TEST ACTION APPLICABILITY
8 Turn the ignition off.
Remove and inspect Fuse #16 from Fuse Block No.1
Is the fuse open?All
Ye s!Go To 9
No!Go To 11
9 Turn the ignition off.
Disconnect the ECM harness connectors.
Install a good fuse in place of Fuse #16 in Fuse Block No.1
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Remove and inspect Fuse #16 from Fuse Block No.1.
Is the fuse open?All
Ye s!Repair the Engine Control Relay Output circuit for a short to
ground.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 10
10 The Fuel Injectors, Crankcase Heater, Water In Fuel Sensor and related circuits can
cause Fuse #16 in Fuse Block No.1 to open. Use the Service Information Wiring
Diagrams and check these circuits/components for shorted circuits.
Were any problems found.All
Ye s!Repair or replace shorted circuit/component as necessary.
Perform ROAD TEST VERIFICATION - VER-2.
No!Replace and program the ECM in accordance with the Service
Information.
Perform ROAD TEST VERIFICATION - VER-2.
11 Turn the ignition off.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Control circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Choose the appropriate result.All
Test light is on for all circuits.
Test Complete.
Test light is on for 1 or 2 circuits
Repair the Engine Control Relay Output circuit(s) for an open.
Perform ROAD TEST VERIFICATION - VER-2.
Light off for all circuits.
Go To 12
237
DRIVEABILITY - DIESEL
*CHECKING THE POWER AND GROUNDS ÐContinued
TEST ACTION APPLICABILITY
12 Turn the ignition off.
Substitute the Engine Control Relay with a known good relay.
Disconnect the ECM harness connectors.
Connect a jumper wire between ground and the Engine Control Relay Signal circuit
in ECM C2 harness connector cavity 44.
Turn the ignition on.
Using a 12-volt test light connected to ground, check the Fused Engine Control Relay
Output circuits at the ECM C2 harness connector cavities 1, 3 and 5.
Does the test light illuminate brightly?All
Ye s!Replace the initial Engine Control Relay.
Perform ROAD TEST VERIFICATION - VER-2.
No!Go To 13
13 Turn the ignition off.
Remove the Engine Control Relay from Fuse Block No.1
Using a 12-volt test light connected to ground, check both Battery (+) circuits at the
Engine Control Relay connector in Fuse Block No.1
Does the test light illuminate brightly for each circuit?All
Ye s!Repair the Engine Control Relay Output circuit for an open
between the Engine Control Relay connector in Fuse Block No. 1
and ECM C2 harness connector cavities 1, 3 and 5. It may be
necessary to replace the Fuse Block No. 1 to repair this circuit.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Battery (+) Supply circuits to the Engine Control
Relay.
Perform ROAD TEST VERIFICATION - VER-2.
14 Turn the ignition off.
Remove the Engine Control Relay from Fuse Block No. 1.
Disconnect the ECM harness connectors.
Measure the resistance of the Engine Control Relay Control circuit.
Is the resistance below 10.0 ohms?All
Ye s!Go To 15
No!Repair the Engine Control Relay Control circuit for an open.
Perform ROAD TEST VERIFICATION - VER-2.
15 Turn the ignition off.
Remove the Engine Control Relay from Fuse Block No. 1.
Disconnect the ECM harness connectors.
Measure the voltage of the Engine Control Relay Control circuit.
Is the voltage below 1.0 volts?All
Ye s!Replace and program the ECM in accordance with the Service
Information.
Perform ROAD TEST VERIFICATION - VER-2.
No!Repair the Engine Control Relay Control circuit for a short to
voltage.
Perform ROAD TEST VERIFICATION - VER-2.
238
DRIVEABILITY - DIESEL
*CHECKING THE POWER AND GROUNDS ÐContinued
Symptom:
*ENGINE WILL NOT CRANK
POSSIBLE CAUSES
BATTERY CABLE HIGH RESISTANCE
BATTERY CABLES
CHECKING ECM POWER AND GROUNDS
CHECKING FOR TCM CODES
ECM
ECM CODES PRESENT
IGNITION SWITCH OUTPUT (START) CIRCUIT OPEN
MECHANICAL PROBLEM
SKREEM CODES PRESENT
STARTER MOTOR
STARTER MOTOR RELAY
STARTER MOTOR RELAY CIRCUIT(S) OPEN
STARTER MOTOR RELAY CIRCUIT(S) SHORTED TO GROUND
STARTER RELAY CONTROL CIRCUIT SHORTED TO VOLTAGE
STARTER RELAY OUTPUT CIRCUIT OPEN
TEST ACTION APPLICABILITY
1 Turn the ignition off.
NOTE: The battery must be fully charged before diagnosing a no crank
condition.
Inspect the battery cables for corrosion, looseness or other problems.
Is there evidence of problems?All
Ye s!Repair as necessary.
Perform NO START VERIFICATION - VER-1.
No!Go To 2
2 Turn the ignition off.
Remove the Starter Motor Relay from the Fuse/Relay Block.
Connect a test light between cavities 85 and 86 of the Starter Motor Relay connector
in the Fuse/Relay Block connector.
While observing the test light, attempt to start the engine.
Did the test light illuminate when turning the ignition switch to the Crank position?All
Ye s!Go To 3
No!Go To 8
242
DRIVEABILITY - DIESEL
TEST ACTION APPLICABILITY
3 Turn the ignition off.
Remove the Starter Motor Relay from the Fuse/Relay Block.
Using a 12-volt test light connected to ground, check the Ignition Switch Output
(Start) circuit in the Starter Motor Relay connector in the Fuse/Relay Block while
turning the ignition to the Crank/Start position.
Did the test light illuminate while turning the ignition to the Crank/Start position?All
Ye s!Go To 4
No!Repair the Ignition Switch Output (Start) circuit for an open.
Perform NO START VERIFICATION - VER-1.
4 Turn the ignition off.
Remove the Starter Motor Relay from the Fuse/Relay Block.
Install a substitute relay in place of the Starter Motor Relay.
Attempt to start the engine.
Does the engine crank?All
Ye s!Replace the Starter Motor Relay.
Perform NO START VERIFICATION - VER-1.
No!Go To 5
5 Turn the ignition off.
Remove the Starter Motor Relay from the Fuse/Relay Block.
Disconnect the Starter Motor Relay Output wire from the Starter Solenoid.
Connect the Starter Motor Relay Output wire (at the Starter) to ground.
Using a 12-volt test light connected to 12-volts, check the Starter Motor Relay Output
circuit at the Starter Motor Relay connector in the Fuse/Relay Block.
Does the test light illuminate brightly?All
Ye s!Go To 6
No!Repair the Starter Relay Output circuit for an open.
Perform NO START VERIFICATION - VER-1.
6 Using the Service Information, check the battery cables for high resistance.
Did either battery cable have a voltage drop greater than 0.2 volts?All
Ye s!Replace the battery cable(s).
Perform NO START VERIFICATION - VER-1.
No!Go To 7
7 Turn the ignition off.
Attempt to manually rotate the crankshaft 360É.
Is the crankshaft able to rotate 360É?All
Ye s!Replace the Starter Motor.
Perform NO START VERIFICATION - VER-1.
No!Repair the engine mechanical problem.
Perform NO START VERIFICATION - VER-1.
243
DRIVEABILITY - DIESEL
*ENGINE WILL NOT CRANK ÐContinued
TEST ACTION APPLICABILITY
8NOTE: The ECM must have proper power and ground connections for the
following tests to be valid. Refer to Checking the ECM Power and Grounds
in the symptom list.
Turn the ignition on.
With the DRBIIIt, read the ECM DTCs.
Does the DRBIIItdisplay any ECM DTCs?All
Ye s!Refer to symptom list for problems related to ECM DTC.
Perform NO START VERIFICATION - VER-1.
No!Go To 9
9 Turn the ignition on.
With the DRBIIIt, read the SKREEM DTCs.
Does the DRBIIItdisplay any SKREEM DTCs?All
Ye s!Refer to symptom list for problems related to SKREEM.
Perform NO START VERIFICATION - VER-1.
No!Go To 10
10 Turn the ignition on.
With the DRBIIIt, read the TCM DTCs.
Does the DRBIIItdisplay any TCM DTCs?All
Ye s!Refer to symptom list for problems related to TCM.
Perform NO START VERIFICATION - VER-1.
No!Go To 11
11 Perform the Checking the ECM Power and Grounds test.
Were any problems found?All
Ye s!Repair as necessary.
Perform NO START VERIFICATION - VER-1.
No!Go To 12
12 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Starter Motor Relay from the Fuse/Relay Block
Remove the Engine Control Relay from the Fuse Block No.1.
Using a jumper wire, connect Engine Control Relay connector cavities 30 and 87 in
the Fuse Block No.1.
Turn the ignition on.
Measure the voltage of the Starter Motor Relay Control circuit.
Is the voltage above 1.0 volt?All
Ye s!Repair the Starter Relay Control circuit for a short to voltage.
Perform NO START VERIFICATION - VER-1.
No!Go To 13
244
DRIVEABILITY - DIESEL
*ENGINE WILL NOT CRANK ÐContinued
TEST ACTION APPLICABILITY
13 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Starter Motor Relay from the Fuse/Relay Block.
Measure the resistance of the Starter Motor Relay Control circuit between the ECM
harness connector and the Fuse/Relay Block connector.
Measure the resistance of the Starter Motor Relay 12-volt Supply circuit between the
ECM harness connector and the Fuse/Relay Block connector.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Go To 14
No!Repair the Starter Motor Relay circuit(s) for an open.
Perform NO START VERIFICATION - VER-1.
14 Turn the ignition off.
Disconnect the ECM harness connectors.
Remove the Starter Motor Relay from the Fuse/Relay Block.
Measure the resistance between ground and the Starter Motor Relay Control circuit
at the Fuse/Relay Block connector.
Measure the resistance between ground and the Starter Motor Relay 12-volt Supply
circuit at the Fuse/Relay Block connector.
Is the resistance below 10.0 ohms for each measurement?All
Ye s!Replace and program the Engine Control Module in accordance
with the Service Information.
Perform NO START VERIFICATION - VER-1.
No!Repair the Starter Motor Relay circuit(s) for a short to ground.
Perform NO START VERIFICATION - VER-1.
245
DRIVEABILITY - DIESEL
*ENGINE WILL NOT CRANK ÐContinued
CONTROLLER ANTILOCK BRAKECAV CIRCUIT FUNCTION
1 12BR GROUND
2 12RD FUSED B(+)
3- -
4- -
5 14BR GROUND
6 14RD FUSED B(+)
7- -
8 20BK/DG SENSOR SIGNAL
9 20YL/WT SENSOR SIGNAL
10 20YL/RD SENSOR SIGNAL
11 18BL/BK K-ABS/SHIFTER ASSEMBLY
12 18BK LEFT FRONT WHEEL SPEED SENSOR (+)
13 - -
14 20WT LEFT REAR WHEEL SPEED SENSOR (+)
15 18BR RIGHT FRONT WHEEL SPEED SENSOR (-)
16 18BK RIGHT FRONT WHEEL SPEED SENSOR (+)
17 - -
18 - -
19 - -
20 20WT BRAKE SWITCH OUTPUT
21 20BR GROUND
22 - -
23 18BK/RD FUSED OPTIONAL EQUIPMENT RELAY OUTPUT
24 20DG/WT CAN C BUS (+)
25 20BR SENSOR GROUND
26 20WT/GY BRAKE PRESSURE SENSOR SIGNAL
27 18BK/BL TCS SWITCH (ASR) SENSE
28 18BR LEFT FRONT WHEEL SPEED SENSOR (-)
29 20BR LEFT REAR WHEEL SPEED SENSOR (-)
30 20BR RIGHT REAR WHEEL SPEED SENSOR (-)
31 20YL RIGHT REAR WHEEL SPEED SENSOR (+)
32 18BK/RD BRAKE LAMP SWITCH OUTPUT
33 - -
34 - -
35 - -
36 - -
37 - -
38 - -
39 20RD/BL POWER INPUT
40 20DG CAN C BUS (-)
41 20DG/YL SENSOR SIGNAL
42 20WT/RD 5 VOLT SUPPLY
CRANKCASE HEATER - BLACKCAV CIRCUIT FUNCTION
1 18BR (EXCEPT OBD) GROUND
1 18BK/RD (OBD) CRANKCASE HEATER SIGNAL
2 16BK/RD (EXCEPT OBD) FUSED ENGINE CONTROL RELAY OUTPUT
2 18BK/BR (OBD) CRANKCASE HEATER GROUND
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CONNECTOR PINOUTS
ENGINE CONTROL RELAY (FUSE BLOCK NO. 1)CAV CIRCUIT FUNCTION
30 INTERNAL FUSED B(+)
85 INTERNAL ENGINE CONTROL RELAY CONTROL
86 INTERNAL FUSED B(+)
87 INTERNAL ENGINE CONTROL RELAY OUTPUT
87A --
FUSES (FUSE BLOCK NO. 1)FUSE
NO.AMPS FUSED CIRCUIT FUNCTION
1- - -
2 10A 16WT FUSED HIGH BEAM SWITCH OUTPUT
3 10A 16WT FUSED HIGH BEAM SWITCH OUTPUT
4 10A 16WT/BL/RD FUSED IGNITION SWITCH OUTPUT (RUN-START)
5 10A 16BK/BL/WT FUSED IGNITION SWITCH OUTPUT (RUN-START)
6 20A INTERNAL FUSED IGNITION SWITCH OUTPUT (RUN-START)
7 15A 16BK/YL FUSED IGNITION SWITCH OUTPUT (RUN-START)
8 20A 16RD/YL FUSED B(+)
9 15A INTERNAL FUSED B(+)
10 10A 16GY/DG/RD HEADLAMP SWITCH OUTPUT
11 10A 16GY/BK FUSED LEFT LAMP RELAY OUTPUT
12 10A 18YL HEADLAMP SWITCH OUTPUT
13 10A 18YL HEADLAMP SWITCH OUTPUT
14 15A 16BK/YL/WT FOG LAMP RELAY SIGNAL
15 10A 16BK/RD FUSED IGNITION SWITCH OUTPUT (ACC-RUN-START)
16 15A 12BK/BL ENGINE CONTROL RELAY OUTPUT
17 15A 16BK/RD ENGINE CONTROL RELAY OUTPUT
18 15A 14BK FUSED IGNITION SWITCH OUTPUT (RUN-START)
19 15A 14RD/BK (OBD) FUSED B(+)
20 15A 16RD/BL FUSED B(+)
21 30A 12RD FUSED B(+)
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CONNECTOR PINOUTS