Page 450 of 4284

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the TCM harness connector.
Remove the starter relay from the IPM.
Using a 12-volt test light connected to ground, probe the Ignition Switch Output
(Start) circuit.
Note: The light must illuminate brightly, if it does not light, or lights dimly,
the circuit must be repaired. If there is any doubt, compare the brightness
when testing the circuit, to the brightness when connected directly to the
battery positive post.
Observe the test light while momentarily turning the ignition switch to the Start
position.
Is the test light illuminated?All
Ye s®Go To 4
No®Repair the Ignition Switch Output (Start) circuit for an open.
Refer to the wiring diagrams located in the Service Information.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
Note: Reinstall the original Starter Relay.
4 Turn the ignition off.
Disconnect the TCM harness connector.
Using a 12-volt test light connected to ground, probe the Fused B(+) circuit.
Note: The light must illuminate brightly, if it does not light, or lights dimly,
the circuit must be repaired. If there is any doubt, compare the brightness
when testing the circuit, to the brightness when connected directly to the
battery positive post.
Is the test light illuminated?All
Ye s®Go To 5
No®Check IPM fuse #15 for an open. If OK, repair the Fused B(+)
circuit for an open. Refer to the wiring diagrams located in the
Service Information.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
5 Turn the ignition off.
Disconnect the TCM harness connector.
Using a 12-volt test light connected to 12-volts, probe each ground circuit in the TCM
connector.
NOTE: The light must illuminate brightly, if it does not light, or lights dimly,
the circuit must be repaired. If there is any doubt, compare the brightness
when testing the circuit, to the brightness when connected directly to the
battery negative post.
Is the light illuminated at all ground circuits?All
Ye s®Go To 6
No®Repair the Ground circuit(s) for an open. Check the main ground
connection to engine block and/or chassis. Refer to the wiring
diagrams located in the Service Information.
Perform 41TE TRANSMISSION VERIFICATION TEST - VER 1.
421
COMMUNICATION
*NO RESPONSE FROM TRANSMISSION CONTROL MODULE ÐContinued
Page 470 of 4284
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Install a known good relay in place of the Rear Window Defogger relay.
Turn the ignition on.
Attempt to operate the Rear Window Defogger.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DTC reset?All
Ye s®Go To 5
No®Replace the Rear Defogger Relay.
Perform BODY VERIFICATION TEST - VER 1.
5 Turn the ignition off.
Disconnect the Front Control Module from the Fuse and Relay Center.
Remove the Rear Window Defogger Relay.
Measure the resistance of the Rear Window Defogger Relay Control Circuit in the
Fuse and Relay Center.
Is the resistance below 5.0 ohms?All
Ye s®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Fuse and Relay Center.
Perform BODY VERIFICATION TEST - VER 1.
441
ELECTRICALLY HEATED SYSTEMS
EBL RUN ONLY RELAY OPEN ÐContinued
Page 471 of 4284

Symptom:
EBL RUN ONLY RELAY SHORTED TO BATTERY
When Monitored and Set Condition:
EBL RUN ONLY RELAY SHORTED TO BATTERY
When Monitored: Continuously with the ignition on.
Set Condition: The FCM has detected a short to battery voltage in the Rear Defogger
Relay control circuit.
POSSIBLE CAUSES
VERIFY ACTIVE DTC
FRONT CONTROL MODULE
INTELLIGENT POWER MODULE
REAR WINDOW DEFOGGER RELAY
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, erase the current Front Control Module DTC's.
Turn the ignition off, wait 10 seconds then turn the ignition on.
With the DRBIIIt, read the current Front Control Module DTC's.
Does the DRBIIItdisplay EBL RUN ONLY RELAY SHORTED TO BATTERY
trouble code?All
Ye s®Go To 2
No®The condition that caused this symptom is currently not present
at this time.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Install a known good relay in place of the Rear Window Defogger relay.
Turn the ignition on.
Attempt to operate the Rear Window Defogger.
With the DRBIIIt, read the current Front Control Module DTCs.
Did the DTC reset?All
Ye s®Go To 3
No®Replace the Rear Defogger Relay.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Remove the Rear Window Defogger Relay from the IPM.
Remove the Front Control Module from the IPM.
Measure the voltage of the Rear Window Relay Control circuit.
Is the voltage above 1.0 volts?All
Ye s®Replace the Fuse and Relay Center.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
442
ELECTRICALLY HEATED SYSTEMS
Page 475 of 4284

Symptom:
FRONT FOG LAMP RELAY OPEN
When Monitored and Set Condition:
FRONT FOG LAMP RELAY OPEN
When Monitored: Ignition On.
Set Condition: The IPM detects high current from the fog lamp relay control circuit.
POSSIBLE CAUSES
MISSING RELAY
OPEN FUSE
FOG LAMP RELAY
INTERMITTENT CONDITION
FOG LAMP RELAY CONTROL CIRCUIT OPEN
FRONT CONTROL MODULE
INTELLIGENT POWER MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, clear all IPM DTC's.
Turn the Fog Lamps on.
With the DRBIIIt, read the DTC information.
Does the DRBIIItread: Front Fog Lamp Relay Open?All
Ye s®Go To 2
No®Go To 5
2 Turn the ignition off.
Check the IPM to make certain the Fog Lamp Relay is present.
Is the Fog Lamp Relay present?All
Ye s®Go To 3
No®Replace the missing Fog Lamp Relay.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Install a known good relay in place of the fog lamp relay.
Turn the Fog Lamps On.
Do the Fog Lamps operate normally?All
Ye s®Replace the Fog Lamp Relay.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
446
EXTERIOR LIGHTING
Page 476 of 4284

TEST ACTION APPLICABILITY
4 Turn the ignition off
Remove the Fog Lamp Relay.
Measure the voltage of the Fused B+ circuit of the fog lamp relay.
Is the voltage above 10 volts?All
Ye s®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Intelligent Power Module.
Perform BODY VERIFICATION TEST - VER 1.
5 Turn the ignition off.
Check the IPM Fog Lamp fuse #1.
Is the fuse open?All
Ye s®Replace the open fuse.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 6
6 Turn the ignition off.
Disconnect the Front Control Module from the IPM.
Remove the Fog Lamp Relay.
Measure the resistance of the Fog Lamp Relay Control Circuit.
Is the resistance below 5.0 ohms?All
Ye s®The condition that caused the symptom is currently not present.
Inspect the related wiring for a possible intermittent condition.
Look for any chafed, pierced,pinched, or partially broken wires.
Perform BODY VERIFICATION TEST - VER 1.
No®Repair the Fog Lamp Relay Control Circuit.
Perform BODY VERIFICATION TEST - VER 1.
447
EXTERIOR LIGHTING
FRONT FOG LAMP RELAY OPEN ÐContinued
Page 507 of 4284

Symptom:
LEFT SIDE PARK LAMP OPEN
When Monitored and Set Condition:
LEFT SIDE PARK LAMP OPEN
When Monitored: Anytime the FCM is active.
Set Condition: When B+ voltage is below 10.0 volts.
POSSIBLE CAUSES
INTERMITTENT CONDITION
GROUND CIRCUIT
PARK LAMP
PARK LAMP FUSE #2
PARK LAMP RELAY
PARK LAMP OUTPUT CIRCUIT OPEN
FRONT CONTROL MODULE
INTELLIGENT POWER MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, clear all FCM DTC's.
Turn the Park Lamps on.
With the DRBIIIt, read the DTC information.
Does the DRBIIItread: Left Side Park Lamp Fuse Outage?All
Ye s®Go To 2
No®The condition that caused the symptom is currently not present.
Inspect the related wiring for a possible intermittent condition.
Look for any chafed, pierced,pinched, or partially broken wires.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off
Disconnect the left front Park Lamp harness connector.
Using a 12-volt test light connected to 12-volts, check the ground circuit.
Does the test light illuminate brightly?All
Ye s®Go To 3
No®Repair the Ground Circuit.
Perform BODY VERIFICATION TEST - VER 1.
478
EXTERIOR LIGHTING
Page 508 of 4284

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the left front park lamp connector.
Turn the ignition on.
Turn the Park Lamps on.
Using a 12-volt test light connected to ground, check the Park Lamp Output circuit.
Does the test light illuminate brightly?All
Ye s®Replace the Park Lamp.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
4 Turn the ignition off.
Check the IPM Park Lamp Fuse #2.
Is the Fuse open?All
Ye s®Replace the Park Lamp Fuse #2.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 5
5 Turn the ignition off.
Install a known good relay in place of the Park Lamp Relay.
Turn the Park Lamps on.
Do the Park Lamps operate normally?All
Ye s®Replace the Park Lamp Relay.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 6
6 Turn the ignition off.
Disconnect the IPM harness connector.
Measure the resistance of the Park Lamp Output Circuit to ground.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Park Lamp Output Circuit for an open condition.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 7
7 Turn the ignition off.
Remove the Park Lamp Relay.
Measure the voltage of the Fused B+ circuit of the Park Lamp Relay.
Is the voltage above 10.0 volts?All
Ye s®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Intelligent Power Module.
Perform BODY VERIFICATION TEST - VER 1.
479
EXTERIOR LIGHTING
LEFT SIDE PARK LAMP OPEN ÐContinued
Page 509 of 4284

Symptom:
PARK LAMP OUTPUT 1 OPEN
When Monitored and Set Condition:
PARK LAMP OUTPUT 1 OPEN
When Monitored: Ignition on.
Set Condition: The IPM detects high current from the Park Lamp Relay Control circuit.
POSSIBLE CAUSES
MISSING RELAY
OPEN FUSE
PARK LAMP RELAY
INTERMITTENT CONDITION
RIGHT FRONT FUSED PARK LAMP RELAY OUTPUT CIRCUIT OPEN
FRONT CONTROL MODULE
INTELLIGENT POWER MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, clear all IPM DTC's.
Turn the Park Lamps on.
With the DRBIIIt, read the DTC information.
Does the DRBIIItread: Park Lamp Output 1 Open?All
Ye s®Go To 2
No®Go To 6
2 Turn the ignition off.
Check the IPM to make certain the Park Lamp Relay is present.
Is the Park Lamp Relay present?All
Ye s®Go To 3
No®Replace the missing Park Lamp Relay.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Check the IPM Park Lamp fuse #3.
Is the fuse open?All
Ye s®Replace the open fuse.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
480
EXTERIOR LIGHTING