duct. The ignited fuel warms incoming air to
injector tube. The fuel passes through the vaporizer
assist starting a cold engine. The CSFI is essentially
tube inside the CSFI. The vaporized fuel then mixes
a fuel injector and glow plug in one unit.
with the intake air and ignites in contact with the heater
The CSFI has an internal fuel metering device, a
element.
vaporizer filter, a vaporizer tube, a heater element,
Once the engine starts, the CSFI remains energized
and a protective sleeve. The protective sleeve has
and fuel continues to be injected to the CSFI, and the
holes that allow enough air to pass through the CSFI
wait-to-start lamp continues to flash for a maximum of
to enable the fuel vaporization and combustion.
4 minutes. When the wait-to-start lamp stops flashing,
The CSFI is installed on the left front side of the engine
the CSFI and the solenoid valve are deactivated. If
in the mixing duct.
the operator accelerates while the wait-to-start lamp
flashes, the cold start assist system will shut down.
Cold Start Relay (CSR)
The CSR is located on the rear left side of the
engine. The CSR provides voltage to the CSFI and is
controlled by the Engine Control Module (ECM).
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

44
1 ENGINE SYSTEMS
Electronic Control System
Continuous calculations in the ECM occur in the
foreground and background.
Electronic Control System Components
•
Foreground calculations are faster than
The MaxxForce® 15 engine is equipped with an
background calculations and are normally more
Engine Control Module
(ECM) that monitors and
critical for engine operation. Engine speed control
controls all functions of the engine and aftertreatment
is an example.
system.
•
Background calculations are normally variables
that change at slower rates. Engine temperature
Operation and Function
is an example.
The Engine Control Module (ECM) monitors and
Diagnostic Trouble Codes (DTCs) are set by the
controls engine performance to ensure maximum
microprocessor if inputs or conditions do not comply
performance and adherence to emissions standards.
with expected values.
The ECM performs the following functions:
Diagnostic strategies are also programmed into the
•
Provide reference voltage (VREF)
ECM. Some strategies monitor inputs continuously
and command the necessary outputs for correct
•
Condition input signals
performance of the engine.
•
Process and store control strategies
•
Control actuators
Diagnostic Trouble Codes
Diagnostic Trouble Codes
(DTCs) are stored by
the ECM if inputs or conditions do not comply with
Reference Voltage (VREF)
expected values. Diagnostic codes for the 2010
The ECM supplies 5 volt VREF signals to input
MY are communicated using the Suspect Parameter
sensors in the electronic control system.
By
Number (SPN) and Failure Mode Indicator (FMI)
comparing the 5 volt VREF signal sent to the sensors
identifiers, and are accessed using an electronic
with their respective returned signals, the ECM
service tool with ServiceMaxx™ diagnostic software
determines pressures, positions, and other variables
or a generic scan tool as well.
important to engine and vehicle functions.
Microprocessor Memory
Signal Conditioner
The ECM microprocessor includes Read Only
Memory (ROM) and Random Access Memory (RAM).
The signal conditioner in the internal microprocessor
converts analog signals to digital signals, squares up
ROM
sine wave signals, or amplifies low intensity signals to
a level that the control module’s microprocessors can
ROM stores permanent information for calibration
process.
tables and operating strategies. Permanently stored
information cannot be changed or lost when the
ignition switch is turned to OFF or when power to
Microprocessor
the control modules is interrupted. ROM includes the
following:
The ECM microprocessor stores operating
instructions
(control strategies) and value tables
•
Vehicle configuration, modes of operation, and
(calibration parameters). The ECM compares stored
options
instructions and values with conditioned input values
•
Engine Family Rating Code (EFRC)
to determine the correct strategy for all engine
operations.
•
Engine warning and protection modes
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
45
RAM
The CFV and CMV are part of the Coolant Control
Valve (CCV) assembly which is mounted on the lower
RAM stores temporary information for current engine
right side of the engine.
conditions. Temporary information in RAM is lost
when the ignition switch is turned to OFF or power
to control module is interrupted. RAM information
Exhaust Gas Recirculation (EGR) Valve Assembly
includes the following:
The EGR valve assembly controls the flow of exhaust
•
Engine temperature
gases entering the EGR cooler assembly.
•
Engine rpm
The EGR valve operates on a Pulse Width Modulated
(PWM) voltage signal from the ECM. The ECM will
•
Accelerator pedal position
then regulate the duty cycle of the PWM voltage signal
to the EGR valve assembly actuator to open or close
the valve as required.
Actuator Control
A sensor within the EGR valve provides feedback to
The ECM controls the actuators by applying a low
the ECM on the valve position. A fault code will be set
level signal (low side driver) or a high level signal (high
if the ECM detects an error.
side driver). When switched on, both drivers complete
a ground or power circuit to an actuator.
The EGR valve assembly is mounted on the rear of the
EGR cooler assembly, on the right side of the engine.
Actuators are controlled in one of the following ways,
depending upon type of actuator:
Air Control Valve
•
Pulse Width Modulated (PWM)
The air control valve controls the wastegate actuator
•
Switched on or off
on the high-pressure turbocharger.
•
CAN messages
The air control valve either applies air pressure to the
wastegate actuator, or vents system pressure to the
atmosphere in response to commands from the ECM.
Actuators
The air control valve is mounted on a bracket on the
The ECM controls engine operation with the following:
right side of the engine, below the secondary EGR
•
Coolant Flow Valve (CFV)
cooler.
•
Coolant Mixer Valve (CMV)
Cold Start Relay (CSR)
•
Exhaust Gas Recirculation (EGR) valve
The cold start assist system aids cold engine starting
•
Air control valves (TC1WC and TC2WC)
by warming the incoming air supply during cranking
•
Cold Start Fuel Solenoid (CSFS)
and initial idling.
•
Cold Start Relay (CSR)
The CSR is a solid state relay that is pulse width
modulated by the ECM to energize the CSFI. The
•
Engine Throttle Valve (ETV)
CSFI is case grounded to the ETV assembly. The total
•
Fuel Pressure Control Valve (FPCV)
time that the CSR energizes the CSFI is dependent on
engine coolant temperature.
Coolant Flow Valve and Coolant Mixer Valve
Cold Start Fuel Solenoid (CSFS)
The Coolant Flow Valve (CFV) controls the maximum
The CSFS valve controls the fuel flow to the CSFI
pressure in the LTR and the Coolant Mixer Valve
during cold start assist operation.
(CMV) regulates the temperature of the coolant
by directing the coolant either through the Low
When the cold start assist is required, the ECM
Temperature Radiator (LTR) or through an internal
provides voltage to open the CSFS valve during
bypass. Both valves are controlled by the ECM.
cranking and initial idling.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

46
1 ENGINE SYSTEMS
The CSFS valve is mounted on the left side of the
decreases as temperature increases, and increases
engine, above the fuel filter.
as temperature decreases. Thermistors work with a
resistor that limits current in the control module to a
voltage signal matched with a temperature value.
Engine Throttle Valve (ETV)
The top half of the voltage divider is the current limiting
The ETV is a variable position actuator that restricts
resistor inside the control module. A thermistor
intake air flow by way of an internal butterfly valve
sensor has two electrical connectors, signal return
to help heat the exhaust aftertreatment during
and ground. The output of a thermistor sensor is a
regeneration, and to assist when heavy EGR is
non-linear analog signal.
requested.
Thermistor type sensors include the following:
The ETV changes butterfly valve position in response
•
Aftertreatment temperature sensors
to ECM signals. The ETV contains an internal
position sensor that monitors butterfly valve position
•
Charge Air Cooler Outlet Temperature (CACOT)
and transmits a position signal to the ECM.
•
Engine Coolant Temperature (ECT) sensors
The ETV is mounted on the left side of the engine.
•
Engine Oil Temperature (EOT) sensor
•
Intake Manifold Temperature (IMT) sensor
Fuel Pressure Control Valve (FPCV)
Aftertreatment Temperature Sensors
The FPCV is a variable position actuator that
regulates fuel pressure in the pressure pipe rail.
Three sensors used in the Aftertreatment System
include the following:
The FPCV changes valve position through pulse width
modulated signals from the ECM. It controls the flow
•
Diesel Oxidation Catalyst Inlet Temperature
of fuel to the suction side of the high-pressure pump.
(DOCIT) sensor
The FPCV is mounted on the high-pressure pump.
•
Diesel Oxidation Catalyst Outlet Temperature
They are serviced as an assembly.
(DOCOT) sensor
•
Diesel Particulate Filer Outlet Temperature
Engine and Vehicle Sensors
(DPFOT) sensor
Thermistor Sensor
The DOCIT sensor provides a feedback signal to
the Engine Control Module (ECM) indicating Diesel
Oxidation Catalyst (DOC) inlet temperature. The
DOCIT sensor is the first temperature sensor installed
past the pre-diesel oxidation catalyst and just before
the DOC.
The DOCOT sensor provides a feedback signal to
the Engine Control Module (ECM) indicating Diesel
Oxidation Catalyst (DOC) outlet temperature. The
DOCOT sensor is installed just after the DOC.
The DPFOT sensor provides a feedback signal to the
ECM indicating DPF outlet temperature. The DPFOT
sensor is installed just after the DPF.
During a DPF regeneration, the ECM monitors these
sensors along with the EGR system and ETV.
Figure 28
Thermistor sensor
A thermistor sensor changes electrical resistance with
changes in temperature. Resistance in the thermistor
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
47
Charge Air Cooler Outlet Temperature (CACOT)
Variable Resistance Sensor
Sensor
Early production engines come equipped with
a CACOT sensor; however, even though it is
electronically connected to the system, it is disabled
in the ECM software and not currently utilized. The
CACOT sensor is installed in the engine throttle valve
assembly.
Engine Coolant Temperature 1 (ECT1) Sensor
The ECT sensor is a thermistor sensor that detects
engine coolant temperature.
This engine has two ECT sensors. The ECT1 sensor
is installed on the right side of the engine behind the
Figure 29
Variable resistance sensor
thermostat assembly. The ECT2 sensor is installed in
the coolant manifold behind the interstage cooler.
Variable resistance sensors measure pressure. The
The ECT1
and ECT2
signals are monitored
pressure measured is applied to a ceramic material.
by the ECM for operation of the instrument
The pressure forces the ceramic material closer to a
panel temperature gauge, coolant temperature
thin metal disk. This action changes the resistance of
compensation, charge air temperature control,
the sensor.
optional Engine Warning Protection System (EWPS),
and the wait-to-start lamp.
The sensor is connected to the control module through
the VREF, signal, and signal ground wires.
Engine Oil Temperature (EOT) Sensor
The sensor receives the VREF and returns an analog
The EOT sensor is a thermistor sensor that detects
signal voltage to the control module. The control
engine oil temperature.
module compares the voltage with pre-programmed
values to determine pressure.
The EOT signal is monitored by the ECM for the
Engine Warning Protection System
(EWPS). The
Variable resistance sensors include the following:
EOT sensor is also used by the oil temperature gauge
•
Exhaust Gas Differential Pressure (EGDP) sensor
in the instrument cluster.
•
Fuel Delivery Pressure (FDP) sensor
The EOT sensor is installed in the side of the oil
module, on the right side of the engine.
•
Engine Oil Pressure (EOP) sensor
•
Fuel Rail Pressure (FRP) sensor
Intake Manifold Temperature (IMT) Sensor
•
Intake Manifold Pressure (IMP) sensor
The IMT sensor is a thermistor sensor that monitors
the temperature of the intake air.
Exhaust Gas Differential Pressure (EGDP) Sensor
EGR operation is shut down under certain
The EGDP sensor provides a feedback signal to
temperature conditions to prevent sulphurous acids
the Engine Control Module
(ECM) indicating the
from condensing under cold charge-air temperatures
pressure difference between the inlet and outlet of
and to protect the engine from excessively hot intake
the particulate filter. The ECM monitors this sensor to
air in the event of an EGR fault.
determine DPF soot levels.
The IMT sensor is installed in the intake channel of the
The EGDP sensor is a differential pressure sensor
cylinder head, on the left side of the engine.
with two tap-offs installed past the turbocharger. A
tap-off is located before and after the DPF.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

48
1 ENGINE SYSTEMS
Engine Fuel Delivery Pressure (FDP) Sensor
Magnetic pickup sensors used include the following:
The FDP sensor is a variable resistance sensor that
•
Crankshaft Position (CKP) sensor
measures fuel supply pressure.
•
Camshaft Position (CMP) sensor
The FDP sensor provides feedback to the ECM for the
•
Vehicle Speed Sensor (VSS)
low-pressure fuel system.
The FDP sensor is installed in the front of the fuel filter
Crankshaft Position (CKP) Sensor
housing assembly on the left side of the engine.
The CKP sensor is a magnetic pickup sensor that
indicates crankshaft speed and position.
Engine Oil Pressure (EOP) Sensor
The CKP sensor sends a pulsed signal to the Engine
The EOP sensor is a variable resistance sensor that
Control Module (ECM) as the crankshaft turns. The
detects engine oil pressure.
CKP sensor reacts to a 58 tooth timing disk on the
The EOP signal is monitored by the ECM for operation
front of the crankshaft. By comparing the CKP signal
of the instrument panel pressure gauge and optional
with the CMP signal, the ECM calculates engine rpm
EWPS.
and timing requirements.
The EOP sensor is installed in the oil pressure sensor
The CKP sensor is installed at the bottom left of the
support, on the left side of the engine.
engine, in the front cover.
Fuel Rail Pressure (FRP) Sensor
Camshaft Position (CMP) Sensor
The FRP sensor is a variable resistance sensor that
The CMP sensor is a magnetic pickup sensor that
monitors the fuel pressure in the pressure pipe rail.
indicates camshaft speed and position.
The FRP sensor measures the fuel pressure just prior
The CMP sensor sends a pulsed signal to the ECM
to injection.
as the camshaft timing ring mounted on the rear of
the camshaft gear rotates past the CMP sensor. The
The FRP sensor is mounted in the front of the pressure
ECM calculates camshaft speed and position from
pipe rail on the left side of the engine.
CMP signal frequency.
Intake Manifold Pressure (IMP) Sensor
The CMP sensor is installed at the top left of the
engine, in the front cover.
The IMP sensor is used to measure the absolute
charge-air pressure.
Vehicle Speed Sensor (VSS)
The IMP sensor is installed in the ETV on top of the
The VSS provides the ECM with transmission tail shaft
engine.
speed by sensing the rotation of a 16-tooth gear on
the rear of the transmission. The detected sine wave
signal (AC) received by the ECM is used with tire
Magnetic Pickup Sensor
size and axle ratio to calculate vehicle speed. The
A magnetic pickup sensor contains a permanent
VSS signal is transmitted over the CAN in vehicles
magnet core that is surrounded by a coil of wire.
with automatic transmission. The VSS is located on
The sensor generates a voltage signal through the
the left side of the transmission housing for automatic
collapse of a magnetic field that is created by a
transmissions, or at rear of the transmission housing
moving metal trigger. The movement of the trigger
for manual transmissions.
then creates an AC voltage in the sensor coil.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
49
Potentiometer
Switches
Figure 31
Switch
Switch sensors indicate position, level, or status.
They operate open or closed, regulating the flow of
Figure 30
Potentiometer
current. A switch sensor can be a voltage input switch
or a grounding switch. A voltage input switch supplies
the control module with a voltage when it is closed.
A potentiometer is a variable voltage divider that
A grounding switch grounds the circuit when closed,
senses the position of a mechanical component.
causing a zero voltage signal. Grounding switches
A reference voltage is applied to one end of the
are usually installed in series with a current limiting
potentiometer. Mechanical rotary or linear motion
resistor.
moves the wiper along the resistance material,
Switches include the following:
changing voltage at each point along the resistive
material. Voltage is proportional to the amount of
•
Driveline Disengagement Switch (DDS)
mechanical movement.
•
Engine Coolant Level (ECL)
The engine has two potentiometers, both contained in
the Accelerator Pedal Position (APP) sensor.
Driveline Disengagement Switch (DDS)
The DDS determines if a vehicle is in gear. For
Accelerator Pedal Position (APP) Sensors
manual transmissions, the clutch switch serves as
The dual track APP sensor provides the ECM with a
the DDS. For automatic transmissions, the neutral
feedback signal (linear analog voltage) that indicates
indicator switch or datalink communication functions
the operator’s demand for power. The dual track APP
as the DDS.
sensor is installed in the cab on the accelerator pedal.
Engine Coolant Level (ECL) Switch
The ECL switch is part of the Engine Warning
Protection System
(EWPS). The ECL switch is
located on the deaeration tank. When the magnetic
switch is open, the tank is considered full of coolant.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

50
1 ENGINE SYSTEMS
If engine coolant is low, the switch closes and the red
corresponds to the oxygen levels in the exhaust
ENGINE lamp on the instrument panel is illuminated.
stream.
The O2S is installed in the turbocharger exhaust duct.
Oxygen Sensor (O2S)
The O2S monitors oxygen levels in exhaust gases.
Turbocharger 2 Compressor Inlet Sensor (TC2CIS)
The O2S is used to tune the engine operation to a
Early production engines will be equipped with a
specified air-to-fuel ratio.
TC2CIS, however this sensor is not used by the
engine control system at this time.
The O2S compares oxygen levels in the exhaust
stream with oxygen levels in the outside air. It
The TC2CIS is installed in the low-pressure
then generates a voltage that is transmitted to the
turbocharger compressor outlet duct.
ECM. The level of voltage generated by the O2S
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

2 ENGINE AND VEHICLE FEATURES
51
Table of Contents
Standard Electronic Control Features
53
Aftertreatment (AFT) System
53
Cold Ambient Protection (CAP)
53
Cold Start Assist
53
Coolant Temperature Compensation (CTC)
53
Data Plate
53
Electronic Speedometer and Tachometer
54
Engine Crank Inhibit (ECI)
54
Engine Electronic Governor Control
54
Engine Fan Control
54
Event Logging System
54
Fast Idle Advance
54
J1939 Datalink
55
Password Protection
55
Service Diagnostics
55
Trip Reporting
55
Vehicle Setup
55
Optional Electronic Control Features
56
Cruise Control
56
Driver Reward
56
MaxxForce® Engine Brake
56
Engine Warning Protection System (EWPS)
56
Gear Down Protection
56
Idle Shutdown Timer (IST)
57
Progressive Shift
57
Power Take Off (PTO) – In Cab
57
Power Take Off (PTO) – Remote
57
Service Interval
58
Traction Control
58
Upshift Indicator
58
Road Speed Limiter
58
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

52
2 ENGINE AND VEHICLE FEATURES
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

2 ENGINE AND VEHICLE FEATURES
53
Standard Electronic Control Features
2
(ECT2) sensors. When the key is turned to the
ON position, the ECM monitors the ECT2 and AIT
NOTE: For the latest complete feature operation,
sensors. If either sensor is below 11°C (52°F), the
and parameter information, use the MaxxForce® 15
ECM enables the CSR. The CSR energizes the Cold
Engine Feature Documentation found under the Body
Start Fuel Igniter (CSFI). When the CSFI reaches
Builder Website Link within International Service
the proper operating temperature, the wait to start
Information Solutions (ISIS). This includes parameter
lamp flashes. As the engine is cranked, the ECM
details of description, possible values, whether or
energizes the Cold Start Fuel Solenoid (CSFS) valve,
not it is customer programmable, and recommended
introducing fuel into the CSFI, which ignites and
settings.
warms the air being drawn into the engine. Do not
Aftertreatment (AFT) System
accelerate the engine until the wait to start lamp goes
out.
The AFT system, part of the larger exhaust system,
processes engine exhaust so that it meets tailpipe
For additional information, see Cold Start Assist
emission requirements. The AFT system traps
System in the
“Engine Systems” section of this
particulate matter (soot) and prevents it from leaving
manual.
the tailpipe.
The trapped particulate matter is
then rendered to ash by heating the exhaust and
injecting fuel through a process called regeneration.
Coolant Temperature Compensation (CTC)
Regeneration reduces the frequency of AFT system
NOTE: CTC is disabled in emergency vehicles and
maintenance without adversely affecting emissions.
school buses that require
100 percent power on
For additional information, see Aftertreatment (AFT)
demand.
System in the
“Engine Systems” section of this
CTC reduces fuel delivery if the engine coolant
manual.
temperature is above cooling system specifications.
Before standard engine warning or optional
Cold Ambient Protection (CAP)
warning/protection systems engage, the ECM
begins reducing fuel delivery when engine coolant
CAP protects the engine from damage caused by
temperature reaches approximately 107°C (225°F).
prolonged idle at no load condition during cold
A rapid fuel reduction of 15 percent is achieved when
weather.
engine coolant temperature reaches approximately
CAP maintains engine coolant temperature by
110°C (230°F).
increasing engine rpm. CAP also improves cab
warm-up.
Data Plate
CAP is standard on trucks without an Idle Shutdown
Timer (IST).
The ECM stores data to help identify the vehicle and
engine components. The data plate feature is used
to display text data descriptions in order to assist with
Cold Start Assist
reports and make data tracking easier.
The cold start assist feature improves engine startup
The parameters associated with this feature only
in cold weather. The Engine Control Module (ECM)
need to be modified when a related component is
controls the Cold Start Relay (CSR) and monitors
replaced, and can only be updated through your
the Engine Oil Temperature
(EOT), Air Intake
authorized dealer.
Temperature (AIT) and Engine Coolant Temperature
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

54
2 ENGINE AND VEHICLE FEATURES
Electronic Speedometer and Tachometer
The primary purpose of the engine fan is to allow the
engine to run at its regulated operating temperature
The engine control system calibrates vehicle speed
increasing engine performance. It is also used to
up to 157,157 pulses per mile. The calculated vehicle
assist in cooling the refrigerant in the A/C condenser.
speed is a function of transmission tail shaft speed,
Factory set parameters within the ECM provide
number of teeth on the tail shaft, rear axle ratio, and
engine fan control based on the fan type installed in
tire revolutions per mile. Use the Electronic Service
the vehicle. Choosing whether the fan is engaged
Tool (EST) with ServiceMaxx™ software to program
during engine speed control, commonly referred
new speed calibrations into the ECM.
to as PTO, operation is a customer programmable
The tachometer signal is generated by the ECM by
parameter. For additional information, see EFC
computing the signals from the Camshaft Position
(Engine Fan Control) in the
“Electronic Control
(CMP) sensor and the Crankshaft Position (CKP)
Systems Diagnostics” section of this manual.
sensor. The calculated engine speed is then sent to
the instrument cluster through the J1939 CAN Data
Link.
Event Logging System
The event logging system records vehicle operation
above the maximum speed setting (overspeed) and
Engine Crank Inhibit (ECI)
engine operation above maximum rpm (overspeed),
The ECI will not allow the starting motor to engage
coolant temperature out of operational range, low
when the engine is running and the drivetrain is
coolant level, or low oil pressure. The readings for
engaged.
the odometer and hourmeter are stored in the ECM
memory at the time of an event and can be retrieved
The ECI will not allow the starting motor to engage
using the EST.
with the engine running if the key is turned to START
while the clutch pedal is pressed.
Fast Idle Advance
Engine Electronic Governor Control
The ECM monitors the Engine Coolant Temperature
(ECT) sensor. If the engine coolant temperature is
The governor controls engine rpm within a safe and
below 10°C (50°F), the ECM activates the fast idle
stable operating range.
advance.
The low idle governor prevents engine rpm from
Fast idle advance increases engine idle speed to 700
dropping below a stable speed to prevent stalling
rpm for a period of up to 100 seconds to assist in faster
when various loads are demanded on the engine.
warm-up to operating temperature. This occurs by the
The high idle governor prevents engine rpm from
ECM monitoring the engine coolant temperature and
going above a safe speed that would cause engine
adjusting the fuel injector operation accordingly.
damage.
Low idle speed is resumed when engine coolant
temperature reaches temperatures above
10°C
(50°F), or the 100 second period times out.
Engine Fan Control
The engine fan control feature is designed to allow
configuration of the engine for various fan control
features on a particular vehicle application.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

2 ENGINE AND VEHICLE FEATURES
55
J1939 Datalink
prevent unauthorized users from changing parameter
values in the ECM. With the password set, the
The vehicle is equipped with an Society of Automotive
service tool will prompt for the current password and
Engineers (SAE) standard J1939 CAN datalink:
will not allow any parameter to be changed until that
•
The J1939 datalink is used for diagnostics and
password is entered. The password parameter is
calibration communications for the Engine Control
customer programmable.
Module (ECM).
•
The J1939 datalink is used for communications
Service Diagnostics
between the ECM, Electronic Gauge Cluster
(EGC), and Body Controller (BC).
The EST provides diagnostic information using the
J1939 datalink.
The J1939 datalink is accessed through the cab
diagnostic connector pins C and D. The datalink
Faults from sensors,
actuators,
electronic
provides communication between the ECM and the
components,
and engine systems are detected
Electronic Service Tool (EST).
by the ECM. The faults are accessed by the EST
through the Diagnostic Connector, and are displayed
The J1939 datalink supports:
as Diagnostic Trouble Codes (DTCs) on the EST.
•
Transmission of engine parameter data
Effective engine diagnostics require and rely on
DTCs.
•
Transmission and clearing of Diagnostic Trouble
Codes (DTCs)
•
Diagnostics and troubleshooting
Trip Reporting
•
Programming engine and vehicle features
The trip reporting feature is designed to monitor,
collect, and store engine related operational
•
Programming calibrations and strategies
information. This information can be downloaded
•
Inter-module communications between the:
and organized into useful reports using a service tool.
Trip reporting operational data is recorded in two
•
Engine Control Module (ECM)
ways; non-resettable cumulative data, which consists
•
Body Controller (BC)
of running totals, and resettable trip data, which
consists of data collected since the last trip reset.
•
Electronic Gauge Cluster (EGC)
•
Automatic Transmission Controller
Vehicle Setup
•
Electronic Service Tool (EST)
The vehicle
setup feature consists of various
For additional information, see J1939 Datalink in the
parameters within the ECM, which are based
“Electronic Control Systems Diagnostics” section in
on the vehicle configuration.
Most parameters
this manual.
are pre-programmed by the original equipment
manufacturer
(OEM) and will not require any
adjustment for the life of the vehicle.
Password Protection
The ECM allows the vehicle to be configured to help
the owner optimize fuel economy and reliability. The
password protection feature provides protection to
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

56
2 ENGINE AND VEHICLE FEATURES
Optional Electronic Control Features
Programmable parameters within the ECM provide
engine brake related options that can be adjusted
NOTE: For the latest complete feature operation,
to suit the customer’s needs. Choosing whether the
and parameter information, use the MaxxForce® 15
engine brake is activated by pressing the service
Engine Feature Documentation found under the Body
brake pedal or by releasing the accelerator pedal
Builder Website Link within ISIS®. This includes
is one example. For a detailed feature description,
parameter details of description, possible values,
see Engine Brake System in the “Engine Systems”
whether or not it is customer programmable, and
section of this manual.
recommended settings.
Cruise Control
Engine Warning Protection System (EWPS)
Cruise Control is a well-known feature that offers
driving comfort by providing a method for an operator
NOTE: Emergency vehicles are not equipped with
to set and maintain a constant vehicle speed without
EWPS.
using the accelerator pedal. It is especially useful
The Engine Warning and Protection System (EWPS)
when the operator is required to drive on highways at
feature is designed to protect the engine from damage
a constant speed for many miles.
by monitoring critical engine data such as the engine
This cruise control feature is unique due to a
speed, temperature, oil pressure, and coolant level.
parameter, which allows the cruise control set speed
The EWPS feature will alert the operator by using a
to be maintained in the ECM memory. Additional
combination of visual and audible warnings if critical
programming flexibility is included to allow a trade-off
engine parameters are exceeded. Depending on the
to be made between performance and fuel economy.
severity of the problem, there may be a reduction in
power associated with the visual warnings. EWPS
also visually alerts the operator with an amber warning
Driver Reward
lamp if the vehicle speed exceeds a threshold. The
vehicle overspeed incidents are logged and can be
The driver reward feature is designed to give the
downloaded into a report. Refer to the “Trip Reporting”
operator incentives for driving more efficiently. The
feature for more information.
feature accomplishes this by measuring the driver’s
habits based on fuel economy, time at idle, or both.
Customer programmable parameters within the ECM
provide EWPS related options that can be adjusted
The rewards include higher maximum vehicle speed
to suit the customer’s needs. For example the
and higher cruise control speed limit. Lower maximum
customer may choose that the EWPS feature activate
vehicle speed or cruise control speed limits may result
a flashing red lamp and audible warning 30 seconds
as a penalty for failing to meet the standards.
before engine shut down, to provide an additional
Customer programmable parameters within the ECM
level of engine protection.
provide driver reward related options that can be
adjusted to suit the customer’s needs.
Gear Down Protection
The Gear Down Protection (GDP) feature is designed
MaxxForce® Engine Brake
to encourage the driver to operate in the engine’s
The engine brake feature is a hydro-mechanical
most efficient range for fuel economy. This is done
device designed to help decelerate the vehicle by
by limiting the vehicle speed until the driver shifts into
providing additional engine load. It mounts under the
a higher gear. This encourages the driver to upshift
engine valve cover and turns your power-producing
to the next highest gear, and helps to maintain the
diesel engine into a power-absorbing air compressor.
engine’s most efficient speed range for fuel economy.
This will reduce brake wear in vehicles which
There are several customer programmable
require frequent braking. This feature assumes
parameters for this feature.
the vehicle is equipped with a factory installed
engine brake system; otherwise there may be engine
components, additional switches, harnesses, and
software modifications which may also be required.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

2 ENGINE AND VEHICLE FEATURES
57
Idle Shutdown Timer (IST)
The in-cab engine speed control feature provides
three conditions in which the operator may select
The idle shutdown timer is used to limit the amount of
PTO speeds:
engine idle time by automatically shutting down
the engine after a pre-programmed time has
•
Stationary Preset – Permits the operator to select
expired. Programmable parameters within the ECM
up to six preset speeds while the vehicle is
determine the time and conditions required before the
stationary
engine shuts down. Some customer programmable
•
Stationary Variable Speed – Permits the operator
parameters provide idle shutdown related options that
to select any engine speed within the PTO
can be adjusted to suit the customer’s needs.
boundaries
Thirty seconds before engine shutdown occurs, there
•
Mobile Variable Speed – Permits the operator
will be an amber lamp illuminated in the instrument
to select a desired variable speed for moving or
panel (if equipped) and an audible warning will sound.
stationary PTO operations
This will continue until the engine shuts down or the
idle shutdown timer is reset. This feature shuts down
Customer programmable parameters within the ECM
the engine, but the vehicle electrical system and
provide in-cab engine speed control related options
accessories will remain active until the key switch is
that can be adjusted to suit the customer’s needs.
turned off.
Choosing whether the operator is allowed to increase
the engine speed using the accelerator pedal without
disengaging the PTO is one example.
Progressive Shift
The progressive shift feature is designed to limit the
Power Take Off (PTO) – Remote
engine speed to encourage the driver to upshift early,
which in turn improves fuel economy. This feature
When control over engine speed is required from
provides engine speed limit parameters optimized for
outside the vehicle’s cab, remote mounted switches
each transmission gear, to encourage the use of the
must be used to turn on PTO engine speed control and
higher gears during cruise control and low engine load
select the desired engine speed. This functionality is
operations.
referred to as Remote Engine Speed Control (RESC).
The engine speed can be ramped up and down with
Customer programmable parameters within the ECM
RESC similar to the way the in cab PTO feature works;
provide progressive shift related options that can be
however, the RESC feature includes two additional
adjusted to suit the customer’s needs.
switches (remote preset & remote variable), which
allow the operator to choose the mode of engine
Power Take Off (PTO) – In Cab
speed control operation.
The engine speed control feature, commonly referred
Customer programmable parameters within the ECM
to as “PTO”, provides a method for an operator to
provide RESC related options that can be adjusted
set and maintain a constant engine speed without
to suit the customer’s needs. Choosing whether a
using the accelerator pedal. It is commonly used for
remote throttle pedal is used for PTO operation is one
powering auxiliary devices.
example.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

58
2 ENGINE AND VEHICLE FEATURES
Service Interval
Upshift Indicator
The service interval feature is designed to provide
The upshift indicator feature provides an indication to
a visual reminder to the operator of service interval
the operator that the transmission should be shifted
information such as, oil change interval has expired,
into a higher gear. This helps to maintain the engine’s
and that routine maintenance procedures should be
most efficient speed range for fuel economy.
performed. The term “interval” in this case is used
The feature is commonly used on manual
to describe the distance, time, or fuel used between
transmissions and automated manuals in manual
the last maintenance performed on the vehicle and the
mode.
next maintenance, which is due.
Customer programmable parameters within the
ECM provide options that can be adjusted to suit
Road Speed Limiter
the customer’s needs. For example, the engine
Road Speed Limiter (RSL) is a feature with customer
hours, fuel used, and vehicle distance can be used
programmable parameters designed to regulate
individually or in combination to determine the service
the maximum vehicle speed as controlled by the
interval.
accelerator pedal.
It is essential that operators are trained to know the
The following additional features are available with
maintenance schedules and instructions regarding
RSL:
the operation and reset functionality of the service
interval for the feature to be effective. Refer to
•
Adjustable RSL: Provides a customer
Integral Digital Display in Section 3 – Instruments,
programmable secondary vehicle speed
Indicators, and Switches of the MaxxForce®
15
limit, lower than the limit provided by RSL, useful
Engine Operation and Maintenance Manual for more
for spreader applications and construction, etc.
information.
•
RSL Override: Raises the vehicle speed limit
provided by the RSL feature to a customer
programmable speed when the driver identifies a
Traction Control
“passing situation.”
Traction control is a system that identifies when a
•
RSL Anti-Tampering:
Customer selectable
wheel is spinning faster than the other wheels during
option, which checks whether the vehicle speed
acceleration.
signal (VSS) input is valid or if it has been subject
When a traction control condition occurs, a datalink
to tampering.
message is sent to the ECM to limit fuel for the
These options can be enabled by programmable
purpose of reducing engine torque.
parameters within the ECM.
Vehicles must have a transmission and an Antilock
Brake System (ABS) that supports traction control.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

3 DIAGNOSTIC SOFTWARE OPERATION
59
Table of Contents
Connecting EST With ServiceMaxx™ Software to MaxxForce® Engine
61
Session Files
61
ECM Programmable Features
61
Diagnostic Trouble Codes (DTCs)
62
Service Bay Tests
63
Engine Off Tests
63
Actuator Test
63
Continuous Monitor Test
63
Relative Compression Test
63
Engine Running Tests
64
Coolant Valve Test
64
Air Management Test
64
High-pressure Pump Test
64
Cylinder Cutout Test
65
Onboard Filter Cleanliness Test
65
Service Tool Procedures
66
Engine Off Procedures
66
O2 Sensor Calibration
66
Injection Quantity Adjustment
66
DPF Servicing
66
Engine Running Procedures
66
Engine Fan
66
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

60
3 DIAGNOSTIC SOFTWARE OPERATION
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

3 DIAGNOSTIC SOFTWARE OPERATION
61
Connecting EST With ServiceMaxx™
own session and save or load it at anytime. See the
ServiceMaxx™ Users Guide for details.
Software to MaxxForce® Engine
ServiceMaxx™ software also has the following added
To connect an Electronic Service Tool (EST) with
sessions:
ServiceMaxx™ software to a MaxxForce® engine,
a RP1210A or RP1210B compliant cable must be
•
Hard Start No Start
connected between the EST and vehicle Diagnostic
•
Performance
Connector. The Diagnostic Connector is located
inside the cab, above the clutch pedal.
•
Programming
These added sessions do not load automatically but
can be selected from the Sessions drop-down menu.
They are available to help diagnose common systems
Session Files
and program special features.
A Session file is a window into the Engine Control
Module (ECM). Sessions can display vehicle and
engine information, such as module calibration,
sensor signals, and actuator command signals.
ECM Programmable Features
Special engine and vehicle features can also be
Many features can be programmed into the
programmed using these sessions.
Engine Control Module (ECM) to fit many different
ServiceMaxx™ software has many default sessions
applications. To make programming changes using
that load automatically when running any Service Bay
ServiceMaxx™ software, load the Programming
Test or Service Tool Procedure. Users are not limited
session. See the ServiceMaxx™ Users Guide for
to any default session. Users are able to build their
further details.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

62
3 DIAGNOSTIC SOFTWARE OPERATION
Diagnostic Trouble Codes (DTCs)
Active (Type)
NOTE: 2010 and up model year vehicles no longer
Active DTCs are codes that are currently active.
utilize Diagnostic Trouble Code (DTC) identification
by number. DTCs are now identified using the
Previously Active (Type)
Suspect Parameter Number (SPN) and Failure Mode
Previously Active DTCs are historical codes that may
Indicator (FMI) identifiers only. These two identifiers
be caused by intermittent signals or an operating
are displayed in the DTC Window.
condition that is not currently present.
Healing (Type)
Healing DTCs can deactivate the Malfunction
Indicator Lamp (MIL) if the monitoring system does
not detect any malfunctions that would activate the
MIL for three consecutive drive cycles.
Freeze Frame Data
Figure 32
DTC window
Freeze Frame Data is a snapshot of all influencing
1.
DTC column (pre-2010)
signals at the time the DTC was set. This can help
2.
SPN column
diagnose hard-to-duplicate failures. Freeze Frame
3.
FMI column
Data is cleared as soon as the DTC is cleared.
4.
Type column
5.
Freeze Frame column
Message
6.
Message column
7.
Refresh DTC/Vehicle Events button
The Message column displays a description of the
8.
Clear DTCs button
condition causing the DTC.
Refresh DTC/Vehicle Events
Suspect Parameter Number (SPN)
The Refresh DTC/Vehicle Events button is used to
SPN identifies the individual component causing the
ensure active and previously active DTCs do not
DTC.
return after they are cleared.
Failure Mode Indicator (FMI)
Clear DTCs
FMI identifies the fault or condition affecting
the
The Clear DTCs button is used to remove active,
individual component.
previously active, and pending DTCs from the display
window.
Pending (Type)
Pending DTCs are possible emission codes detected
on the first drive cycle.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

3 DIAGNOSTIC SOFTWARE OPERATION
63
Service Bay Tests
Engine Off Tests
Engine Off Tests can be selected from the Tests
drop-down menu, under Engine Off Tests.
Figure 35
Continuous Monitor Test
Relative Compression Test
Figure 33
ServiceMaxx™ Software Tests Menu –
The Relative Compression Test measures cylinder
Engine Off Tests
balance based on the compression stroke of each
cylinder.
This test determines cylinder integrity. The ECM
Actuator Test
measures the time it takes for each piston to travel
The Actuator Test enables the user to cycle any
upward during the compression stroke. Timing is
selected actuator high or low and, if available,
based on information from the Camshaft Position
command any given duty cycle percent. While
(CMP) sensor and Crankshaft Position (CKP) sensor.
an actuator is commanded, a technician can visually
A cylinder with low compression allows the piston to
monitor actuator movement or use a Digital Multimeter
travel faster during the compression stroke.
(DMM) to measure changes in voltage or duty cycle.
Test results are displayed by numerical text or
graphical display. Assuming there are no mechanical
problems with the engine, the numbers or graphs
displayed should be approximately the same value or
height. A smaller number or lower-level graph would
indicate a problem with that particular cylinder.
NOTE: The Relative Compression Test must be run
before running the Cylinder Cutout Test.
Figure 34
Actuator Test
Continuous Monitor Test
The Continuous Monitor Test helps detect intermittent
circuit faults. During this test, signals are continuously
monitored and faults are immediately logged. A
Figure 36
Relative Compression Test
graphical view of all signals is provided, allowing
for easy detection of intermittent signal spiking or
momentary loss of signal. Perform this test while
manipulating connectors, wiring, and harnesses of
the suspected faulty component.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

64
3 DIAGNOSTIC SOFTWARE OPERATION
Engine Running Tests
Air Management Test
Engine Running Tests can be selected from the Tests
The Air Management Test validates performance of
drop-down menu, under Engine Running Tests.
the Air Management System (AMS) by monitoring
the effects each actuator has on the Intake Manifold
Pressure (IMP) sensor.
Figure 37
ServiceMaxx™ Software Tests Menu –
Engine Running Tests
Coolant Valve Test
Figure 39
Air Management Test
The Coolant Valve Test actuates the Coolant Flow
Valve (CFV) and Coolant Mixer Valve (CMV) for 5
High-pressure Pump Test
seconds at a time during the test. This test is used
to verify the CFV and CMV are operating correctly, as
The High-pressure Pump Test validates performance
well as to validate the performance of the interstage
of the Fuel Rail Pressure
(FRP) system. This
cooler.
test commands the Fuel Pressure Control Valve
(FPCV) high and low at four different set points while
monitoring the FRP sensor. The time it takes for
pressure to build and drop determines if system is
performing within specification.
Figure 38
Coolant Valve Test
Figure 40
High-pressure Pump Test
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

3 DIAGNOSTIC SOFTWARE OPERATION
65
Cylinder Cutout Test
Onboard Filter Cleanliness Test
The Cylinder Cutout Test isolates a low contributing
The Onboard Filter Cleanliness Test performs a
cylinder due to an injector circuit fault.
parked regeneration (regen) and increases engine
speed to measure pressure differential across the
Before starting the Cylinder Cutout Test, follow the
Diesel Particulate Filter (DPF). This test can be run
steps below:
at any time.
1. Run Relative Compression Test.
•
If Relative Compression Test results
indicate low balanced cylinder(s), there is
no need to run the Cylinder Cutout Test.
Repair mechanical fault.
2. Verify fuel system pressure is not below
specification and fuel is not aerated.
Figure 42
Onboard Filter Cleanliness Test
Figure 41
Cylinder Cutout Test
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

66
3 DIAGNOSTIC SOFTWARE OPERATION
Service Tool Procedures
IQA injects the correct amount of fuel for each
individual injector throughout the operating range of
Service tool procedures are special ECM controls
the engine. Injector mechanical tolerances, high flow,
that allow the user to perform specific procedures.
and low flow can be evenly balanced with the ECM
MaxxForce®
15
engines have four special
calibration.
procedures: O2 Sensor Calibration, Injector Quantity
Adjustment (IQA), DPF Servicing, and Engine Fan.
Follow on-screen instructions when running service
DPF Servicing
tool procedures.
The DPF Servicing procedure is used to update the
installation date and serial number (if replaced) of
Engine Off Procedures
the Diesel Particulate Filter (DPF). This procedure
should be run any time the DPF has been replaced or
Engine Off Procedures can be selected from the
removed for cleaning.
Procedures drop-down menu.
Engine Running Procedures
Engine Running Procedures can be selected from the
Procedures drop-down menu.
Figure 43
ServiceMaxx™ Software Procedures
Menu – Engine Off Procedures
O2 Sensor Calibration
The Oxygen Sensor Calibration procedure calibrates
Figure 44
ServiceMaxx™ Software Procedures
the Oxygen Sensor
(O2S). Anytime the O2S is
Menu – Engine Running Procedures
replaced, this procedure needs to be performed.
Engine Fan
Injection Quantity Adjustment
The Engine Fan procedure turns the engine fan OFF
The Injection Quantity Adjustment (IQA) procedure
and ON while the engine is running to help diagnose
is used to calibrate new injectors. Each injector is
fan failures.
encrypted with an IQA code that must be programmed
into the ECM anytime an injector has been replaced.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

4 ENGINE SYMPTOMS DIAGNOSTICS
67
Table of Contents
Coolant System
69
Coolant System Components
69
Coolant Loss
70
Coolant Overflow
72
Coolant Leak to Exhaust
73
Coolant Leak to Fuel
75
Coolant Leak to Intake
77
Coolant Leak to Lube Oil
78
Coolant Over-Temperature
80
Lubrication System
83
Incorrect Oil Level
83
Dilution From Coolant
83
Dilution From Fuel
83
Power Steering Fluid Leak to Lube Oil
83
Lube Oil to Coolant
84
Lube Oil to Intake
84
Lube Oil to Exhaust
84
Low Oil Pressure
85
Fuel System
88
Excessive Fuel Consumption
88
Fuel in Coolant
89
Fuel in Lube Oil
91
Fuel to Intake
92
Fuel to Exhaust
93
Compression to Fuel
93
Fuel Pressure and Aeration
94
Water in Fuel
94
Fuel System Priming
95
Engine Brake System
96
Engine Brake Inspection
96
Brake Piston Lash Adjustment Procedure
99
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

68
4 ENGINE SYMPTOMS DIAGNOSTICS
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

4 ENGINE SYMPTOMS DIAGNOSTICS
69
Coolant System
Coolant System Components
Figure 45
Coolant System Components
1.
Exhaust Gas Recirculation
4.
EGR coolant tube assembly
9.
Coolant Control Valve (CCV)
(EGR) coolant tube assembly
(secondary EGR cooler)
assembly (Coolant Mixer Valve
(primary EGR cooler)
5.
Engine Coolant Temperature
[CMV] and Coolant Flow Valve
2.
EGR coolant return (secondary
1
(ECT1) sensor (behind
[CFV])
EGR cooler)
Interstage Cooler)
10. Coolant adapter
3.
EGR coolant return (primary
6.
Thermostat housing cover
11. Engine Coolant Pressure (ECP)
EGR cooler)
7.
Water pump
sensor
8.
Water pump inlet
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

70
4 ENGINE SYMPTOMS DIAGNOSTICS
Coolant Loss
•
Failed Aftertreatment Fuel Injector (AFI)
•
Failed Coolant Control Valve (CCV)
•
Failed Low Temperature Radiator (LTR)
GOVERNMENT REGULATION: Engine
•
Failed air compressor
fluids (oil, fuel, and coolant) may be a hazard
to human health and the environment. Handle
•
Failed Interstage Cooler (ISC)
all fluids and other contaminated materials
•
Failed EGR cooler
(e.g., filters rags) in accordance with applicable
regulations.
Recycle or dispose of engine
•
Damaged or failed distributor housing
fluids, filters, and other contaminated materials
•
Failed oil cooler
according to applicable regulations.
•
Cracked cylinder head
•
Porous or cracked cylinder liner
WARNING: To prevent personal injury or death,
•
Cylinder liner O-ring leak
read all safety instructions in the “Safety Information”
section of this manual.
Tools
•
ZTSE2384 – Radiator Pressure Testing Kit
WARNING: To prevent personal injury or death,
shift transmission to park or neutral, set parking brake,
•
ZTSE6090 – EGR Cooler Pressure Test Kit
and block wheels before doing diagnostic or service
procedures.
Procedure
1. Check engine service records to determine the
WARNING: To prevent personal injury or
frequency and quantity of coolant added.
death, do not let engine fluids stay on your skin.
•
If the vehicle’s coolant system is being
Clean skin and nails using hand cleaner and wash
overfilled, there will be a small coolant loss
with soap and water. Wash or discard clothing and
everyday. Educate driver on correct coolant
rags contaminated with engine fluids.
level.
Symptom
•
If coolant system maintenance is correct,
continue to next step.
Consistent need to refill deaeration tank and active
or previously active Diagnostic Trouble Codes (DTCs)
NOTE: Ensure engine oil and coolant are within
related to the coolant system.
normal operating ranges and there is no coolant
on the oil level gauge (dipstick), before running the
Possible Causes
engine.
•
External leaks
2. Start engine.
With engine at operating
•
Improper servicing
temperature and operating at high idle speed,
inspect for coolant overflow.
•
Loose or failed coolant hoses
•
If coolant overflow is detected, go to Coolant
•
Damaged or failed deaeration cap
Overflow (page 72).
•
Damaged or failed deaeration tank
•
If coolant overflow is not detected, continue to
•
Damaged or failed radiator
next step.
•
Damaged or failed heater core
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

4 ENGINE SYMPTOMS DIAGNOSTICS
71
6. Visually inspect all components and hoses for
WARNING: To prevent personal injury or death,
external coolant leaks.
wear safety glasses with side shields.
•
If an external coolant leak is found, repair as
necessary. Retest coolant system.
WARNING: To prevent personal injury or death,
•
If no external coolant leak is found, continue
do the following when removing the radiator cap or
to next step.
deaeration cap:
•
Allow the engine to cool for 15 minutes or more.
WARNING: To prevent personal injury or death,
•
Wrap a thick cloth around the radiator cap or
do not smoke or park vehicle near open flames or
deaeration cap.
sparks when taking a fuel sample.
•
Loosen cap slowly a quarter to half turn to vent
7.
Obtain a fuel sample from fuel tank. Test fuel
pressure.
sample for coolant contamination.
•
Pause for a moment until all pressure has
•
If fuel sample is contaminated with coolant, go
escaped to avoid being scalded by steam.
to Coolant Leak to Fuel (page 75).
•
Continue to turn cap counterclockwise to remove.
•
If fuel sample is not contaminated with
coolant, continue to next step.
3.
Remove deaeration tank cap. Check sealing
surfaces of deaeration cap and deaeration tank
8.
Inspect intake manifold, Interstage Cooler (ISC)
for damage.
outlet, and EGR cooler for coolant.
•
If sealing surfaces are damaged, install new
•
If there is coolant in the intake manifold, ISC
components as necessary. Retest coolant
outlet, or EGR cooler, go to Coolant Leak to
system.
Intake (page 77).
•
If sealing surfaces are not damaged, continue
NOTE: The EGR cooler can be inspected by
to next step.
removing the cold side tubes at the intake.
4.
Connect Radiator Pressure Testing Kit to
•
If there is no coolant in the intake manifold,
deaeration cap. Pressurize deaeration cap to
ISC outlet, or EGR cooler, continue to next
its rated pressure.
step.
•
If deaeration cap does not hold the rated
9.
Obtain an oil sample from engine. Test oil sample
pressure, install a new deaeration cap.
for coolant contamination.
Retest coolant system.
•
If oil sample is contaminated with coolant, go
•
If deaeration cap holds the rated pressure,
to Coolant Leak to Lube Oil (page 78).
continue to next step.
•
If oil sample is not contaminated with coolant,
5.
Connect Radiator Pressure Testing Kit to
go to Coolant Leak to Exhaust (page 73).
deaeration tank.
Pressurize coolant system
to 103 kPa (15 psi) for 15 minutes.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

72
4 ENGINE SYMPTOMS DIAGNOSTICS
Coolant Overflow
Coolant Overflow Test
Symptom
WARNING: To prevent personal injury or death,
wear safety glasses with side shields.
Coolant flowing or bubbling from the deaeration tank.
Possible Causes
WARNING: To prevent personal injury or death,
•
Failed air compressor
do the following when removing the radiator cap or
deaeration cap:
•
Failed ISC
•
Allow the engine to cool for 15 minutes or more.
•
Failed EGR cooler
•
Wrap a thick cloth around the radiator cap or
•
Failed cylinder head gasket
deaeration cap.
•
Cracked cylinder liner
•
Loosen cap slowly a quarter to half turn to vent
•
Cracked cylinder head
pressure.
•
Failed oil cooler
•
Pause for a moment until all pressure has
escaped to avoid being scalded by steam.
Tools
•
Continue to turn cap counterclockwise to remove.
•
Hose pinch-off pliers (2)
1.
Remove deaeration tank cap.
•
ZTSE2384 – Radiator Pressure Testing Kit
2.
Connect Radiator Pressure Testing Kit to
•
ZTSE6042 – Interstage Cooler Test Kit
deaeration tank.
•
ZTSE6090 – EGR Cooler Pressure Testing Kit
3.
Pressurize coolant system to 103 kPa (15 psi) for
15 minutes.
Air Compressor Leak Test
4.
Inspect the intake manifold and ISC outlet for
coolant.
1. Partially drain coolant system.
•
If there is coolant in the intake manifold or ISC
2. Using hose pinch-off pliers, clamp off both coolant
outlet, go to Coolant Leak to Intake (page 77).
lines between air compressor and engine block.
•
If there is no coolant in the intake manifold, but
3. Refill coolant system to proper operating level.
coolant is found in the ISC outlet, continue to
CAUTION: To prevent engine damage, do not run the
next test.
engine for more than one minute. This can overheat
•
If there is no coolant in the intake manifold or
the air compressor.
ISC outlet, go to EGR Cooler Leak Inspection
4. Start and run engine for a maximum of one
(page 73).
minute.
•
If
coolant continues overflowing from
deaeration tank, continue to next test.
•
If coolant stops overflowing from deaeration
tank, install a new air compressor following
procedures in the Engine Service Manual.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

4 ENGINE SYMPTOMS DIAGNOSTICS
73
Interstage Cooler (ISC) Leak Test
Coolant Leak to Exhaust
1. Completely drain engine coolant.
Symptoms
Coolant leaks to the exhaust may be detected
WARNING: To prevent personal injury or death,
externally or internally.
See the following list
wear safety glasses with side shields.
of symptoms for identification of coolant leaks to
2. Pressure test the ISC following procedures in the
exhaust:
Engine Service Manual.
•
Coolant residue at exhaust manifold flanges
3. Monitor air pressure in ISC for five minutes.
•
Observation of coolant loss without engine
•
If ISC does not hold pressure, replace the ISC
overheating
following procedures in the Engine Service
•
Coolant smell in exhaust
Manual.
•
Coolant leaking from exhaust
•
If ISC holds pressure, continue to next test.
•
Engine hydraulic lock (severe cases only)
•
Plugged Diesel Particulate Filter (DPF) or Diesel
Exhaust Gas Recirculation (EGR) Cooler Leak
Oxidation Catalyst (DOC)
Inspection
Possible Causes
1. Visually inspect EGR cooler for external cracks or
leaks.
•
Failed EGR cooler
•
If an external leak or crack is found, replace
•
Failed AFI
EGR cooler following procedures in the
•
Cracked cylinder head
Engine Service Manual and retest.
•
Cracked cylinder liner
•
If no external leaks or cracks are found,
continue to next step.
NOTE: If a coolant leak to exhaust is determined from
one of the listed possible causes, the Oxygen Sensor
(O2S) must be replaced. See the Engine Service
WARNING: To prevent personal injury or death,
Manual for O2S replacement procedures. Perform
wear safety glasses with side shields.
O2S Calibration Procedure (page 348) anytime O2S
2. Pressure test EGR cooler, in vehicle, following
is replaced.
procedures in the Engine Service Manual.
Tools
•
If no leaks are found, go to Coolant Leak to
•
ZTSE2384 – Radiator Pressure Testing Kit
Lube Oil (page 78).
•
ZTSE6090 – EGR Cooler Pressure Testing Kit
•
If a leak is found, replace EGR cooler
following procedures in the Engine Service
Manual.
•
If EGR cooler is leaking coolant internally,
replace Oxygen Sensor
(O2S) following
procedures in the
html after text
html before text

DIAGNOSTIC/TROUBLESHOOTING MANUAL
DIAGNOSTIC/TROUBLESHOOTING MANUAL
MaxxForce® 15 Engine Diagnostic Manual
Engine Family: MaxxForce® 15
EGES-515-1
2012
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.


DIAGNOSTIC/TROUBLESHOOTING MANUAL
I
Table of Contents
Foreword
1
Service Diagnosis
2
Safety Information
3
Engine Systems
5
Engine and Vehicle Features
51
Diagnostic Software Operation
59
Engine Symptoms Diagnostics
67
Hard Start and No Start Diagnostics
101
Performance Diagnostics
135
Electronic Control Systems Diagnostics
171
Diagnostic Tools and Accessories
375
Abbreviations and Acronyms
401
Terminology
409
Appendix A: Performance Specifications
421
Appendix B: Signal Values
433
Appendix C: Technical Service Information (TSI)
443
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

II
DIAGNOSTIC/TROUBLESHOOTING MANUAL
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

DIAGNOSTIC/TROUBLESHOOTING MANUAL
1
Foreword
Technical Service Literature
Navistar, Inc. is committed to continuous research
1172042R1
MaxxForce® 15 Engine Operation
and development to improve products and introduce
and Maintenance Manual
technological advances. Procedures, specifications,
EGES-510-2
MaxxForce® 15 Engine Service
and parts defined in published technical service
Manual
literature may be altered.
EGES-515-1
MaxxForce® 15 Engine Diagnostic
NOTE: Photo illustrations identify specific parts or
manual
assemblies that support text and procedures; other
EGED-520-1
MaxxForce® 15 Hard Start and
areas in a photo illustration may not be exact.
No Start Diagnostics Form
This manual includes necessary information and
EGED-535-1
MaxxForce® 15 Performance
specifications for technicians to maintain Navistar®
Diagnostics Form
diesel engines. See vehicle manuals and Technical
Service Information
(TSI) bulletins for additional
EGED-525-1
MaxxForce® 15 Engine Wiring
information.
Diagram Form
Technical Service Literature is revised periodically
and mailed automatically to
“Revision Service”
subscribers. If a technical publication is ordered, the
latest revision will be supplied.
NOTE: To order technical service literature, contact
your International dealer.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

2
DIAGNOSTIC/TROUBLESHOOTING MANUAL
Service Diagnosis
•
Knowledge of the principles of operation for
engine application and engine systems
Service diagnosis is an investigative procedure that
must be followed to find and correct an engine
•
Knowledge to understand and do procedures in
application problem or an engine problem.
diagnostic and service publications
If the problem is engine application, see specific
Technical Service Literature required for Effective
vehicle manuals for further diagnostic information.
Diagnosis
If the problem is the engine, see specific Engine
•
Engine Service Manual
Diagnostic Manual for further diagnostic information.
•
Engine Diagnostic Manual
Prerequisites for Effective Diagnosis
•
Diagnostics Forms
•
Availability of gauges and diagnostic test
•
Electronic Control Systems Diagnostics Forms
equipment
•
Service Bulletins
•
Availability of current information for engine
application and engine systems
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

DIAGNOSTIC/TROUBLESHOOTING MANUAL
3
Safety Information
•
Restrain long hair.
Vehicle
This manual provides general and specific
maintenance procedures essential for reliable engine
•
Make sure the vehicle is in neutral, the parking
operation and your safety. Since many variations in
brake is set, and the wheels are blocked before
procedures, tools, and service parts are involved,
servicing engine.
advice for all possible safety conditions and hazards
•
Clear the area before starting the engine.
cannot be stated.
Engine
Read safety instructions before doing any service and
test procedures for the engine or vehicle. See related
•
The engine should be operated or serviced only
application manuals for more information.
by qualified individuals.
Disregard for Safety Instructions, Warnings, Cautions,
•
Provide necessary ventilation when operating
and Notes in this manual can lead to injury, death or
engine in a closed area.
damage to the engine or vehicle.
•
Keep combustible material away from engine
exhaust system and exhaust manifolds.
Safety Terminology
•
Install all shields, guards, and access covers
Three terms are used to stress your safety and safe
before operating engine.
operation of the engine: Warning, Caution, and Note
•
Do not run engine with unprotected air inlets or
Warning: A warning describes actions necessary to
exhaust openings. If unavoidable for service
prevent or eliminate conditions, hazards, and unsafe
reasons, put protective screens over all openings
practices that can cause personal injury or death.
before servicing engine.
Caution: A caution describes actions necessary
•
Shut engine off and relieve all pressure in the
to prevent or eliminate conditions that can cause
system before removing panels, housing covers,
damage to the engine or vehicle.
and caps.
Note: A note describes actions necessary for correct,
•
If an engine is not safe to operate, tag the engine
efficient engine operation.
and ignition key.
Safety Instructions
Fire Prevention
Work Area
•
Make sure charged fire extinguishers are in the
work area.
•
Keep work area clean, dry, and organized.
NOTE: Check the classification of each fire
•
Keep tools and parts off the floor.
extinguisher to ensure that the following fire types
•
Make sure the work area is ventilated and well lit.
can be extinguished.
•
Make sure a First Aid Kit is available.
1. Type A — Wood, paper, textiles, and rubbish
Safety Equipment
2. Type B — Flammable liquids
•
Use correct lifting devices.
3. Type C — Electrical equipment
•
Use safety blocks and stands.
Batteries
Protective Measures
•
Always disconnect the main negative battery
cable first.
•
Wear protective safety glasses and shoes.
•
Always connect the main negative battery cable
•
Wear correct hearing protection.
last.
•
Wear cotton work clothing.
•
Avoid leaning over batteries.
•
Wear sleeved heat protective gloves.
•
Protect your eyes.
•
Do not wear rings, watches or other jewelry.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

4
DIAGNOSTIC/TROUBLESHOOTING MANUAL
•
Do not expose batteries to open flames or sparks.
•
Check for frayed power cords before using power
tools.
•
Do not smoke in workplace.
Fluids Under Pressure
Compressed Air
•
Use extreme caution when working on systems
•
Use an OSHA approved blow gun rated at 207
under pressure.
kPa (30 psi).
•
Follow approved procedures only.
•
Limit shop air pressure to 207 kPa (30 psi).
Fuel
•
Wear safety glasses or goggles.
•
Do not over fill the fuel tank. Over fill creates a fire
•
Wear hearing protection.
hazard.
•
Use shielding to protect others in the work area.
•
Do not smoke in the work area.
•
Do not direct compressed air at body or clothing.
•
Do not refuel the tank when the engine is running.
Tools
Removal of Tools, Parts, and Equipment
•
Make sure all tools are in good condition.
•
Reinstall all safety guards, shields, and covers
•
Make sure all standard electrical tools are
after servicing the engine.
grounded.
•
Make sure all tools, parts, and service equipment
are removed from the engine and vehicle after all
work is done.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
5
Table of Contents
Engine Identification
7
Engine Serial Number
7
Engine Emission Label
7
Engine Accessory Labels and Identification Plates
8
Engine Specifications
9
Engine Description
9
Optional Features
10
Chassis Mounted Features
10
Engine Component Locations
11
Air Management System (AMS)
16
Air Flow
16
Air Management Components
17
Turbochargers
17
Interstage Cooler (ISC)
18
High-Pressure Charge Air Cooler (HPCAC)
19
Air Control Valve
19
Exhaust Gas Recirculation (EGR) System
20
Aftertreatment (AFT) System
22
Aftertreatment Fuel Injection Components
24
Fuel Management System
26
Chassis Mounted Components
27
Engine Mounted Components
29
Engine Lubrication System
31
Oil Flow and Components
32
Engine Cooling System
34
Cooling System Components
34
Cooling System Flow
35
Thermostat Operation
36
Coolant Control Valve (CCV) Assembly Operation
36
MaxxForce®Engine Brake System
38
Engine Brake System Components
38
Engine Brake Operation
39
Open Crankcase Breather System
40
Open Crankcase Breather System Components
40
Open Crankcase Breather System Operation
41
Cold Start Assist System
42
Cold Start Assist System Operation
43
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

6
1 ENGINE SYSTEMS
Electronic Control System
44
Electronic Control System Components
44
Operation and Function
44
Reference Voltage (VREF)
44
Signal Conditioner
44
Microprocessor
44
Diagnostic Trouble Codes
44
Microprocessor Memory
44
Actuator Control
45
Actuators
45
Coolant Flow Valve and Coolant Mixer Valve
45
Exhaust Gas Recirculation (EGR) Valve Assembly
45
Air Control Valve
45
Cold Start Relay (CSR)
45
Cold Start Fuel Solenoid (CSFS)
45
Engine Throttle Valve (ETV)
46
Fuel Pressure Control Valve (FPCV)
46
Engine and Vehicle Sensors
46
Thermistor Sensor
46
Variable Resistance Sensor
47
Magnetic Pickup Sensor
48
Potentiometer
49
Switches
49
Oxygen Sensor (O2S)
50
Turbocharger 2 Compressor Inlet Sensor (TC2CIS)
50
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
7
Engine Identification
Engine Emission Label
Engine Serial Number
Figure 1
Engine serial number location
The engine serial number is located on the lower left
side of the crankcase above the oil pan flange.
Engine Serial Number Example
Figure 2
U.S. Environmental Protection Agency
(EPA) exhaust emission label (example)
152HM2YXXXXXXX
Engine Serial Number Codes
The U.S. Environmental Protection Agency (EPA)
15.2 – Engine displacement
exhaust emission label is on top of the valve cover
H – Diesel, turbocharged, Charge Air Cooler (CAC)
(front left side). The EPA label typically includes the
and electronically controlled
following:
M2 – Motor truck
•
Model year
Y – United States, Huntsville
7 digit suffix – Engine serial number sequence
•
Engine family, model, and displacement
•
Advertised brake horsepower and torque rating
•
Emission family and control systems
•
Valve lash specifications
•
Engine serial number
•
EPA, EURO, OBD and reserved fields for specific
applications
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

8
1 ENGINE SYSTEMS
Engine Accessory Labels and Identification Plates
•
Cooling fan clutch
The following engine accessories may have
•
High-pressure fuel pump
manufacturer’s labels or identification plates:
•
Power steering pump
•
Air compressor
•
Starter motor
•
Air conditioning compressor
•
Turbochargers
•
Alternator
•
Engine Control Module (ECM)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
9
Engine Specifications
MaxxForce® 15 Diesel Engine
Engine Configuration
4 stroke, inline six cylinder diesel
Advertised brake horsepower @ rpm
See EPA exhaust emission label
Peak torque @ rpm
See EPA exhaust emission label
Displacement
15.2 L (928 in3)
Compression ratio
16.0:1
Stroke
171.5 mm (6.75 in)
Bore (sleeve diameter)
137.2 mm (5.40 in)
Engine weight (dry, without trim or accessories)
1 429 kg (3,150 lbs)
Firing order
1-5-3-6-2-4
Engine rotation (facing flywheel)
Counterclockwise
Aspiration
Dual turbocharged and Charge Air
Cooled (CAC)
Combustion system
Direct injection turbocharged
Fuel system
High-pressure common rail
Lube system refill capacity (including filter)
•
Gravity drain from right rear and bottom front sump plugs
38 L (40 qts)
•
Suction oil recovery option
34.5 L (36.5 qts)
Engine lubrication oil pressure at 99°C (210°F)
•
600 rpm
Minimum 83 kPa (12 psi)
•
1,600 rpm
275 – 550 kPa (40 – 80 psi)
Idle speed (no load)
600 rpm, nominal
Thermostat transition range (start open — full open)
88°C – 103°C (190°F – 217°F)
Engine Description
The MaxxForce® 15 engine uses one piece forged
steel pistons. Cooling jet cutouts and feed holes are
The MaxxForce® 15 diesel engine has been designed
placed on both sides of the pistons. Pistons may
for increased durability and reliability.
be installed in either direction however pistons are
The cylinder head has four valves per cylinder with
originally installed with casting bump on bottom of pin
centrally located fuel injectors directing fuel over
boss toward rear of engine.
the pistons. This configuration provides improved
The one piece crankcase can withstand high-pressure
performance and reduces emissions.
loads during operation.
The crankcase uses
The overhead camshaft is supported by seven
replaceable wet cylinder sleeves that are sealed
bearings in the cylinder head. The camshaft gear is
by a system of three O-rings.
driven from the front of the engine. The overhead
Sound shields are strategically placed on the engine
valve train includes roller rocker arms and dual valves
to reduce noise.
that open using a valve bridge.
The crankshaft has seven main bearings with fore
and aft thrust controlled at the forth bearing. One
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

10
1 ENGINE SYSTEMS
connecting rod is attached at each crankshaft journal.
The engine brake is standard on the MaxxForce® 15.
The piston pin moves freely inside the connecting rod
The engine brake is a compression release system
and piston. Piston pin retaining rings secure the piston
that provides additional vehicle braking performance.
pin in the piston. The rear oil seal carrier is part of the
The operator can control the engine brake for different
flywheel housing, and the front oil seal carrier is part
operating conditions.
of the front cover.
An oil pump is mounted within the oil pan to the
Optional Features
bottom of the crankcase behind the front cover and is
driven by the crankshaft. Pressurized oil is supplied to
An oil pan heater and a coolant heater are available
internal engine components, air compressor, power
as optional cold climate features. Both heaters use an
steering pump and turbochargers. All MaxxForce®
electric element to warm engine fluids in cold weather
15 engines use an engine oil cooler and a spin-on
conditions.
can style engine oil filter element.
The oil pan heater warms engine oil to ensure
Fuel is drawn from the fuel tank through the
optimum oil flow to engine components.
frame-mounted fuel/water filter separator. A hand
The coolant heater warms the engine coolant
operated primer pump is located either on top of
surrounding the cylinders. Warmed engine coolant
or next to the frame-mounted fuel/water separator.
increases fuel economy and aids start-up in cold
The fuel is then routed into the fuel pump and to the
weather conditions.
engine-mounted fuel filter. Conditioned fuel is then
pumped to the fuel injectors.
The fuel injection system is direct common rail. The
Chassis Mounted Features
system includes a high-pressure fuel pump, fuel rail
The aftertreatment system, part of the larger
and fuel injectors. The injectors are installed in the
exhaust system, processes engine exhaust so that
cylinder head under the valve cover.
it meets tailpipe emission requirements. Most of the
The MaxxForce® 15 engine uses dual turbochargers
aftertreatment system is mounted on the chassis.
with an air-to-liquid Interstage Cooler (ISC) between
•
The Pre-Diesel Oxidation Catalyst
(PDOC)
turbochargers, and a chassis-mounted air-to-air
and Diesel Oxidation Catalyst (DOC) which is
Charge Air Cooler (CAC) to reduce air temperature
mounted on the chassis, oxidizes hydrocarbons
before entering the intake.
and carbon monoxide, provides heat for exhaust
The cold start assist system warms the incoming
system warm-up, and aids in temperature
air supply before, during, and a short period after
management for the Diesel Particulate Filter
cranking to aid cold engine starting and reduce white
(DPF) for passive DPF regeneration.
smoke during warm-up.
•
The DPF temporarily stores carbon-based
The Exhaust Gas Recirculation
(EGR) system
particulates then oxidizes the particulates and
circulates cooled exhaust into the intake air stream in
stores the noncombustible ash.
the mixing duct. This cools the combustion process
The High-Pressure Charge Air Cooler
(HPCAC)
and reduces the formation of Nitrogen Oxides (NOX)
mounted on the vehicle cooling module, is connected
engine emissions. The EGR cooler assembly cools
between the outlet of the high-pressure turbocharger
the exhaust gas in two stages.
and the inlet to the engine throttle valve assembly.
An open crankcase breather system uses an oil
The HPCAC is an air-to-air cooler that uses ambient
separator to return oil to the crankcase and vent
air to cool pressurized air before it enters the engine.
the crankcase gasses to the atmosphere. The oil
separator is mounted on the cylinder head.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
11
Engine Component Locations
Figure 3
Component location – top
1.
Turbocharger interstage cooler
3.
Valve cover assembly
6.
Charge Air Cooler Outlet
assembly
4.
Exhaust gas temperature sensor
Temperature (CACOT) sensor
2.
Flywheel housing assembly
5.
Cold Start Fuel Igniter (CSFI)
7.
Breather filter assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

12
1 ENGINE SYSTEMS
Figure 4
Component location – front
1.
Water pump pulley
4.
EGR crossover tube assembly
7.
Camshaft gear cover
2.
Air inlet duct (turbocharger)
5.
Engine throttle valve assembly
8.
Low mount fan drive
3.
Front lifting eye
6.
Oil filler pipe assembly
9.
Damper (crankshaft)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
13
Figure 5
Component location – right
1.
Pre-Diesel Oxidation Catalyst
6.
Interstage cooler assembly
11. Oil filter
(PDOC) assembly
7.
High-pressure turbocharger
12. Low-Pressure (LP) turbocharger
2.
Fuel doser
compressor outlet
assembly
3.
Exhaust Gas Recirculation
8.
Oil supply tube for secondary
13. High-pressure turbocharger
(EGR) cooler assembly
filtration (to soot filter)
wastegate actuator
4.
High-Pressure (HP)
9.
Coolant inlet (from radiator)
14. Engine oil cooler assembly
turbocharger assembly
10. Coolant Control Valve (CCV)
5.
Thermostat housing
assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

14
1 ENGINE SYSTEMS
Figure 6
Component location – left
1.
Air compressor
7.
Fuel Delivery Pressure (FDP)
12. Oil pan drain plug (front sump)
2.
Oil level gauge assembly
sensor
13. Cold Start Fuel Solenoid (CSFS)
3.
Crankcase breather
8.
Fuel filter
14.
5 mm 60 degree speed sensor
4.
Engine Control Module (ECM)
9.
Oil pan drain plug (rear sump)
(crankshaft position sensor)
5.
Down Stream Injection (DSI)
10. Crankcase Pressure (CPS)
15. High-pressure fuel pump
assembly
sensor
16. Power steering pump
6.
12V relay (for cold start assist
11. Engine Oil Pressure (EOP)
solenoid)
sensor
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
15
Figure 7
Component location – rear
1.
Rear lifting eye
3.
Fuel return tube assembly
6.
Oil pan
2.
Exhaust Gas Recirculation
4.
EGR cooler supply tube
7.
Flywheel housing
(EGR) valve assembly
5.
Flywheel
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

16
1 ENGINE SYSTEMS
Air Management System (AMS)
Figure 8
Air Management System (AMS)
Air Flow
air flows into the Charge Air Cooler (CAC) where it
is cooled, and then directed to the Engine Throttle
Air flows through the air cleaner assembly and enters
Valve (ETV) and mixing duct area of the throttle valve
the low-pressure turbocharger. The low-pressure
assembly.
turbocharger increases the pressure, temperature,
and density of the intake air before it enters the
If the EGR control valve is open, exhaust gas passes
Interstage Cooler (ISC). Cooled compressed air flows
through the EGR system into the mixing duct where it
from the ISC into the high-pressure turbocharger. The
is mixed with the filtered intake air. This mixture flows
high-pressure turbocharger increases the intake air
through the mixing duct into the intake manifold and
pressure up to 345 kPa (50 psi). The hot compressed
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
17
cylinder head. The intake manifold is an integral part
Air Management Components
of the cylinder head casting.
Turbochargers
If the EGR control valve is closed, only filtered intake
The MaxxForce® 15 engine is equipped with an
air flows through the ETV, mixing duct, and into the
electronically controlled, pneumatically actuated two
intake manifold.
stage turbocharging system. This system provides
During cold weather, the Cold Start Fuel Igniter (CSFI)
high levels of charge air pressure to improve engine
rapidly heats the intake air by injecting and igniting
performance and help reduce emissions. Because of
small quantities of fuel into the mixing duct.
its ability to generate very high charge air pressure
levels, the system is fitted with an air control valve
After combustion, gases exit through the cylinder
to control over-boost and surging conditions. The
head exhaust valves and ports. The exhaust gas
air control valve is supplied compressed air from the
is forced through the exhaust manifold where,
vehicle air supply tank. The compressed air flow to
depending on the EGR valve assembly position,
the wastegate actuator is electronically controlled
is split between the EGR system and the exit
by the air control valve based on the Pulse Width
path through the high-pressure turbocharger and
Modulated
(PWM) signal supplied by the Engine
low-pressure turbocharger.
Control Module (ECM). The high and low-pressure
The exhaust gases flow from the low-pressure
turbochargers are installed as an assembly on the
turbocharger through the vehicle aftertreatment
exhaust manifold, on the right side of the engine.
system to the exhaust tail pipe.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

18
1 ENGINE SYSTEMS
Figure 9
Low and high-pressure turbocharger components
1.
Low-pressure turbocharger
6.
High-pressure turbocharger
11. High-pressure turbocharger
assembly
turbine inlet
compressor outlet
2.
High-pressure turbocharger oil
7.
Low-pressure turbocharger
12. High-pressure turbocharger
supply hose
assembly
wastegate actuator
3.
Air control valve
8.
Low-pressure turbocharger oil
13. Turbine output pressure tube
4.
High-pressure turbocharger
supply hose
14. Turbocharger oil drain tube
assembly
9.
Low-pressure turbocharger
assembly
5.
High-pressure turbocharger
compressor outlet
15. Low-pressure turbocharger
compressor inlet
10. Low-pressure turbocharger
turbine outlet
compressor inlet
The low and high-pressure turbochargers are installed
Fresh air from the air filter enters the low-pressure
in series on the right side of the engine. The
compressor where it is compressed and directed into
high-pressure turbocharger is connected directly
the Interstage Cooler (ISC). Cooled condensed air
to the exhaust manifold through the high-pressure
from the ISC enters the high-pressure compressor,
turbine inlet. The turbine input of the low-pressure
where it is further compressed and directed to the
turbocharger is connected to the turbine outlet of
High-Pressure Charge Air Cooler (HPCAC) mounted
the high-pressure turbocharger. The high-pressure
near the cooling module. Cooled and condensed air
turbocharger is equipped with a wastegate actuator
then flows directly into the engine throttle valve.
which regulates turbocharger boost by controlling
the amount of exhaust gases that pass through the
turbine. When boost demand is low, the wastegate
Interstage Cooler (ISC)
opens, allowing part of the exhaust gas flow to bypass
The ISC is installed between the low-pressure and
the turbine.
the high-pressure turbochargers. The ISC air inlet
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
19
is connected to the low-pressure compressor outlet
The air control valve controls air pressure to the
and uses engine coolant to regulate the charge air
high-pressure wastegate actuator based on turbine
temperature. The ISC air outlet is connected to the
output pressure from a port on the output of the
compressor inlet on the high-pressure turbocharger.
low-pressure turbocharger.
The turbine output
pressure sensor is integral to the air control valve. Air
pressure to the air control valve is supplied from an
High-Pressure Charge Air Cooler (HPCAC)
air tank mounted on the chassis. The air control valve
is controlled by the Engine Control Module (ECM).
The HPCAC is installed between the high-pressure
turbocharger compressor outlet and the Engine
The air control valve is normally closed. Thus, with no
Throttle Valve (ETV). The HPCAC uses ambient air
Pulse Width Modulated (PWM) signal, the air control
flow to regulate the charge air temperature. The
valve remains closed and no air pressure is supplied
HPCAC air outlet is connected to the ETV body.
to the wastegate actuator on the high-pressure
turbocharger.
When a decrease in charge air
pressure is required, the ECM supplies a PWM
Air Control Valve
ground voltage to the negative side of the wastegate
control solenoid. The other side of the wastegate
control solenoid is connected to 12V supply voltage.
This causes the air control valve to open which
supplies air pressure to the wastegate actuator.
The limit values of the PWM signal are between
approximately 95%, corresponding to an open air
control valve, and 5%, corresponding to a closed air
control valve. When the air control valve closes, it
interrupts the air supply to the wastegate actuator
and at the same time relieves air pressure from the
wastegate by allowing it to vent to atmosphere. The
wastegate actuator then closes, resulting in increased
charge air pressure.
Figure 10
Air control valve
1.
To high-pressure turbocharger wastegate actuator
2.
Turbocharger 1 Turbine Output Pressure (TC1TOP)
input to sensor
3.
Compressed regulated air supply from chassis air
tank
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

20
1 ENGINE SYSTEMS
Exhaust Gas Recirculation (EGR) System
Figure 11
EGR system
1.
EGR valve assembly
5.
EGR cooler assembly
8.
EGRV coolant supply tube
2.
EGR coolant tube assembly
6.
EGRV coolant return tube
assembly
3.
EGR crossover tube assembly
assembly
4.
EGR coolant tube assembly
7.
EGR cooler supply tube
EGR System Overview
Control Module
(ECM) to control the EGR valve
assembly.
The EGR system reduces Nitrogen Oxides (NOX)
engine emissions by introducing cooled exhaust gas
The EGR system consists of an EGR valve, EGR
into the mixing duct. NOX forms during a reaction
cooler assembly and an O2S
. The EGR valve
between nitrogen and oxygen at high temperatures
assembly is mounted on the rear of the EGR cooler
during combustion. An Oxygen Sensor (O2S) located
assembly.
in the turbo exhaust duct, monitors the oxygen content
The EGR cooler assembly is located on the right side
in the exhaust gas and provides input to the Engine
of the valve cover above the exhaust manifold.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
21
EGR Flow
aftertreatment fuel injector. The O2S has a heater
element that heats the sensor to its normal operating
Exhaust gas from the exhaust manifold flows through
temperature of 780°C (1,436°F). During initial engine
the EGR cooler supply tube to the EGR valve
warm-up, the O2S heater element is activated only
assembly. When the EGR is activated, the EGR
after the engine coolant reaches 40°C (104°F) and
valve assembly opens and allows exhaust gas to
the exhaust gas temperature exceeds 100°C (212°F)
enter the EGR cooler assembly for cooling. Cooled
for more than 30 seconds.
exhaust gas flows from the EGR cooler assembly into
the mixing duct where it is mixed with filtered intake
EGR Open Loop System
air.
During the engine warm-up period and before the
EGR Control
Oxygen Sensor (O2S) reaches its normal operating
temperature, the EGR system operates in open
The ECM monitors signals from the Intake Manifold
loop. In open loop, the EGR system is controlled
Temperature
(IMT) sensor and Engine Coolant
by the ECM based on the charge air temperature,
Temperature
(ECT) sensor to control the EGR
engine coolant temperature, engine speed, and load
system. The EGR is switched off
(EGR valve
conditions. The EGR actuator provides feedback to
assembly closed) if any of the following conditions
the ECM on current valve position through the EGRP
are present:
sensor.
•
Charge air temperature is low
EGR Closed Loop System
•
Intake manifold temperature is low
After the Oxygen Sensor (O2S) reaches its operating
•
Engine coolant temperature is low
temperature, the EGR system switches to closed
•
During engine brake operation
loop operation. In closed loop, the EGR system is
controlled by the ECM based on the O2S readings.
•
When Cold Ambient Protection (CAP) mode is
active
The Oxygen Sensor
(O2S) is installed in the
turbocharger exhaust duct, in front of the
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

22
1 ENGINE SYSTEMS
Aftertreatment (AFT) System
Figure 12
AFT system overview
The Aftertreatment (AFT) System, part of the larger
The sensors measure O2, temperature and pressure
exhaust system, processes engine exhaust to meet
at the center of the exhaust flow.
emissions requirements. The AFT system traps
particulate matter (soot) and prevents it from leaving
Down Stream Injection (DSI)
the tailpipe.
The aftertreatment system injects fuel through the
The AFT system performs the following functions:
fuel doser into the exhaust gas to increase the
temperature necessary for DPF regeneration. The
•
Monitors exhaust gases and controls engine
fuel doser is located in the turbo exhaust duct, directly
operating parameters for emission processing
after the low-pressure turbocharger, on the engine.
and failure recognition
Control of the down stream injection is done by the
•
Cancels regeneration in the event of catalyst or
Engine Control Module (ECM). The ECM receives
sensor failure
data from the aftertreatment sensors directly and
determines when regeneration is required.
•
Monitors the level of soot accumulation in the
Diesel Particulate Filter (DPF) and adapts engine
Pre-Diesel Oxidation Catalyst (PDOC)
operating characteristics to compensate for
increased back pressure
The PDOC is located on the engine after the DSI.
•
Controls engine operating parameters to make
The PDOC does the following:
regeneration automatic
•
Aids in creating an exothermic reaction to improve
•
Maintains vehicle and engine performance during
exhaust emissions
regeneration
•
Allows for more efficient operation of the
aftertreatment system
Sensors
Sensors output an electronic signal based on oxygen
Diesel Oxidation Catalyst (DOC)
(O2), temperature and pressure. The signals are used
The DOC is located in the vehicle exhaust system.
by the control system to regulate the aftertreatment
function.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
23
The DOC does the following:
•
Allows for oxidation
(regeneration) of stored
particulates once back pressure increases to a
•
Oxidizes hydrocarbons and carbon monoxide
predetermined level
(CO) in exhaust stream
•
Stores noncombustible ash
•
Provides heat for exhaust system warm-up
•
Aids in system temperature management for the
AFT Conditions and Responses
DPF
The operator is alerted audibly or with instrument
panel indicators of system status. Automatic or
Diesel Particulate Filter (DPF)
manual regeneration is required when levels of soot
The DPF is located in the vehicle exhaust system.
exceed acceptable limits. For additional information
see the applicable Vehicle Operator Manual and the
The DPF does the following:
vehicle visor placard.
•
Captures and temporarily stores carbon-based
particulates in a filter
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

24
1 ENGINE SYSTEMS
Aftertreatment Fuel Injection Components
Figure 13
Aftertreatment fuel injection components
1.
Fuel doser
4.
Doser fuel from valve tube
6.
Doser fuel to injector tube
2.
Coolant supply port
assembly
assembly
3.
Coolant return port
5.
Feed Injector unit tube assembly
7.
Down Stream Injection (DSI)
assembly
The down stream injection system includes the
•
Fuel lines
following:
The Engine Control Module (ECM) is mounted on the
•
Engine Control Module (ECM)
left side of the engine. The Down Stream Injection
(DSI) assembly is installed on the left rear of the
•
Fuel doser
engine below the cylinder head.
•
Down Stream Injection (DSI) assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
25
When the ECM signals the AFTFSV to open, fuel
pressure increases in the upstream cavity of the
DSI assembly housing. The upstream AFTFIS
immediately signals the ECM that pressure is
increased by available fuel. The ECM then signals
the AFTFD valve to open, allowing a specific amount
of fuel to be pumped through the three fuel tubes to
the fuel doser.
Fuel is injected into the exhaust stream from the fuel
doser which increases the temperature inside the
Diesel Particulate Filter (DPF) in order to convert soot
to ash more efficiently.
The fuel doser is cooled with engine coolant.
Figure 14
Down Stream Injection (DSI) assembly
1.
AFT fuel inlet sensor (AFTFIS) (press and temp)
2.
AFT fuel doser (AFTFD) (valve)
3.
AFT fuel pressure 2 (AFTFP2)
4.
AFT fuel shut-off valve (AFTFSV)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

26
1 ENGINE SYSTEMS
Fuel Management System
Figure 15
Fuel supply system flow
The MaxxForce® 15 engine is equipped with a
Fuel is drawn from the tank and through the frame
high-pressure common rail injection system. The
mounted fuel filter/water separator by a low-pressure
common rail fuel injection system provides fuel under
fuel pump mounted on the engine. Fuel flows from
constant high-pressure to the fuel injectors for optimal
the low-pressure fuel pump through an engine
fuel atomization in the combustion chamber.
mounted fuel filter before being supplied to a
high-pressure pump.
The high-pressure pump
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
27
supplies high-pressure fuel to a pressure pipe rail,
Chassis Mounted Components
which feeds the injectors through individual tubes.
Unused fuel from injectors is returned to the tank
through a passage around the quill tubes in the
cylinder head. The low-pressure fuel pump and
high-pressure pump are assembled as one gear
driven unit on the engine.
The fuel system is controlled by the ECM, various
sensors, and the Fuel Pressure Control Valve (FPCV)
located in the high-pressure pump.
In addition to providing high-pressure fuel to the
injectors, the fuel system also provides low-pressure
filtered fuel to the aftertreatment and cold start assist
systems.
DSI and Fuel Doser
In the aftertreatment system, filtered fuel from the
fuel filter at supply pressure is delivered to the DSI
assembly. The DSI assembly supplies precise
amounts of fuel to the fuel doser.
Cold Start System
During cold weather, fuel is delivered to the Cold
Start Fuel Igniter (CSFI) through the Cold Start Fuel
Solenoid (CSFS). The CSFI then heats the intake air
by injecting and igniting small quantities of fuel into
the mixing duct.
Fuel Filter and Housing
Figure
16
Racor® fuel filter assembly
An orifice and an additional regulator located within
the fuel filter housing work together to reduce fuel
1.
Fuel outlet
pressure to 10 psi for the cold start system solenoid.
2.
Fuel primer pump assembly
Supply system pressure is regulated by a pressure
3.
Fuel inlet from tank
regulator valve located in the supply pump. Excess
4.
Fuel filter water separator assembly
fuel relieved to achieve the pressure reduction is
5.
Water In Fuel (WIF) sensor
returned back to the fuel pump. The maximum
6.
Drain valve
system pressure is regulated to 1 300 kPa (189 psi).
Fuel Filter and Water Separator Assembly
The Racor® fuel filter/water separator
assembly
is standard equipment. There is also an optional
Davco®fuel filter water separator available depending
on customer needs.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

28
1 ENGINE SYSTEMS
Fuel Primer Pump Assembly
the low-pressure fuel pump. The fuel primer pump
assembly is manually operated and is used to prime
The fuel is drawn from the tank through the chassis
the low-pressure fuel system when the system is
fuel filter and water separator assembly, through the
emptied.
chassis mounted fuel primer pump assembly and into
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
29
Engine Mounted Components
Figure 17
Engine mounted fuel system components
1.
Injector (6)
5.
Pressure relief valve
8.
Fuel Pressure Control Valve
2.
Engine Control Module (ECM)
6.
Fuel filter (low pressure)
(FPCV)
3.
Fuel Rail Pressure (FRP) Sensor
7.
Fuel Delivery Pressure (FDP)
9.
Fuel pump (low and
4.
Rail assembly
sensor
high-pressure)
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

30
1 ENGINE SYSTEMS
ECM
Rail Assembly (Fuel Common Rail)
The ECM controls the fuel pressure with a PWM
The fuel common rail is a high-pressure fuel storage
signal to the Fuel Pressure Control Valve (FPCV).
unit. The storage volume of the fuel common rail is
Low pulse width PWM signals equal high-pressure
designed to reduce pressure pulses caused by the
and high pulse width signals equal low pressure. To
high-pressure pump and injectors, and to maintain
protect the system, a PLV (Pressure Limiting Valve)
constant fuel pressure even when large fuel quantities
is installed in the end of the fuel rail. When pressure
are injected into the cylinders. Connection between
exceeds 2,650 +/- 100 bar (38,435 +/-1,450 psi), the
the fuel common rail and injectors are made through
PLV opens and reduces pressure to 1,000-1,200 bar
individual injection lines.
(14,503-17,404 psi) to facilitate limp-home operation.
Fuel Rail Pressure (FRP) Sensor
The fuel system is controlled by the ECM. Various
engine sensors are input into fueling calculations. The
The FRP sensor is a variable resistance sensor that
ECM then controls the FPCV and the injectors for
monitors the fuel pressure in the high-pressure fuel
proper engine operation. The injection timing and
rail.
quantity are calculated in the Engine Control Module
The FRP sensor is mounted in the front of the
(ECM) and implemented by solenoid valve controlled
high-pressure pipe rail on the left side of the engine.
injectors.
Pressure Relief Valve
Fuel Filter
The pressure relief valve maintains fuel pressure in
The fuel filter housing assembly is located on the
the rail assembly below 265 000 kPa (38,500 psi).
left side of the engine and has a disposable spin-on
If the rail assembly pressure exceeds this value, the
type filter element. An Engine Fuel Delivery Pressure
relief valve opens and allows fuel to flow to the return
(FDP) sensor is installed on the front side of the
line, and back to the tank. When the relief valve
fuel filter housing assembly and it measures fuel
opens, the system goes into a limp-home mode and
pressure between the low-pressure fuel pump and
a steady rail pressure of 120 000 kPa (17,400 psi) is
the filter element. An additional function of the fuel
maintained until the engine is switched off. This will
filter housing assembly is fuel system self-deaeration.
reset to normal operation upon the next key-in event.
The air separated from fuel is pushed back into the
fuel tanks through the return line.
Injector
The fuel filter housing assembly is equipped with
The MaxxForce®
15
engine is equipped with
two additional ports to provide filtered fuel to the
electronically controlled solenoid valve injectors.
aftertreatment system and to the cold start assist
During engine operation, injectors are supplied at
system. An orifice regulator is integrated into the
all times with high-pressure fuel, and the injector
fuel filter housing assembly and regulates the fuel
solenoid valves open up to three times per cycle. The
pressure for the cold start assist system to 70 kPa
injectors are positioned vertically in the center of the
(10 psi).
cylinder head and are held in place by injector clamps.
The seal between the injectors and the combustion
Fuel Pump
chamber consists of a copper washer on the tip of
Fuel injection pressure is generated by the
each injector.
high-pressure side of the fuel pump. High-pressure
The use of solenoid valve controlled injectors allows
fuel quantity from the fuel pump is controlled by
three injections per cycle. The first injection is
a FPCV. The fuel pump supplies both low and
used to reduce combustion noise and emissions by
high-pressure fuel from one unit. The fuel pump
introducing a small amount of fuel into the cylinder,
is gear driven and is fuel lubricated. Fuel from the
preventing a rapid rise in cylinder pressure when
low-pressure side is forced through the fuel filter
combustion begins.
This first injection occurs
housing assembly and into the high-pressure side of
only during idling and in partial load mode. The
the fuel pump. The flow of fuel to the suction chamber
second injection is the main injection. This injection
of the high-pressure pump is controlled by the FPCV
allows high temperatures to be maintained during
in order to control the high-pressure fuel output.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
31
combustion, but not long enough to allow generation
of large soot amounts. The third injection is done
during the power stroke to maximize cylinder
temperature and reduce engine soot generation.
Engine Lubrication System
Figure 18
Oil system overview (typical)
Engine oil pressure is generated by an oil pump
The front of the crankcase contains oil passages
located under the oil pan which is driven off the
that supply oil to the gear train and air compressor.
crankshaft gear. The oil cooler and filter housing
These passages ultimately supply oil to the cylinder
are located on the right side of the engine. The oil
head through the front hollow dowel that locates the
pump contains the oil pressure regulator. Oil flows to
cylinder head to the engine block. Oil drains back to
the cylinder head by means of an internal passage.
the crankcase through passages in the cylinder head.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

32
1 ENGINE SYSTEMS
Oil Flow and Components
Figure 20
Oil flow through filter when oil is warm
1.
Main oil gallery
Figure 19
Oil flow through filter when oil is cold
2.
Turbocharger oil supply line
1.
Main oil gallery
3.
Turbocharger oil drain tube
2.
Turbocharger oil supply line
4.
Oil filter element
3.
Turbocharger oil drain tube
5.
Bypass valve (oil filter)
4.
Oil filter element
6.
Oil pan
5.
Bypass valve (oil filter)
7.
Oil pump
6.
Oil pan
8.
Bypass valve (oil cooler)
7.
Oil pump
9.
Oil pick-up tube
8.
Bypass valve (oil cooler)
10. Engine oil cooler
9.
Oil pick-up tube
10. Engine oil cooler
When the oil is warm, unfiltered oil is drawn from the
oil pan through the pick-up tube to the oil pump. The
When the engine oil is cold, oil is drawn from the
oil pump pushes the warm oil through the oil cooler
oil pan through the pick-up tube to the oil pump.
towards the oil filter. The bypass valves will be closed
Due to the high viscosity of the cold oil, both bypass
due to the lower viscosity of the oil and its ability to
valves open. These bypass valves provide immediate
flow through the oil cooler and oil filter. Filtered oil is
lubrication to engine components when cold oil with
directed to the turbocharger oil supply line and main oil
high viscosity may not pass through the oil filter easily.
gallery where it is distributed to engine components.
The bypass valves allow oil to bypass the engine oil
Oil that exits the oil cooler flows through a return
cooler and oil filter.
shutoff valve that prevents the oil from draining back
The bypass valve will also allow oil to bypass the oil
into the oil pan. From the return shutoff valve, oil
filter in case the oil filter becomes restricted. This
enters the oil filter element and flows from the outside
prevents a restricted oil filter from blocking oil flow to
to the inside of the filter element to remove debris.
engine components.
When the filter is restricted, an oil filter bypass valve
opens and allows oil to bypass the filter so engine
lubrication is maintained. If the oil pressure inside
the oil filter element is too high, an oil pressure relief
valve, located at the bottom of the oil filter element
housing, allows excess oil to flow to the oil gallery.
Clean oil enters the crankcase directly from the
oil filter housing to lubricate the crankshaft, air
compressor, intermediate gears, and turbochargers.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
33
The crankshaft has cross-drillings that direct oil to the
housing to the center housing of each turbocharger.
connecting rods.
Oil drains back to the oil pan through the low and
high-pressure turbocharger oil return tubes connected
Piston cooling jets continuously direct cooled oil to the
to the crankcase.
bottom of the piston crowns.
The turbochargers are lubricated with filtered oil from
an external supply tube that connects the oil filter
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

34
1 ENGINE SYSTEMS
Engine Cooling System
Cooling System Components
Figure 21
Cooling system components
1.
EGR coolant tube assembly
4.
EGR coolant tube assembly
8.
Water pump inlet
(primary EGR cooler)
(secondary EGR cooler)
9.
Coolant Control Valve (CCV)
2.
EGR coolant return (secondary
5.
Engine Coolant Temperature 1
assembly
EGR cooler)
(ECT1) sensor (behind ISC)
10. Coolant adapter
3.
EGR coolant return (primary
6.
Thermostat housing cover
11. Engine Coolant Pressure 1
EGR cooler)
7.
Water pump
(ECP1) sensor
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
35
Cooling System Flow
Figure 22
Cooling system flow
The water pump is located on the front cover and
the thermostat can direct into two directions to exit
draws coolant from the radiator through the coolant
the cylinder head.
inlet at the lower right side of the engine. The water
When the thermostat is closed, coolant is directed
pump pushes coolant to the oil cooler through a
through the bypass port, crankcase and front cover,
passage in the front cover.
and into the water pump.
Coolant flows to the crankcase and through the water
When the thermostat is open, the bypass port is
jacket from rear to front. This coolant flows around
blocked, and coolant is directed from the engine into
the cylinder liners to absorb heat from combustion.
the radiator. Coolant passes through the radiator
The coolant may also pass through an optional engine
and is cooled by moving air from the radiator fan.
coolant heater.
The coolant returns to the engine first through the
Coolant flows through the cylinder head water jackets
transmission cooler, then through the engine water
towards the thermostat cavity at the front of the
inlet pipe.
cylinder head. Depending on coolant temperature,
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

36
1 ENGINE SYSTEMS
The air compressor is cooled with engine coolant
The surge tank provides expansion space for coolant
supplied by a hose from the left side of the crankcase.
and deaerated the cooling system. The following four
Coolant passes through the air compressor cylinder
vents provide coolant to the tank:
head and returns through a hose back into the
•
Rear and Front EGR Cooler
crankcase through the engine water inlet pipe.
•
Main radiator vent
The fuel doser is also cooled with engine coolant
supplied by the oil cooler module. Coolant passes
•
Low temperature radiator vent
through the fuel doser and is returned to the engine
The surge tank returns coolant through the surge line,
water inlet pipe.
back to the water pump inlet. Cab heat is provided by
The oil cooler assembly receives coolant from the
the heater core, which receives warmed coolant from
front cover water outlet pipe. Coolant passes between
the coolant supply housing.
the oil cooler plates and returns to the crankcase.
Coolant from the water pump also flows through
Thermostat Operation
an external pipe to the rear EGR cooler and to the
front EGR cooler. Coolant passes between the EGR
The MaxxForce®
15
engine is fitted with two
cooler plates. Rear EGR cooler section coolant
thermostats in a common housing to ensure
travels parallel to the exhaust flow. The front EGR
sufficient coolant flow in all operating conditions.
cooler section coolant flows opposite to the exhaust
The thermostats are located at the front of the engine
flow. The coolant from the rear EGR cooler is then
on the right side of the cylinder head.
returned to the water inlet pipe. The coolant from the
The thermostat housing assembly has two outlets.
front EGR cooler is returned to an external pipe to
One directs coolant to the radiator when the engine is
the back of the oil cooler module. Deaeration ports
at operating temperature. The second outlet directs
are located on the top of both the rear and front EGR
coolant to the water pump until the engine reaches
coolers which directs coolant and trapped air to the
operating temperature. The thermostats begin to
coolant surge tank.
open at 88°C (190°F) and are fully open at 103°C
Coolant from the water pump also flows through
(217°F).
the Interstage cooler to regulate the charge air
When engine coolant is below 88°C (190°F), the
temperature. Flow through the Interstage cooler is
thermostats are closed and block coolant flow to the
controlled by the Coolant Controlled Valve (CCV).
radiator. Coolant is forced to flow through a bypass
Depending on the coolant flow, CCV sends coolant
port back to the water pump.
through the Low Temperature Radiator
(LTR) or
bypass directly to the Interstage Cooler (ISC). When
When coolant temperature reaches the opening
the charge air temperature is too low, CCV bypasses
temperature of 88°C (190°F), the thermostats open
the LTR and directs all the coolant through the ISC.
and allow some coolant to flow to the radiator. When
When the charge air temperature increases, CCV
coolant temperature exceeds
103°C (217°F), the
directs a percentage of coolant to the LTR before it
lower seat blocks the bypass port and directs full
enters the ISC to cool the charge air. If the engine
coolant flow to the radiator.
coolant temperature is too high, CCV sends all of the
coolant flow through the LTR and through the ISC to
help cool the engine faster.
Coolant Control Valve (CCV) Assembly Operation
Coolant from the CCV also flows to the EGR valve.
The CCV assembly is installed on the lower right side
Flow through the EGR valve is supplied by an external
of the engine and controls coolant flow to the ISC,
pipe that also supplies to the Interstage cooler. The
EGR valve, and LTR.
EGR valve coolant flow is then returned to the top port
The CCV assembly has two separate solenoid
of the surge tank.
actuated valves: Coolant Mixer Valve (CMV) and
Coolant Flow Valve
(CFV). The CMV and the
CFV are part of the CCV assembly and cannot
be serviced separately. The CMV and CFV solenoids
are controlled by two separate Pulse Width Modulated
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
37
(PWM) signals from the ECM. The PWM signal duty
CMV
cycles vary between 0% and 100% depending on the
The mixing valve varies the amount of coolant that
coolant and charge air temperature.
passes through the low temperature radiator, or LTR.
With a 0% signal to the mixing valve, all coolant flows
CFV
to the LTR before entering the ISC and the EGR valve.
The flow valve varies the rate of coolant flow to the
When 100% duty cycle is applied to the mixing valve,
mixing valve. At 0% duty cycle the flow valve is fully
full coolant flow bypasses the LTR and is directed to
open and coolant to the mixing valve is not restricted.
the ISC and EGR valve.
When the flow valve receives 100% duty cycle, it
partially closes restricting coolant to the mixing valve.
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

38
1 ENGINE SYSTEMS
MaxxForce®Engine Brake System
brake housing assemblies. This provides progressive
braking capabilities with the retarding effect of two
The MaxxForce®engine brake is standard equipment
cylinders, four cylinders, or all six cylinders.
on the MaxxForce® 15L engine. The engine brake
uses engine oil pressure to improve the engine
braking power by holding the exhaust valves slightly
open during the cylinder compression and power
strokes.
During engine brake operation, both the compression
and expansion strokes of the power cylinders are used
to absorb road speed energy through the powertrain.
The operator can enable or disable the engine brake
by pressing a dash mounted ON/OFF switch.
Engine Brake System Components
Figure 23
Engine brake housing
1.
Slave piston
2.
Master piston
3.
Slave piston adjustment screw
4.
Engine brake solenoid and spool valve
The engine brake consists of three identical housing
assemblies; each housing is positioned over two
cylinders. The housing assembly is mounted to the
supports for the rocker shaft assembly with studs and
nuts. The rocker arm and exhaust bridge assembly
is used to transfer force from the slave piston to the
exhaust valves.
The engine brake is controlled by the ECM. The
control circuit for the engine brake permits the
operation of either one, two, or all three engine
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
39
Figure 24
Engine brake system
1.
Check valve
7.
Slave piston
13. Rocker arm shaft oil passage
2.
High-pressure oil passage
8.
Master piston spring
14. Engine oil pump
3.
Slave piston adjustment screw
9.
Slave piston spring
15. Engine oil pan
4.
Master piston
10. Exhaust rocker arm
16. Exhaust valve
5.
Spool valve
11. Exhaust bridge
17. Lost motion assembly
6.
Oil drain passage
12. Lost motion rocker arm
Engine Brake Operation
arm. Oil fills the master cylinder and high-pressure
oil passage between the master cylinder and slave
The engine brake is operated by pressurized engine
cylinder. The master piston will follow the movement
oil. Engine oil is supplied to the engine brake through
of the lost motion rocker arm. The check valve will
a passage in the rocker shaft assembly. The spool
close when the master piston moves upward causing
valve controls the flow of oil to the engine brake
the pressure in the high-pressure oil passage to rise.
components.
This increase in pressure causes the slave cylinder to
When the spool valve is moved by the engine brake
move downward contacting the exhaust valve bridge
solenoid, low pressure oil passes through the spool
and open the exhaust valves.
valve. The oil flow opens a check valve and flows
The ECM will disable the fuel injectors during engine
into the high-pressure oil passage to supply oil to
brake operation. Without fuel injection or combustion,
the master and slave cylinders. The oil pressure
the power stroke is transformed into an energy
overcomes the spring in the master cylinder and
absorption stroke. This will create an engine braking
forces the master piston toward the lost motion rocker
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

40
1 ENGINE SYSTEMS
force at the flywheel. As the lost motion rocker arm
moves down, the master piston will also move down
and reduce the oil pressure on the slave piston. As a
result, the slave piston will move upward and return
exhaust valve operation to the engine valve train.
De-energizing the solenoid allows oil to drain back into
the engine oil pan through the drain passages in the
spool valve.
Open Crankcase Breather System
Open Crankcase Breather System Components
Figure 25
Open crankcase breather system
1.
Breather inlet tube
3.
Breather outlet tube
2.
Breather filter assembly
4.
Breather drain tube
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
41
Open Crankcase Breather System Operation
breather inlet tube. From the breather inlet tube,
blow-by gases enter the breather filter assembly
The open crankcase breather system uses an engine
where heavy oil particles are separated and drain into
mounted oil separator to return oil to the crankcase
the oil pan through check valves in oil drain tube.
and vent blow-by gases to the atmosphere. The
primary component of the system is the breather filter
The cleaned blow-by gases exit to the atmosphere
in the breather filter assembly. The breather filter
through the breather outlet tube.
separates oil mist from blow-by gases.
The blow-by gases exit the crankcase from the valve
cover and enter the breather system through the
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

42
1 ENGINE SYSTEMS
Cold Start Assist System
Figure 26
Cold start assist system components
1.
Cold Start Fuel Igniter (CSFI)
3.
Cold Star Fuel Solenoid (CSFS)
6.
Cold Start Relay (CSR)
2.
Solenoid to injector tube
4.
Filter to solenoid tube assembly
assembly
5.
Relay support assembly
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

1 ENGINE SYSTEMS
43
Cold Start Fuel Igniter (CSFI)
Cold Start Fuel Solenoid (CSFS)
The CSFS valve is located on the left side of the
engine and is controlled by the ECM. The CSFS valve
is supplied regulated low pressure fuel from the fuel
filter housing assembly through the solenoid to injector
tube.
When the ECM provides 12 volts to the solenoid valve,
the CSFS valve opens and allows fuel to flow to the
CSFI through the solenoid to injector tube. Ground
control is provided by the ECM.
Cold Start Assist System Operation
The cold start assist system operates only in
temperatures lower than 11°C (52°F).
When the vehicle operator turns the ignition switch
Figure 27
Cold Start Fuel Igniter (CSFI)
to ON, the wait-to-start lamp in the instrument cluster
1.
Electrical connection
illuminates. The ECM activates the Cold Start Relay
2.
Insulation
(CSR) based on the temperature readings from
3.
Fuel line connection
the Engine Coolant Temperature (ECT), Engine Oil
4.
Metering device
Temperature (EOT), and the Intake Air Temperature
5.
Vaporizer filter
(IAT) sensors. The CSR then energizes the CSFI for
6.
Vaporizer tube
approximately 45 seconds.
7.
Heater element
Once the CSFI is heated to approximately 1 000°C
8.
Protective sleeve
(1,832°F), the wait-to-start lamp starts to flash and
the operator needs to crank the engine. When the
engine starts rotating, the solenoid valve opens and
The function of the CSFI is to spray ignited fuel into the
allows fuel to enter the CSFI through the solenoid to
mixing duct. The ignited fuel warms incoming air to
injector tube. The fuel passes through the vaporizer
assist starting a cold engine. The CSFI is essentially
tube inside the CSFI. The vaporized fuel then mixes
a fuel injector and glow plug in one unit.
with the intake air and ignites in contact with the heater
The CSFI has an internal fuel metering device, a
element.
vaporizer filter, a vaporizer tube, a heater element,
Once the engine starts, the CSFI remains energized
and a protective sleeve. The protective sleeve has
and fuel continues to be injected to the CSFI, and the
holes that allow enough air to pass through the CSFI
wait-to-start lamp continues to flash for a maximum of
to enable the fuel vaporization and combustion.
4 minutes. When the wait-to-start lamp stops flashing,
The CSFI is installed on the left front side of the engine
the CSFI and the solenoid valve are deactivated. If
in the mixing duct.
the operator accelerates while the wait-to-start lamp
flashes, the cold start assist system will shut down.
Cold Start Relay (CSR)
The CSR is located on the rear left side of the
engine. The CSR provides voltage to the CSFI and is
controlled by the Engine Control Module (ECM).
EGES-515-1
Read all safety instructions in the “Safety Information” section of this Manual before doing any procedures.
Follow all warnings, cautions, and notes.
©2012 Navistar, Inc. All rights reserved.

44
1 ENGINE SYSTEMS
Electronic Control System
Continuous calculations in the ECM occur in the
foreground and background.
Electronic Control System Components
•
Foreground calculations are faster than
The MaxxForce® 15 engine is equipped with an
background calculations and are normally more
Engine Control Module
(ECM) that monitors and
critical for engine operation. Engine speed control
controls all functions of the engine and aftertreatment
is an example.
system.
•
Background calculations are normally variables
that change at slower rates. Engine temperature
Operation and Function
is an example.
The Engine Control Module (ECM) monitors and
Diagnostic Trouble Codes (DTCs) are set by the
controls engine performance to ensure maximum
microprocessor if inputs or conditions do not comply
performance and adherence to emissions standards.
with expected values.
The ECM performs the following functions:
Diagnostic strategies are also programmed into the
•
Provide reference voltage (VREF)
ECM. Some strategies monitor inputs continuously
and command the necessary outputs for correct
•
Condition input signals
performance of the engine.
•
Process and store control strategies
•
Control actuators
Diagnostic Trouble Codes
Diagnostic Trouble Codes
(DTCs) are stored by
the ECM if inputs or conditions do not comply with
Reference Voltage (VREF)
expected values. Diagnostic codes for the 2010
The ECM supplies 5 volt VREF signals to input
MY are communicated using the Suspect Parameter
sensors in the electronic control system.
By
Number (SPN) and Failure Mode Indicator (FMI)
comparing the 5 volt VREF signal sent to the sensors
identifiers, and are accessed using an electronic
with their respective returned signals, the ECM
service tool with ServiceMaxx™ diagnostic software
determines pressures, positions, and other variables
or a generic scan tool as well.
important to engine and vehicle functions.
Microprocessor Memory
Signal Conditioner
The ECM microprocessor includes Read Only
Memory (ROM) and Random Access Memory (RAM).
The signal conditioner in the internal microprocessor
converts analog signals to digital signals, squares up
ROM
sine wave signals, or amplifies low intensity signals to
a level that the control module’s microprocessors can
ROM stores permanent information for calibration
process.
tables an