Page 514 of 4284

Symptom:
PARK LAMP OUTPUT 2 SHORT TO BATTERY
When Monitored and Set Condition:
PARK LAMP OUTPUT 2 SHORT TO BATTERY
When Monitored: Ignition on.
Set Condition: When a battery fault condition is present.
POSSIBLE CAUSES
INTERMITTENT CONDITION
PARK LAMP RELAY
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: Park Lamp Output 2 Short to BATTAll
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.
Remove and install a known good relay in place of the Park Lamp Relay.
Do the Park Lamps operate normally?All
Ye s®Replace the Park Lamp Relay.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 3
3 Turn the ignition off.
Remove the Park Lamp Relay from the IPM.
Remove the Front Control Module from the IPM.
Measure the voltage of the Park Lamp Relay Control circuit and ground.
Is the voltage above 1.0 volts?All
Ye s®Replace the Intelligent Power Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Front Control Module.
Perform BODY VERIFICATION TEST - VER 1.
485
EXTERIOR LIGHTING
Page 535 of 4284

Symptom:
RIGHT SIDE PARK LAMP OPEN
When Monitored and Set Condition:
RIGHT 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 #3
PARK LAMP OUTPUT CIRCUIT OPEN
PARK LAMP RELAY
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: Right 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 right 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.
506
EXTERIOR LIGHTING
Page 536 of 4284

TEST ACTION APPLICABILITY
3 Turn the ignition off.
Disconnect the right 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 #3.
Is the Fuse open?All
Ye s®Replace the Park Lamp Fuse #3.
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 above 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.
507
EXTERIOR LIGHTING
RIGHT SIDE PARK LAMP OPEN ÐContinued
Page 571 of 4284

Symptom List:
FRONT AND REAR BLOWER OUTPUT 1 OPEN
FRONT AND REAR BLOWER OUTPUT 2 OPEN
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be FRONT AND REAR BLOWER
OUTPUT 1 OPEN.
When Monitored and Set Condition:
FRONT AND REAR BLOWER OUTPUT 1 OPEN
When Monitored: Continuously.
Set Condition: If the FCM detects no voltage present on the Front/Rear Blower Motor
Relay Control circuit.
FRONT AND REAR BLOWER OUTPUT 2 OPEN
When Monitored: Continuously.
Set Condition: If the FCM detects no voltage present on the Front/Rear Blower Motor
Relay Control circuit.
POSSIBLE CAUSES
CHECK DTCS
B+ CIRCUIT OPEN
FRONT AND REAR BLOWER RELAYS OPEN
FRONT/REAR BLOWER MOTOR RELAY CONTROL CIRCUIT SHORTED TO GROUND
FRONT/REAR BLOWER MOTOR RELAY CONTROL CIRCUIT OPEN
FRONT CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
NOTE: If neither DTC will reset or is active, refer to the wiring diagrams
located in the service information to help isolate a possible intermittent
condition.
With the DRB, read the FCM DTC's.
Are both the Front/Rear Blower Output 1 Open and the Front/Rear Blower Output
2 Open DTC's set?All
Ye s®Go To 2
No®Replace the Front Control Module (FCM) in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
542
HEATING & A/C
Page 572 of 4284

TEST ACTION APPLICABILITY
2 Remove either the Front Blower Motor Relay or the Rear Blower Motor Relay, if
equipped, from the IPM.
Using a 12-volt test light connected to ground, probe cavity 86 of the blower relay
connector.
Is the test light illuminated?All
Ye s®Go To 3
No®Check the B+ feed to the Intelligent Power Module (IPM) for an
open. If OK, replace the IPM in accordance with the Service
Information.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Install a substitute relay in place of the existing Front Blower Motor Relay and the
existing Rear Blower Motor Relay, if equipped.
With the DRB, erase DTCs.
Turn the ignition off, wait 30 seconds, then turn the ignition on.
With the DRB, read DTCs.
Did these DTCs reset?All
Ye s®Go To 4
No®Replace the Front Blower Motor Relay and the Rear Blower
Motor Relay, if equipped.
Perform BODY VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Remove the Front Control Module from the IPM.
Remove the Front Blower Motor Relay and the Rear Blower Motor Relay, if equipped,
from the IPM.
Measure the resistance between ground and the Front/Rear Blower Motor Relay
Control circuit (FCM connector cavity 30).
Is the resistance below 5.0 ohms?All
Ye s®Replace the Intelligent Power Module (IPM) in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 5
5 Turn the ignition off.
Remove the Front Control Module from the IPM.
Remove the Front Blower Motor Relay from the IPM.
Measure the resistance of the Front/Rear Blower Motor Relay Control circuit
between the FCM connector cavity 30 and the Front Blower Motor Relay connector
cavity 85.
Is the resistance below 5.0 ohms?All
Ye s®Replace the Front Control Module (FCM) in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Intelligent Power Module (IPM) in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
543
HEATING & A/C
FRONT AND REAR BLOWER OUTPUT 1 OPEN ÐContinued
Page 573 of 4284

Symptom List:
FRONT AND REAR BLOWER OUTPUT 1 SHORT TO BATT
FRONT AND REAR BLOWER OUTPUT 2 SHORT TO BATT
Test Note: All symptoms listed above are diagnosed using the same tests.
The title for the tests will be FRONT AND REAR BLOWER
OUTPUT 1 SHORT TO BATT.
When Monitored and Set Condition:
FRONT AND REAR BLOWER OUTPUT 1 SHORT TO BATT
When Monitored: With the ignition on.
Set Condition: The FCM detects excessive current when attempting to close the Front/
Rear Blower Motor Relays.
FRONT AND REAR BLOWER OUTPUT 2 SHORT TO BATT
When Monitored: With the ignition on.
Set Condition: The FCM detects excessive current when attempting to close the Front/
Rear Blower Motor Relays.
POSSIBLE CAUSES
CHECK DTCS
FRONT BLOWER MOTOR RELAY SHORTED
REAR BLOWER MOTOR RELAY SHORTED
FRONT/REAR BLOWER MOTOR RELAY CONTROL CIRCUIT SHORTED TO BATTERY
FRONT CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
NOTE: If neither DTC will reset or is active, refer to the wiring diagrams
located in the service information to help isolate a possible intermittent
condition.
With the DRB, read the FCM DTC's.
Are both of these DTCs set?All
Ye s®Go To 2
No®Replace the Front Control Module (FCM) in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
544
HEATING & A/C
Page 574 of 4284

TEST ACTION APPLICABILITY
2 Turn the ignition off.
Install a substitute relay in place of the existing Front Blower Motor Relay.
With the DRB, erase DTCs.
Turn the ignition on.
With the DRB, read DTCs.
Did these DTCs reset?All
Yes, equipped with rear blower motor
Go To 3
Yes, not equipped with rear blower motor
Go To 4
No®Replace the original Front Blower Motor Relay.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Install a substitute relay in place of the existing Rear Blower Motor Relay.
With the DRB, erase DTCs.
Turn the ignition on.
With the DRB, read DTCs.
Did these DTCs reset?All
Ye s®Go To 4
No®Replace the original Rear Blower Motor Relay.
Perform BODY VERIFICATION TEST - VER 1.
4 Turn the ignition off.
Remove the Front Control Module from the IPM.
Remove the Front Blower Motor Relay and the Rear Blower Motor Relay, if equipped,
from the IPM.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Front Blower Motor Relay
connector cavity 85.
Is the test light illuminated?All
Ye s®Replace the Intelligent Power Module (IPM) in accordance with
the Service Information.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Front Control Module (FCM) in accordance with the
Service Information.
Perform BODY VERIFICATION TEST - VER 1.
545
HEATING & A/C
FRONT AND REAR BLOWER OUTPUT 1 SHORT TO BATT ÐContinued
Page 646 of 4284

Symptom:
ACCESSORY POWER OUTPUT #1 OPEN
When Monitored and Set Condition:
ACCESSORY POWER OUTPUT #1 OPEN
When Monitored: Continuously with the ignition on.
Set Condition: The FCM has detected an open in the Accessory Relay control circuit.
POSSIBLE CAUSES
FRONT CONTROL MODULE
FUSE & RELAY CENTER INTERNAL MALFUNCTION
ACCESSORY RELAY
FRONT CONTROL MODULE
INTERMITTENT CONDITION
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 both the ACCESSORY POWER OUTPUT OPEN trouble
codes?All
Ye s®Go To 2
No®Go To 3
2 Turn the ignition off.
Disconnect the Accessory Relay from the Fuse & Relay Center.
Connect a known good relay to the Accessory Relay location in the Fuse & Relay
Center.
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 both the ACCESSORY POWER OUTPUT OPEN trouble
codes?All
Ye s®Replace the Fuse and Relay Center.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the original Accessory Relay.
Perform BODY VERIFICATION TEST - VER 1.
617
INTELLIGENT POWER MODULE