Page 665 of 4284

Symptom:
DOME SWITCH INPUT SHORT
When Monitored and Set Condition:
DOME SWITCH INPUT SHORT
When Monitored: Dome Lamps Off.
Set Condition: When Voltage has gone below 0.196 volts for 62.5 msec.
POSSIBLE CAUSES
PANEL LAMPS DIMMER SIGNAL CIRCUIT SHORT
PANEL LAMPS DIMMER SIGNAL CIRCUIT SHORT TO GROUND
HEADLAMP SWITCH MUX RETURN CIRCUIT SHORT TO GROUND
HEADLAMP SWITCH
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition off.
Disconnect the Body Control Module C5 connector.
Measure the resistance between the Panel Lamps Dimmer Signal Circuit and the
Headlamp Switch MUX Return Circuit.
Is either circuit below 1000 ohms?All
Ye s®Go To 2
No®Repair the Panel Lamps Dimmer Signal Circuit shorted to the
Headlamp Switch MUX Return Circuit.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Disconnect the Headlamp Switch harness connector.
Disconnect the Body Control Module C5 connector.
Measure the resistance of the Panel Lamps Dimmer Signal Circuit to ground.
Is the resistance below 1000 ohms?All
Ye s®Repair the Panel Lamps Dimmer Signal Circuit for a short to
ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 3
3 Turn the ignition off.
Disconnect the Headlamp Switch harness connector.
Disconnect the Body Control Module C5 harness connector.
Measure the resistance of the Headlamp Switch MUX Return Circuit to ground.
Is the resistance below 1000 ohms?All
Ye s®Repair the Headlamp Switch MUX Return Circuit for a short to
ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 4
636
INTERIOR LIGHTING
Page 666 of 4284
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Headlamp Switch harness connector.
Measure the resistance of the Panel Lamps Dimmer Signal Circuit and the
Headlamp Switch MUX Return Circuit to ground.
Is the resistance of either circuit below 1000 ohms?All
Ye s®Replace the Headlamp Switch.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
637
INTERIOR LIGHTING
DOME SWITCH INPUT SHORT ÐContinued
Page 667 of 4284

Symptom:
FRONT COURTESY LAMPS OUTPUT SHORT
When Monitored and Set Condition:
FRONT COURTESY LAMPS OUTPUT SHORT
When Monitored: Anytime the Body Control Module is active.
Set Condition: When the voltage of the Headlamp Switch MUX Return Circuit falls below
5.0 volts for 10 seconds.
POSSIBLE CAUSES
HEALAMP SWITCH MUX RETURN CIRCUIT SHORT TO GROUND
COURTESY LAMPS DRIVER CIRCUIT OPEN
PANEL LAMPS DIMMER SIGNAL CIRCUIT OPEN
BODY CONTROL MODULE
HEADLAMP SWITCH
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, clear all BCM DTC's.
Turn the courtesy lamps on.
With the DRBIIIt, read the DTC information.
Does the DRBIIItread: Front Courtesy Lamps Output Short?All
Ye s®Repair the Headlamp Switch MUX Return Circuit for a short to
ground condition.
Perform BODY VERIFICATION TEST - VER 1.
No®Go To 2
2 Turn the ignition off.
Remove and inspect the inoperative courtesy lamp bulb.
With the DRBIIIt, measure the resistance of the Courtesy Lamps Driver- Dome
Circuit.
Is the resistance above 1000 ohms?All
Ye s®Go To 3
No®Repair the Open Courtesy Lamps Driver-Dome Circuit and re-
place the bulb.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the Headlamp Switch harness connector.
Disconnect the Body Control Module harness connector.
Measure the resistance of the Panel Lamps Dimmer Signal Circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 4
No®Repair the Open Panel Lamps Dimmer Signal Circuit.
Perform BODY VERIFICATION TEST - VER 1.
638
INTERIOR LIGHTING
Page 668 of 4284
TEST ACTION APPLICABILITY
4 Turn the ignition off.
Disconnect the Headlamp Switch harness connector.
Disconnect the Body Control Module harness connector.
Measure the voltage of the Headlamp Switch MUX Return Circuit.
Is the voltage below 5.0 volts?All
Ye s®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Headlamp Switch.
Perform BODY VERIFICATION TEST - VER 1.
639
INTERIOR LIGHTING
FRONT COURTESY LAMPS OUTPUT SHORT ÐContinued
Page 669 of 4284

Symptom:
HALO/DOOR/LIFTGATE LAMP OUTPUT SHORT
POSSIBLE CAUSES
COURTESY LAMPS DRIVER - DOOR CIRCUIT SHORT TO GROUND
COURTESY LAMPS DRIVER - LIFTGATE CIRCUIT SHORT TO GROUND
BODY CONTROL MODULE
HALO LAMP DRIVER CIRCUIT SHORT TO GROUND
TEST ACTION APPLICABILITY
1 With the DRBIIIt, clear all present DTC's.
Open the Drivers and Front Passenger door.
With the DRBIIIt, read the DTC information.
Does the DRBIIItread: Halo/Door/Liftgate Lamp Output Short?All
Ye s®Go To 2
No®Repair the Courtesy Lamps Driver - Door Circuit for a short to
ground.
Perform BODY VERIFICATION TEST - VER 1.
2 With the DRBIIIt, clear all present DTC's
Open the Liftgate.
With the DRBIIIt, read the DTC information.
Does the DRBIIItread: Halo/Door/Liftgate Lamp Output Short?All
Ye s®Go To 3
No®Repair the Courtesy Lamps Driver - Liftgate Circuit for a short
condition.
Perform BODY VERIFICATION TEST - VER 1.
3 Turn the ignition off.
Disconnect the Body Control Module harness connector C4.
Measure the resistance of the Halo Lamp Driver Circuit.
Is the resistance below 5.0 ohms?All
Ye s®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Repair the Halo Lamp Driver Circuit for a short to ground.
Perform BODY VERIFICATION TEST - VER 1.
640
INTERIOR LIGHTING
Page 670 of 4284

Symptom:
READING LAMP OUTPUT SHORT
When Monitored and Set Condition:
READING LAMP OUTPUT SHORT
When Monitored: Anytime the Body Control Module is active.
Set Condition: When output voltage status is LOW.
POSSIBLE CAUSES
READING LAMPS DRIVER CIRCUIT SHORT
COURTESY LAMPS DRIVER READING LAMPS CIRCUIT SHORT TO GROUND
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRBIIIt, clear all BCM DTC's.
Turn the reading lamps on.
With the DRBIIIt, read the DTC information.
Does then DRBIIItdisplay : Reading Lamps Output Short?All
Ye s®Go To 2
No®Repair the Reading Lamps Driver Circuit for a short condition.
Perform BODY VERIFICATION TEST - VER 1.
2 Turn the ignition off.
Disconnect the Body Control Module C2 harness connector
Measure the resistance of the Courtesy Lamps Driver Reading Lamps Circuit.
Is the resistance below 5.0 ohms?All
Ye s®Repair the Courtesy Lamps Driver Reading Lamps Circuit for a
short to ground.
Perform BODY VERIFICATION TEST - VER 1.
No®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
641
INTERIOR LIGHTING
Page 671 of 4284

Symptom:
BCM MESSAGE NOT RECEIVED
When Monitored and Set Condition:
BCM MESSAGE NOT RECEIVED
When Monitored: Continuously when the PCI bus is active.
Set Condition: If the Memory Seat Mirror Module does receive this Bus message from the
BCM. Code will remain for 50 ignition cycles.
POSSIBLE CAUSES
BCM RESPONSE
STORED CODE/PCI BUS COMMUNICATION PROBLEMS
MEMORY SEAT MIRROR MODULE
INTERMITTENT PROBLEM
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIItselect Body Control Module.
Is there a response from the Body Control Module?All
Ye s®Go To 2
No®Refer to symptom *NO RESPONSE FROM BODY CONTROL
MODULE in the COMMUNICATION category
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
2 With the DRBIIIt, erase the DTC from Memory Seat Mirror Module.
Turn the ignition switch to the Off position then start the engine and let run for one
minute.
Now be sure that there is still communication with the Body Control module, if not
repair as necessary.
With the DRB check for the same DTC to reset in the MSMM.
Did the same DTC reset?All
Ye s®Go To 3
No®Test complete.
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
3NOTE: Visually inspect the related wiring harness including the PCI bus
wire. Look for any chafed, pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?All
No®Replace the Memory Seat Mirror Module.
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
Ye s®Repair as necessary.
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
642
MEMORY SEAT
Page 672 of 4284

Symptom:
CHARGING VOLTAGE HIGH MESSAGE
When Monitored and Set Condition:
CHARGING VOLTAGE HIGH MESSAGE
When Monitored: During cranking or with the engine running.
Set Condition: When the Memory Seat Mirror Module receives three high charging
system voltage messages above 15.94 volts over the PCI Bus. Code will remain for 50
ignition cycles.
POSSIBLE CAUSES
PCM TROUBLE CODES
STORED CODE COMMUNICATION PROBLEMS
MEMORY SEAT MIRROR MODULE
INTERMITTENT PROBLEM
TEST ACTION APPLICABILITY
1 Turn ignition on.
With the DRBIIItread Engine DTCs.
Is the DTC P1594 Charging System Voltage Too High set in the Power Control
Module?All
Ye s®Refer to symptom *P1594-CHARGING SYSTEM VOLTAGE TOO
HIGH in the CHARGING category
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
No®Go To 2
2 With the DRBIIIt, erase the DTC from Memory Seat Mirror Module.
Turn the ignition switch to the Off position then start the engine and let run for one
minute.
With the DRB check for the same DTC to reset in the MSMM.
Did the same DTC reset?All
Ye s®Go To 3
No®Test complete.
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
3Note: Visually inspect the related wiring harness. Look for any chafed,
pierced, pinched, or partially broken wires.
Note: Visually inspect the related wiring harness connectors. Look for
broken, bent, pushed out, or corroded terminals.
Note: Refer to any technical service bulletins that may apply.
Were any problems found?All
No®Replace the Memory Seat Mirror Module.
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
Ye s®Repair as necessary.
Perform MEMORY SYSTEM VERIFICATION TEST - VER 1.
643
MEMORY SEAT