TABLE OF CONTENTS - Continued
TC-86AREPAIRING - TIMING GOVERNING POSITIVE GOVERNOR
DEVIATION.............................................266
TC-91AREPAIRING - VEHICLE SPEED SENSOR TROUBLE CODES. . . .270
TC-94AREPAIRING - VEHICLE THEFT ALARM TROUBLE CODES......280
SENTRY KEY IMMOBILIZER SYSTEM
SK-1AIDENTIFYING SENTRY KEY IMMOBILIZER PROBLEMS........286
SK-2AREPAIRING - PCM STATUS FAILURE.......................290
SK-3AREPAIRING - ROLLING CODE FAILURE.....................294
SK-4AREPAIRING - SERIAL LINK EXTERNAL FAILURE..............298
SK-5AREPAIRING - TRANSPONDER COMMUNICATION FAILURE.....302
SK-6ATRANSPONDER CRC (CYCLIC REDUNDANCY CHECK)
FAILURE...............................................306
SK-7AREPAIRING - TRANSPONDER ID MISMATCH................310
SK-8AREPAIRING - TRANSPONDER RESPONSE MISMATCH........314
SK-9AREPAIRING - VIN MISMATCH..............................318
NO TROUBLE CODE TESTS
NTC-1ANO TROUBLE CODE TEST MENU..........................322
NTC-2ACHECKING GLOW PLUG OPERATION......................324
NTC-3ACHECKING FUEL INJECTION PUMP CIRCUITS...............328
NTC-4ACHECKING THE PCM POWER AND GROUNDS..............330
NTC-5ACHECKING ENGINE COOLANT SENSOR CALIBRATION AND
RADIATOR FAN OPERATION..............................332
NTC-6ACHECKING ACCELERATOR PEDAL POSITION SENSOR
CALIBRATION...........................................334
NTC-7ACHECKING BOOST PRESSURE SENSOR CALIBRATION.......336
NTC-8ACHECKING FUEL TEMPERATURE SENSOR CALIBRATION.....338
NTC-9ACHECKING EGR SYSTEM.................................340
NTC-10ACHECKING THE FUEL HEATER AND THE CRANKCASE VENT
HEATER................................................342
NTC-11ACHECKING RADIATOR FAN OPERATION....................352
NTC-12ACHECKING THE ENGINE MECHANICAL SYSTEMS...........366
NTC-13ACHECKING THE TURBOCHARGER OPERATION..............368
SPEED CONTROL TESTS
SC-1ACHECKING SPEED CONTROL OPERATION..................372
SC-2ACHECKING SPEED CONTROL OPERATION..................376
SC-3ACHECKING SPEED CONTROL OPERATION..................378
SC-4ACHECKING SPEED CONTROL OPERATION..................386
SC-5ACHECKING SPEED CONTROL OPERATION..................388
SC-6ACHECKING CRUISE INDICATOR OPERATION................390
NO START TESTS
NS-SELNO START SELECTION MENU.............................392
NS-1AREPAIRING A NO CRANK CONDITION......................394
NS-2AREPAIRING A NO RESPONSE CONDITION..................400
NS-3AREPAIRING - NO START..................................410
NS-4AREPAIRING A START AND STALL CONDITION................418
NS-5ACHECKING THE ENGINE MECHANICAL SYSTEMS...........420
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3.2 Functional Operation
3.2.1 ECM On-Board Diagnostics
The ECM has been programmed to monitor many different circuits of the diesel fuel injection
system. This monitoring is called ``on-board diagnosis''.
Certain criteria must be met for a diagnostic trouble code to be entered into the ECM memory. The
criteria may be a range of: engine rpm, engine temperature, and/or input voltage to the ECM. If
all of the criteria for monitoring a system or circuit are met and a problem is sensed, then a trouble
code will be stored in the ECM.
It is possible that a trouble code for a monitored circuit may not be entered into the ECM memory
even though a malfunction has occurred. This may happen when the monitoring criteria have not
been met.
The ECM compares input signal voltages from each input device with specifications (the
established high and low limits of the range) that are programmed into it for that device. If the input
voltage is not within specifications and other trouble code criteria are met, a trouble code will be
stored in the ECM memory.
3.2.2 ECM Operating Modes
As input signals to the engine control module (ECM) change, the ECM adjusts its response to
output devices. For example, the ECM must calculate a different fuel quantity and fuel timing for
idle than it does for wide open throttle. There are several different modes of operation that
determine how the ECM responds to the various input signals.
Ignition Switch On (Engine Off Mode)
When the ignition switch activates the fuel injection system, the following actions occur:
1. The ECM determines atmospheric air pressure from the atmospheric pressure sensor
located in the ECM.
2. The ECM energizes the fuel quantity actuator and the fuel shudown solenoid if no faults
are present.
If the engine is not started within 5 seconds of ignition on, the ECM deactivates the fuel quantity
actuator and the fuel shutdown solenoid to prevent overheating.
Engine Start-Up Mode-The ECM uses the engine temperature sensor, fuel temperature sensor,
atmospheric pressure sensor, boost pressure sensor and the engine speed sensor to determine
fuel delivery during this mode.
Normal Driving Modes- Engine idle, warm-up, acceleration, deceleration and wide open throttle
modes are all controlled based on the sensor inputs to the ECM and are modified based on
engine temperature, boost pressure and engine speed.
Overheat Protection Mode- If engine temperature becomes too hot, the ECM activates high
speed radiator fan operation and limits fuel quantity for engine protection.
Limp-In Modes- The ECM operates in limp-in mode when certain system faults are detected.
The ECM operates in one of the following modes based on the severity of the fault:
1. 10% torque reduction.
2. 50% torque reduction.
3. Engine speed limited to 1100 rpm.
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4.0 SYSTEM COMPONENT LOCATIONS
4.1 Engine Control Module
2.5L
CAV CKT/COLOR FUNCTION
1 Z12 BK/TN Ground
2 A142 DG/OR Diesel Power Relay Output
3 K90 TN Starter Relay Control
5 C13 DB/OR A/C Compressor Clutch Control
6 K159 VT/RD Engine Speed Sensor Signal
Output
8 C103 DG/LB A/C Switch Signal
9 K29 WT/PK Secondary Brake Switch Signal
11 K6 VT/WT 5-Volt Supply
12 K151 WT Low Idle Position Switch Sense
13 K21 BK/RD Intake Air Temperature Sensor
Signal
17 C24 DB/PK Low Speed Fan Control
20 L50 WT/TN Primary Brake Switch Signal
23 K167 BR/YL Accelerator Pedal Position
Sensor Ground
24 K22 OR/DB Accelerator Pedal Position
Sensor Signal
27 Z12 BK/TN Ground
28 A142 DG/OR Diesel Power Relay Output
29 K35 GY/YL EGR Solenoid Control
30 V38 LB/RD Speed Control Lamp Control
33 K51 DB/YL Diesel Power Relay Control
34 G85 OR/BK Diagnostic/Glow Plug Lamp
Control
38 G56 OR/BK Immobilizer Signal
39 K9 LB 5-Volt Supply
40 K1 DG/RD Boost Pressure Sensor Signal
41 C137 YL High Speed Fan ControlCAV CKT/COLOR FUNCTION
42 K152 WT/DG Glow Plug Relay #1 Control
43 K252 LG/OR Glow Plug Relay #2 Control
45 D21 PK ISO K-line
46 K119 LG/BK Clutch Pedal Switch Signal
47 F87 WT/BK Ignition Switch Supply
50 K7 OR 5-Volt Supply
51 G7 WT/OR Vehicle Speed Sensor Signal
52 C18 DB A/C Pressure Sensor Signal
53 K156 GY Fuel Temperature Sensor Signal
54 K2 TN/BK Engine Coolant Temperature
Sensor Signal
55 K68 LG/YL Needle Movement Sensor
Ground
56 K134 LB/BK Control Sleeve Position Sensor
Signal
57 K57 LG/OR Middle Tap
58 K135 WT/BK Measure Coil
59 K140 TN/WT Fuel Quantity Actuator Control
60 V37 RD/LG Speed Control Switch Signal
61 K4 BK/LB Sensor Ground
62 K67 BR/BL Needle Movement Sensor
Signal
66 K140 TN/WT Fuel Quantity Actuator Control
67 K24 GY/BK Engine Speed Sensor Signal
69 K3 BK/VT Engine Speed Sensor Ground
77 K153 OR/DG Fuel Shutdown Solenoid Control
79 K126 LG Fuel Timing Solenoid Control
80 K140 TN/WT Fuel Quantity Actuator Control
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TEST NTC-1ANO TROUBLE CODE TEST MENU
First, check all Technical Service Bulletins that relate to this driveability problem. Perform corrective
actions if indicated; otherwise continue.
1.NO TROUBLE CODE COMPLETE TEST(non-monitored and monitored circuits)
PerformNTC-2AthroughNTC-13Ain sequence until the driveability problem is found.
NO TROUBLE CODE MENU
CHECKING GLOW PLUG OPERATION.........................................NTC-2A
CHECKING FUEL INJECTION PUMP CIRCUITS.................................NTC-3A
CHECKING THE PCM POWER AND GROUND CIRCUITS.........................NTC-4A
CHECKING ENGINE COOLANT SENSOR CALIBRATION..........................NTC-5A
CHECKING ACCELERATOR PEDAL SENSOR CALIBRATION......................NTC-6A
CHECKING BOOST PRESSURE SENSOR CALIBRATION.........................NTC-7A
CHECKING FUEL TEMPERATURE SENSOR CALIBRATION.......................NTC-8A
CHECKING EGR SYSTEM...................................................NTC-9A
CHECKING THE FUEL HEATER.............................................NTC-10A
CHECKING RADIATOR FAN OPERATION.....................................NTC-11A
CHECKING THE ENGINE MECHANICAL SYSTEMS.............................NTC-12A
CHECKING THE TURBOCHARGER..........................................NTC-13A
2.NO TROUBLE CODE QUICK INDIVIDUAL TEST(individual test only)
If you suspect any of the above items to be the cause of the vehicle's driveability problem, perform
the associated test(s) individually.Return to No Trouble Code Menu if driveability problem still
exists, or perform No Trouble Code Complete Test.
3.NO TROUBLE CODE QUICK SYMPTOM TEST(symptom test only)
Symptom checks cannot be used properly unless the driveability problem characteristic actually
happens while the vehicle is being tested. To reduce diagnostic time, ensure that DTC TEST and
appropriate GENERAL INFORMATION sections have been reviewed before attempting to diagnose
a symptom.
Select the symptom that most accurately describes the vehicle's driveability problem and then
perform the test routine that pertains to this symptom. Perform each routine test in sequence until
the problem is found. For definitions, see Section 12.0 in the GENERAL INFORMATION section in
this manual.
NOTE:For all component locations seeGeneral Information Section 4.0in this manual.
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TEST NS-3ACONTINUED - REPAIRING - NO START
*Perform Verification TEST VER-1A. **Check connectors - Clean / repair as necessary.
TEST NS-3A INSPECT ALL FUEL
CONTINUED FROM LINES FOR ARE ANY PROBLEMS YES REPAIR AS
THE PREVIOUS RESTRICTIONS LEAKS EVIDENT? NECESSARY.*
PAGE. OR OTHER PROBLEMS.
NO
REFER TO THE CHECK FUEL INJECTION
SERVICE MANUAL AND IS THE FUEL YES PUMP TIMING. CHECK
PERFORM THE FUEL PRESSURE OK? FUEL SUPPLY FOR
SYSTEM PRESSURE CONTAMINATION SUCH
TEST. AS WATER.*
NO
CHECK THE FUEL
PUMP DRIVE. IF OK,
REPLACE THE FUEL
INJECTION PUMP
ASSEMBLY.*
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