SECTION 9B
LIGHTING SYSTEMS
Caution : Disconnect the negative battery cable before removing or installing any electrical unit when atool or equipment could easily come in contact with exposed electrical terminals. Disconnecting this cablewill help prevent personal injury and damage to the vehicle. The ignition must also be in LOCK unlessotherwise noted.
SPECIFICATIONS
Bulb Usage Chart
Bulb | Watt x Q'ty |
Front | 1 | Headlamp (High) | 55/00W x 2 |
2 | Headlamp (Low) | 55/00W x 2 |
3 | Parking Lamp | 21/05W x 2 |
4 | Turn Signal Lamp | 21/00W x 2 |
5 | Fog Lamp | 35/00W x 2 |
6 | Mirror Turn Signal Lamp | LED type 5 x 2 |
7 | Side Turrn Signal Lamp | 5/00W x 2 |
Rear | 8 | Turn Signal Lamp | 21/00W x 2 |
9 | Brake/Tail Lamp | 21/05W x 2 |
10 | Backup Lamp | 16/00W x 2 |
11 | Fog lamp | 21/00W x 2 |
12 | Center High Mounted Stop Lamp | 5/00W x1 |
13 | Licence Plate Lamp | 5/00W x 2 |
Interior | 14 | Room Lamp | 10/00W x 2 |
15 | Map Lamp | 10/00W x 2 |
16 | Front Door Step Lamp | 5/00W x 2 |
17 | Instrument Compartment Lamp | 10/00W x 1 |
Fastener Tightening Specifications
Application | N•m | Lb-Ft | Lb-In |
Fog Lamp Assembly Nuts | 3 | - | 27 |
Front Door Trim Panel Screws | 3 | - | 27 |
Headlamp Assembly Nuts | 7 | - | 62 |
Map Lamp Screws | 3 | - | 27 |
Room Lamp Screws | 3 | - | 27 |
License Plate Lamp Assembly Screws | 4 | - | 35 |
Rear Combination Lamp Assembly Screws | 2.5 | - | 22 |
Steering Column Trim Cover Screws | 3 | - | 22 |
Steering Column Bolts and Nuts | 22 | 16 | - |
SCHEMATIC AND ROUTING DIAGRAMS
Head Lamps Circuit
1) W/O Head Lamp Leveling
2) W/ Head Lamp Leveling
Head Lamps Switch Circuit
1) W/O Auto Light
2) W/ Auto Light
Hazard and Turn Signal Lamps Circuit
Parking and Tail Lamps Circuit
Fog Lamps Circuit
Courtesy Lamps Circuit
Stop and Backup Lamps Circuit
X - BCM Circuit
DIAGNOSIS
Symptoms -Lighting Systems
Important : The following steps must be completed before using the symptoms tables.
- Perform the Diagnostic System Check before using the symptom tables in order to verify that all of the following are true:
- There are no DTCs set.
- The control modules can communicate via the serial data link.
- Review the system operation in order to familiarize yourself with the system functions.
Visual/Physical Inspection
Several of the symptom procedures ask for a careful visual/physical check. This step is extremely important-it could lead to correcting a problem without further checks and can save valuable time. These checks include the following:
- Inspect for aftermarket devices which could affect the operation of the Lighting System.
- Inspect the easily accessible or visible system components and harness connectors for obvious damage or conditions which could cause the symptom.
- If only one lamp is inoperative, inspect and repair a poor connection or an open in the power feed or ground circuit before replacing the light bulb.
Intermittent
Backup Lamps Always On
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Place the gear selector in park or neutral.
Do the backup lamps illuminate? | - | Go to Step 3 | |
| 3 | Disconnect the park neutral position switch. Are the backup lamps illuminated? | - | Go to Step 4 | Go to Step 5 |
| 4 | Repair the short to battery positive voltage in the backup lamp supply voltage circuit. Did you complete the repair? | - | Go to Step 6 | - |
| 5 | Replace the switch. Did you complete the replacement? | - | Go to Step 6 | - |
| 6 | Operate the system in order to verify the repair. Did you correct the condition? Did you complete the replacement? | - | System OK | Go to Step 3 |
Backup Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Apply the park brake.
- Place the gear selector in the REVERSE position.
Do both backup lamps illuminate? | - | | Go to Step 3 |
| 3 | Is only one lamp inoperative? | - | Go to Step 4 | Go to Step 5 |
| 4 | - Disconnect the inoperative backup lamp connector.
- Probe the backup lamp supply voltage circuit of the backup lamp connector with a test lamp that is connected to a good ground.
Does the test lamp illuminate? | - | Go to Step 8 | Go to Step 9 |
| 5 | - Turn OFF the ignition.
- Disconnect the park neutral position switch connector.
- Turn ON the ignition, with the engine OFF.
- Probe the battery positive voltage circuit of the connector with a test lamp that is connected to a good ground.
Does the test lamp illuminate? | - | Go to Step 6 | Go to Step 10 |
| 6 | - Turn OFF the ignition.
- Connect a 10-amp fused jumper wire between the battery positive voltage circuit of the switch and the backup lamp supply voltage circuit of the switch.
Do the backup lamps illuminate? | - | Go to Step 7 | Go to Step 11 |
| 7 | Inspect for poor connections at the harness connector of the switch. Did you find and correct the condition? | - | Go to Step 13 | Go to Step 12 |
| 8 | Repair an open or high resistance in the ground circuit of the inoperative backup lamp. Refer to relating circuit. Did you complete the repair? | - | Go to Step 13 | - |
| 9 | Repair an open or high resistance in the backup lamp supply voltage circuit of the inoperative backup lamp. Did you complete the repair? | - | Go to Step 13 | - |
| 10 | Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the switch. Did you complete the repair? | - | Go to Step 13 | - |
| 11 | Repair an open or high resistance in the backup lamp supply voltage circuit between the switch and the backup lamps. Did you complete the repair? | - | Go to Step 13 | - |
| 12 | Replace the switch. Did you complete the replacement? | - | Go to Step 13 | - |
| 13 | Operate the system in order to verify the repair. Did you correct the condition? | - | Go to Step 13 | Go to Step 2 |
Courtesy Lamps Always On
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Ensure the front dome lamp switch is in the OFF position.
- Close all of the vehicle doors.
- Place the front dome lamp switch in the DOOR position.
- Wait 30 seconds.
Do the courtesy lamps operate as expected? | - | | Go to Step 3 |
| 3 | Do the courtesy lamps remain on with the front dome lamp switch in the OFF position? | - | Go to Step 7 | Go to Step 4 |
| 4 | - Ensure the front dome lamp switch is in the DOOR position.
- Close all of the vehicle doors.
- Use the scan tool in order to command the courtesy lamps OFF.
Do the courtesy lamps turn OFF when commanded? | - | Go to Step 5 | Go to Step 8 |
| 5 | - Close all of the vehicle doors.
- With a scan tool, observe the Driver Door Switch, Passenger Door Switch, and the Liftgate Ajar Switch parameters in the data list.
Does the scan tool display that all parameters are High? | - | Go to Step 14 | Go to Step 6 |
| 6 | Does the scan tool display that the Passenger Door Switch parameter is Low? | - | Go to Step 10 | Go to Step 9 |
| 7 | Disconnect the front dome lamp switch. Is the rear courtesy lamp illuminated? | - | Go to Step 15 | Go to Step 13 |
| 8 | Test the courtesy lamps switch signal circuit for a short to ground. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 14 |
| 9 | While monitoring the parameters, disconnect the connector of the switch that indicates a Low parameter. Does the scan tool display a parameter change to High when a switch is disconnected? | - | Go to Step 17 | Go to Step 11 |
| 10 | While monitoring the parameter, disconnect each passenger door jamb switch one at a time. Does the scan tool display a parameter change to High when one of the passenger door jamb switches is disconnected? | - | Go to Step 17 | Go to Step 12 |
| 11 | Test the ajar switch signal circuit for a short to ground. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 14 |
| 12 | Test the passenger door ajar switch signal circuit for a short to ground. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 14 |
| 13 | Inspect for poor connections at the harness connector of the Map lamp switch. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 14 | Inspect for poor connections at the harness connector of the body control module (BCM). Did you find and correct the condition? | - | Go to Step 19 | Go to Step 18 |
| 15 | Repair the ground circuit of the rear dome lamp for a short to ground. Did you complete the repair? | - | Go to Step 19 | - |
| 16 | Replace the Map lamp switch. Did you complete the replacement? | - | Go to Step 19 | - |
| 17 | Replace the inoperative ajar switch. Did you complete the replacement? | - | Go to Step 19 | - |
| 18 | Did you complete the replacement? | - | Go to Step 19 | - |
| 19 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 2 |
Courtesy Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Observe the courtesy lamps.
- Open and close all of the vehicle doors.
- Place the courtesy lamp switch in the ON position.
Do the courtesy lamps illuminate as expected? | - | | Go to Step 3 |
| 3 | Is only one courtesy lamp inoperative? | - | Go to Step 4 | Go to Step 5 |
| 4 | Test the voltage supply and ground circuits of the inoperative courtesy lamp for an open or high resistance. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 19 |
| 5 | Are all courtesy lamps inoperative at all times? | - | Go to Step 6 | Go to Step 7 |
| 6 | Test the courtesy lamp supply voltage and battery positive voltage circuits of the body control module (BCM) for an open, high resistance, or short to ground. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 17 |
| 7 | Are the courtesy lamps inoperative from the front dome lamp switch only? | - | Go to Step 8 | Go to Step 9 |
| 8 | Test the ground circuit of the front dome lamp switch for an open or high resistance. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 16 |
| 9 | Are the courtesy lamps inoperative from all doors and the liftgate? | - | Go to Step 10 | Go to Step 12 |
| 10 | - Open the doors.
- Connect a test lamp between the courtesy lamp low control circuit of the front dome lamp connector and battery positive voltage.
Does the test lamp illuminate? | - | Go to Step 16 | Go to Step 11 |
| 11 | Test the low control circuit of the BCM for an open or high resistance. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 17 |
| 12 | - With the scan tool, observe the parameter of the door that does not illuminate the courtesy lamps using the following:
- DRIVER DOOR SWITCH
- PASS DOOR SWITCH
- LIFTGATE AJAR SWITCH
Does the parameter switch from HIGH to LOW as expected? | - | Go to Step 17 | Go to Step 13 |
| 13 | - Close all doors that illuminate the courtesy lamps.
- Disconnect the inoperative door ajar switch connector.
- Connect a 3-amp fused jumper wire between the signal circuit of the connector and a good ground.
Do the courtesy lamps illuminate? | - | Go to Step 15 | Go to Step 14 |
| 14 | Test the signal circuit of the switch for an open or high resistance. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 17 |
| 15 | Test the ground circuit of the switch for an open or high resistance. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 18 |
| 16 | Inspect for poor connections at the harness connector of the front courtesy lamp assembly. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 20 |
| 17 | Inspect for poor connections at the harness connector of the BCM. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 21 |
| 18 | Inspect for poor connections at the harness connector of the inoperative switch. Did you find and correct the condition? | - | Go to Step 23 | Go to Step 22 |
| 19 | Replace the bulb. Did you complete the replacement? | - | Go to Step 23 | - |
| 20 | Replace the bulb or lamp assembly. Did you complete the replacement? | - | Go to Step 23 | - |
| 21 | Did you complete the replacement? | - | Go to Step 23 | - |
| 22 | Replace the inoperative switch. Did you complete the replacement? | - | Go to Step 23 | - |
| 23 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Daytime Running Lamps (DRL) Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Ensure that the ambient light sensor is not covered and is receiving daylight conditions.
- Place the headlamp switch in the AUTO position.
- Block the wheels.
- Ensure the parking brake is disengaged.
- Place the transaxle in neutral.
Do the daytime running lamps (DRL) illuminate? | - | | Go to Step 3 |
| 3 | - Turn ON the ignition, with the engine OFF.
- With the scan tool, command the DRL ON.
Do the low beam headlamps illuminate at low intensity? | - | Go to Step 4 | Go to Step 6 |
| 4 | Test the DRL ambient light sensor signal and the low ref circuits of the body control module (BCM) for a short to voltage, short to ground, open or high resistance. Did you find and correct the condition? | - | Go to Step 9 | Go to Step 5 |
| 5 | Inspect for poor connections at the harness connector of the ambient light sensor. Did you find and correct the condition? | - | Go to Step 9 | Go to Step 7 |
| 6 | Inspect for poor connections at the harness connector of the BCM. Did you find and correct the condition? | - | Go to Step 9 | Go to Step 8 |
| 7 | Replace the ambient light sensor. Did you complete the replacement? | - | Go to Step 9 | - |
| 8 | Did you find and correct the condition? | - | Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 2 |
Room Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | Place the room lamp switch in the ON position. Does the room lamp illuminate? | - | | Go to Step 3 |
| 3 | - Disconnect the room lamp assembly.
- Probe the courtesy lamp supply voltage circuit with a test lamp that is connected to a good ground.
Does the test lamp illuminate? | - | Go to Step 4 | Go to Step 6 |
| 4 | Connect the test lamp between the courtesy lamp supply voltage circuit and the courtesy lamp low control circuit. Does the test lamp illuminate? | - | Go to Step 5 | Go to Step 7 |
| 5 | Inspect for poor connections at the harness connector of the room lamp assembly. Did you find and correct the condition? | - | Go to Step 9 | Go to Step 8 |
| 6 | Repair an open, high resistance in the courtesy lamp supply voltage circuit. Did you complete the repair? | - | Go to Step 9 | - |
| 7 | Repair an open or high resistance in the courtesy lamp low control circuit. Did you complete the repair? | - | Go to Step 9 | - |
| 8 | Replace the room lamp assembly. Did you complete the replacement? | - | Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Fog Lamps Always On
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Place the fog lamp switch in the OFF position.
- Place the headlamp switch in the ON( AUTO) position.
Do the fog lamps remain illuminated? | - | Go to Step 3 | |
| 3 | Disconnect the fog lamp relay. Did the fog lamps turn OFF? | - | Go to Step 4 | Go to Step 6 |
| 4 | Test the fog lamp relay control circuit for a short to ground. Did you find and correct the condition? | - | Go to Step 8 | Go to Step 5 |
| 5 | Inspect for poor connections at the fog lamp relay. Did you find and correct the condition? | - | Go to Step 8 | Go to Step 7 |
| 6 | Repair a short to voltage in the front fog lamp supply voltage circuit. Did you complete the repair? | - | Go to Step 8 | - |
| 7 | Replace the fog lamp relay. Did you complete the replacement? | - | Go to Step 8 | - |
| 8 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Fog Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Place the headlamp switch in the headlamp ON position.
- Place the fog lamp switch in the ON position.
Do both fog lamps illuminate? | - | | Go to Step 3 |
| 3 | Is only one lamp inoperative? | - | Go to Step 4 | Go to Step 6 |
| 4 | Test the front fog lamp supply voltage circuit of the inoperative lamp for an open or high resistance. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 5 |
| 5 | Test the ground circuit of the inoperative lamp for an open or high resistance. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 15 |
| 6 | With a scan tool, command the fog lamps ON. Do the fog lamps illuminate? | - | Go to Step 9 | Go to Step 7 |
| 7 | - Disconnect the fog lamps relay.
- Probe the coil side voltage supply circuit of the fog lamp relay with a test lamp that is connected to a good ground.
Does the test lamp illuminate? | - | Go to Step 8 | Go to Step 17 |
| 8 | Probe the fog lamp relay control circuit of the fog lamp relay with a test lamp that is connected to battery positive voltage. Does the test lamp illuminate? | - | Go to Step 16 | Go to Step 12 |
| 9 | - Disconnect the fog lamp switch.
- Momentarily connect a 3-amp fused jumper wire between the front fog lamp switch signal circuit of the switch and battery positive voltage.
Do the fog lamps illuminate? | - | Go to Step 10 | Go to Step 11 |
| 10 | Test the ignition 1 voltage circuit of the fog lamp switch for an open, high resistance or short to ground. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 13 |
| 11 | Test the front fog lamp switch signal circuit for an open, high resistance or short to ground. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 14 |
| 12 | Test the fog lamp relay control circuit for an open or high resistance. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 14 |
| 13 | Inspect for poor connections at the harness connector of the fog lamp switch. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 19 |
| 14 | Did you find and correct the condition? | - | Go to Step 22 | Go to Step 20 |
| 15 | Inspect for poor connections at the harness connector of the inoperative fog lamp. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 18 |
| 16 | Inspect for poor connections at the fog lamp relay. Did you find and correct the condition? | - | Go to Step 22 | Go to Step 21 |
| 17 | Repair an open, high resistance, or short to ground in the coil side voltage supply circuit of the fog lamp relay. Did you complete the repair? | - | Go to Step 22 | - |
| 18 | Replace the bulb or lamp assembly. Did you complete the replacement? | - | Go to Step 22 | - |
| 19 | Replace the fog lamp switch. Did you complete the replacement? | - | Go to Step 22 | - |
| 20 | Did you complete the replacement? | - | Go to Step 22 | - |
| 21 | Replace the fog lamp relay. Did you complete the replacement? | - | Go to Step 22 | - |
| 22 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Hazard Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Place the hazard lamp switch to the ON position.
Do the hazard flashers operate correctly? | - | | Go to Step 3 |
| 3 | - Turn ON the ignition, with the engine OFF.
- Operate the left and right turn signals.
Does at least one left and one right turn signal lamp operate correctly, including the turn indicators? | - | Go to Step 4 | Check the DTC list |
| 4 | - Turn ON the hazard switch.
- Back probe the turn/hazard module signal circuit at the hazard switch connector with a test light that is connected to a good ground.
Does the test lamp flash ON and OFF? | - | Go to Step 8 | Go to Step 5 |
| 5 | - Turn ON the hazard switch.
- With the hazard switch ON, back probe the turn/hazard relay control circuit at the hazard switch connector with a test light that is connected to a good ground.
Does the test lamp illuminate? | - | Go to Step 6 | Go to Step 7 |
| 6 | Test the turn/hazard module signal circuit of the hazard switch for an open or high resistance between S200 and the hazard switch. Did you find and correct the condition? | - | Go to Step 12 | Go to Step 9 |
| 7 | Test the battery positive voltage circuit of the hazard switch for an open, high resistance or a short to ground. Did you find and correct the condition? | - | Go to Step 12 | - |
| 8 | Inspect for poor connections at the harness connector of the hazard switch. Did you find and correct the condition? | - | Go to Step 12 | Go to Step 10 |
| 9 | Inspect for poor connections at the harness connector of the turn signal relay. Did you find and correct the condition? | - | Go to Step 12 | Go to Step 11 |
| 10 | Replace the hazard switch. Did you complete the replacement? | - | Go to Step 12 | - |
| 11 | Replace the turn signal relay. Did you complete the replacement? | - | Go to Step 12 | - |
| 12 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Headlamps Inoperative -High Beams
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Place the headlamp switch in the headlamps ON position.
- Place the headlamp dimmer switch in the HIGH BEAM position.
Do the high beam headlamps illuminate? | - | | Go to Step 3 |
| 3 | Inspect for poor connections at the harness connector of the headlamp switch. Did you find and correct the condition? | - | Go to Step 5 | Go to Step 4 |
| 4 | Replace the headlamp switch. Did you complete the replacement? | - | Go to Step 5 | - |
| 5 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Headlamps Inoperative -Low Beams
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Place the headlamp switch in the headlamps ON position.
- Place the headlamp dimmer switch in the LOW BEAM position.
Do the low beam headlamps illuminate? | - | | Go to Step 3 |
| 3 | Inspect for poor connections at the harness connector of the headlamp switch. Did you find and correct the condition? | - | Go to Step 5 | Go to Step 4 |
| 4 | Replace the headlamp switch. Did you complete the replacement? | - | Go to Step 5 | - |
| 5 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Headlamps Inoperative -Low and High Beams
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Place the headlamp switch in the headlamps ON position.
- Place the headlamp dimmer switch in the LOW BEAM position.
- Observe the headlamps.
- Place the headlamp dimmer switch in the HIGH BEAM position.
- Observe the headlamps.
Do both the low and high beam headlamps illuminate? | - | | Go to Step 3 |
| 3 | Test the headlamp ground circuit of the headlamp switch for an open or high resistance. Did you find and correct the condition? | - | Go to Step 6 | Go to Step 4 |
| 4 | Inspect for poor connections at the harness connector of the headlamp switch. Did you find and correct the condition? | - | Go to Step 6 | Go to Step 5 |
| 5 | Replace the headlamp switch. Did you complete the replacement? | - | Go to Step 6 | - |
| 6 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Headlamps Inoperative -Flash to Pass
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Place the headlamp switch in the headlamps ON position.
- Place the multifunction lever in the FLASH TO PASS position.
Do the high beam headlamps illuminate? | - | | Go to Step 3 |
| 3 | Inspect for poor connections at the harness connector of the headlamp switch. Did you find and correct the condition? | - | Go to Step 5 | Go to Step 4 |
| 4 | Replace the headlamp switch. Did you complete the repair? | - | Go to Step 5 | - |
| 5 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Illuminated Entry Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn OFF the ignition.
- Lock all of the vehicle doors.
- Close all of the vehicle doors.
- Wait 20 seconds.
- Press the unlock button on the remote keyless entry transmitter.
Do the courtesy lamps illuminate? | - | | Go to Step 3 |
| 3 | Does the driver door unlock? | - | Go to Step 4 | |
| 4 | Did you complete the replacement? | - | Go to Step 5 | - |
| 5 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Stop Lamps Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | Press down the brake pedal. Do all of the stop lamps illuminate? | - | | Go to Step 3 |
| 3 | Are all lamps inoperative? | - | Go to Step 5 | Go to Step 4 |
| 4 | Test the voltage supply and ground circuits of the inoperative lamp or high mounted stop lamp for an open or high resistance. Did you find and correct the condition? | - | Go to Step 14 | Go to Step 9 |
| 5 | - Disconnect the brake switch.
- Probe the battery positive voltage circuit of the brake switch with a test lamp that is connected to a good ground.
Does the test lamp illuminate? | - | Go to Step 6 | Go to Step 10 |
| 6 | Connect a 10-amp fused jumper wire between the battery positive voltage circuit of the brake switch and the stop lamp supply voltage circuit. Do the stop lamps illuminate? | - | Go to Step 7 | Go to Step 11 |
| 7 | Inspect for poor connections at the harness connector of the brake switch. Did you find and correct the condition? | - | Go to Step 14 | Go to Step 8 |
| 8 | Inspect the brake switch for proper adjustment. Did you find and correct the condition? | - | Go to Step 14 | Go to Step 12 |
| 9 | Inspect for poor connections at the harness connector of the inoperative lamp or high mounted stop lamps. Did you find and correct the condition? | - | Go to Step 14 | Go to Step 13 |
| 10 | Repair an open, high resistance, or short to ground in the battery positive voltage circuit of the brake switch. Did you complete the repair? | - | Go to Step 14 | - |
| 11 | Repair an open or high resistance in the stop lamp supply voltage circuit. Did you complete the repair? | - | Go to Step 14 | - |
| 12 | Replace the brake switch. Did you complete the replacement? | - | Go to Step 14 | - |
| 13 | Replace the bulb or high mounted stop lamp assembly. Did you complete the replacement? | - | Go to Step 14 | - |
| 14 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Turn Signal Lamps and/or Indicators Inoperative
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Turn ON the ignition, with the engine OFF.
- Place the turn signal lever in the LEFT turn position.
- Place the turn signal lever in the RIGHT turn position.
Do the appropriate turn signal lamps and/or indicators illuminate for each action? | - | | Go to Step 3 |
| 3 | Is only one turn signal lamp inoperative? | - | Go to Step 6 | Go to Step 4 |
| 4 | Is only one of the turn signal indicators inoperative? | - | Go to Step 5 | Go to Step 7 |
| 5 | - Turn OFF the ignition.
- Disconnect the instrument panel cluster (IPC).
- Turn ON the ignition, with the engine OFF.
- Probe the inoperative turn signal supply voltage circuit of the IPC with a test lamp that is connected to a good ground.
- Place the turn signal lever in the position of the inoperative indicator.
Does the test lamp illuminate and flash. | - | Go to Step 10 | Go to Step 13 |
| 6 | - Disconnect the inoperative turn signal lamp.
- Probe the turn signal supply voltage circuit of the inoperative lamp with a test lamp that is connected to a good ground.
- Place the turn signal lever in the position of the inoperative lamp.
Does the test lamp illuminate and flash? | - | Go to Step 14 | Go to Step 15 |
| 7 | Do the hazard lamps operate properly? | - | Go to Step 8 | Go to Step 6 |
| 8 | - Disconnect the turn/hazard-headlamp switch.
- Probe the turn signal flasher signal circuit with a test lamp that is connected to a good ground.
Does the test lamp illuminate and flash? | - | Go to Step 11 | Go to Step 9 |
| 9 | Test the turn signal ?asher signal circuit for an open, high resistance, or short to ground. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 12 |
| 10 | Inspect for poor connections at the harness connector of the IPC. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 16 |
| 11 | Inspect for poor connections at the harness connector of the turn/hazard-headlamp switch. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 17 |
| 12 | Inspect for poor connections at the harness connector of the turn/hazard-?asher. Did you find and correct the condition? | - | Go to Step 19 | Go to Step 18 |
| 13 | Repair an open, high resistance, or short to ground in the inoperative turn signal supply voltage circuit. Did you complete the repair? | - | Go to Step 19 | - |
| 14 | Repair an open or high resistance in the ground circuit of the inoperative lamp. Did you complete the repair? | - | Go to Step 19 | - |
| 15 | Repair an open, high resistance, or short to ground in the inoperative turn signal supply voltage circuit. Did you complete the repair? | - | Go to Step 19 | - |
| 16 | Did you complete the replacement? | - | Go to Step 19 | - |
| 17 | Replace the turn/hazard-headlamp switch. Did you complete the replacement? | - | Go to Step 19 | - |
| 18 | Replace the turn/hazard-flasher. Did you complete the replacement? | - | Go to Step 19 | - |
| 19 | Operate the system in order to verify the repair. Did you correct the condition? | - | System OK | Go to Step 3 |
Diagnostic Trouble Code (DTC) B1000
ECU Malfunction
DTC Descriptors
DTC B1000 35: Electronic Control Unit (ECU) Performance ROM Integrity
DTC B1000 36: Electronic Control Unit (ECU) Performance EEPROM Integrity
Circuit/System Description
The internal fault detection is handled inside the control module. No external circuits are involved.
Conditions for Running the DTC
The module runs the program to detect an internal fault when power up is commanded. The only requirements are voltage and ground. This program runs even if the voltage is out of the valid operating range.
Conditions for Setting the DTC
The module has detected an internal malfunction.
Action Taken When the DTC Sets
The module refuses all additional inputs.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Electrical Information Reference
- This DTC may be stored as a history DTC without affecting the operation of the module.
- If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
- If this DTC is retrieved as both a current and history DTC, replace the module that set the DTC.
Circuit/System Verification
If this DTC is retrieved as a current DTC, replace the module that set the DTC.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Diagnostic Trouble Code (DTC) B1325
Device Power Circuit Malfunction
DTC Descriptors
DTC B1325 03: Voltage Below Threshold
DTC B1325 07: Voltage Above Threshold
Circuit/System Description
The control modules on this vehicle monitor the battery voltage through the battery positive voltage circuits. This vehicle has multiple modules that will set this DTC.
Conditions for Running the DTC
The voltage supplied to the control modules are in the range of 7-26 volts.
Conditions for Setting the DTC
DTC B1325 03
- The control module detects a system voltage below the calibrated value usually 9 volts.
- The above condition is present at least 5 seconds.
DTC B1325 07
- The control module detects a system voltage above the calibrated value usually 18 volts.
- The above condition is present at least 5 seconds.
Action Taken When the DTC Sets
- The control module immediately disables all outputs when an out of range voltage condition has been detected, with the exception of GMLAN and Run/Crank relay that are disabled after a 3 minute delay.
- The setting of other DTCs is inhibited.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
| Step | Action | Value(s) | Yes | No |
| 1 | Did you perform the Diagnostic System Check - Vehicle? | - | Go to Step 2 | Check the vehicle with the scan tool. |
| 2 | - Install a scan tool.
- Turn ON the ignition, with the engine OFF.
- With a scan tool, observe the Battery Voltage Signal parameter in the data list of the module setting the DTC.
Is the Battery Voltage Signal parameter displayed in the specified range? | 9 - 18 V | Go to Step 3 | Go to Step 4 |
| 3 | Is the DTC set as a current DTC? | - | Go to Step 7 | |
| 4 | - Disconnect the harness connector of the module setting the DTC.
- Measure the voltage between the battery positive voltage circuit at the module harness connector and a good ground.
Is the measured value in the specified range? | 9 - 18 V | Go to Step 6 | Go to Step 5 |
| 5 | Test the battery positive voltage circuit for the following conditions: - A short to ground
- An open
- A high resistance
Did you find and correct the condition? | - | Go to Step 9 | |
| 6 | Test the all of ground circuits of the module for an open or high resistance. Did you find and correct the condition? | - | Go to Step 9 | Go to Step 7 |
| 7 | Did you find and correct the condition? | - | Go to Step 9 | Go to Step 8 |
| 8 | Did you complete the replacement? | - | Go to Step 9 | - |
| 9 | Operate the system in order to verify the repair. Did you find and correct the condition? | - | System OK | Go to Step 2 |
Diagnostic Trouble Code (DTC) B3078
Security System Horn Output Circuit
DTC Descriptors
DTC B3078 01: Security System Output Circuit - Short to Ground
DTC B3078 06: Security System Output Circuit - Short to Battery or Open
Circuit/System Description
The auxiliary body control module (XBCM) controls the horn relay by grounding the control circuit of the horn relay coil energizing the relay.
Conditions for Running the DTC
The ignition is ON.
Left turn signal lamps must be ON and the left turn signal lamp must be commanded ON.
Conditions for Setting the DTC
The XBCM detects an open, short to ground, or short to voltage on the security system horn circuit while trying to apply a voltage to the circuit.
Action Taken When the DTC Sets
The security system horns not activate.
Conditions for Clearing the DTC
- The conditions for setting the DTC are no longer present.
- A history DTC clears after 100 malfunction-free ignition cycles.
- The BCM receives the clear code command from the scan tool.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Verification
Ignition ON, activate with a scan tool the Trailer Left Turn Signal Lamp output control for the auxiliary body control module (XBCM). The Turn Signal Lamp Relay Cmd. Data parameter should display ON and the trailer left turn signal lamp should illuminate.
Circuit/System Testing
- Test the horn relay control circuit for an open or short to battery.
- Inspect for poor connections at the harness connector of the XBCM.
- If all circuits/connections test normal, replace the XBCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Diagnostic Trouble Code (DTC) B3887
Trailer Left Turn Signal Circuit
DTC Descriptors
DTC B3887 02: Trailer Left Turn Signal Circuit - Short to Ground
DTC B3887 05: Trailer Left Turn Signal Circuit - Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
When the left turn signal switch is placed in the ON position, ground is applied to the auxiliary body control module (XBCM) through the turn signal lamp switch circuit. The XBCM then applies voltage on the trailer turn signal lamp circuit to the trailer left turn signal lamp.
Conditions for Running the DTC
The ignition is ON.
Left turn signal lamps must be ON and the left turn signal lamp must be commanded ON.
Conditions for Setting the DTC
The BCM detects an open, short to ground, or short to voltage on the trailer left turn signal lamp circuit while trying to apply a voltage to the circuit.
Action Taken When the DTC Sets
The trailer left turn signal lamp do not illuminate.
Conditions for Clearing the DTC
- The conditions for setting the DTC are no longer present.
- A history DTC clears after 100 malfunction-free ignition cycles.
- The BCM receives the clear code command from the scan tool.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Verification
Ignition ON, activate the Trailer Left Turn Signal Lamp switch, trailer left turn signal lamp should illuminate.
Circuit/System Testing
- Inspect the trailer left turn signal lamp bulb for an open or shorted filament.
- If the bulb is inoperable, replace the bulb.
- Turn signal lamp switch OFF, Clear the DTC, test the trailer left turn signal lamp circuit for a short to voltage, short to ground, an open, or high resistance.
- If all circuits/connections test normal, replace the XBCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for XBCM replacement, setup, and programming.
Diagnostic Trouble Code (DTC) B3888
Trailer Right Turn Signal Circuit
DTC Descriptors
DTC B3888 02: Trailer Right Turn Signal Circuit - Short to Ground
DTC B3888 05: Trailer Right Turn Signal Circuit - Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
When the right turn signal switch is placed in the ON position, ground is applied to the auxiliary body control module (XBCM) through the turn signal lamp switch circuit. The XBCM then applies voltage on the trailer turn signal lamp circuit to the trailer right turn signal lamp.
Conditions for Running the DTC
The ignition is ON.
Right turn signal lamps must be ON and the right turn signal lamp must be commanded ON.
Conditions for Setting the DTC
The BCM detects an open, short to ground, or short to voltage on the trailer right turn signal lamp circuit while trying to apply a voltage to the circuit.
Action Taken When the DTC Sets
The trailer right turn signal lamp do not illuminate.
Conditions for Clearing the DTC
- The conditions for setting the DTC are no longer present.
- A history DTC clears after 100 malfunction-free ignition cycles.
- The BCM receives the clear code command from the scan tool.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Verification
Ignition ON, activate the Trailer Right Turn Signal Lamp switch, trailer right turn signal lamp should illuminate.
Circuit/System Testing
- Inspect the trailer right turn signal lamp bulb for an open or shorted filament.
- If the bulb is inoperable, replace the bulb.
- Turn signal lamp switch OFF, Clear the DTC, test the trailer left turn signal lamp circuit for a short to voltage, short to ground, an open, or high resistance.
- If all circuits/connections test normal, replace the XBCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for XBCM replacement, setup, and programming
Diagnostic Trouble Code (DTC) B3891
Trailer Foglamps Circuit
DTC Descriptors
DTC B3891 02: Trailer Fog Lamps Circuit Short to Ground
DTC B3891 05: Trailer Fog Lamps Circuit Short to Battery or Open
Diagnostic Fault Information
Circuit/System Description
When the rear fog lamp switch is placed in the ON position, ground is applied to the auxiliary body control module (XBCM) through the rear fog lamp switch circuit. The XBCM then applies voltage on the trailer fog lamp circuit to the trailer rear fog lamp.
Conditions for Running the DTC
The ignition is ON.
Park lamps must be ON and the rear fog lamps must be commanded ON.
Conditions for Setting the DTC
The BCM detects an open, short to ground, or short to voltage on the trailer rear fog lamp circuit while trying to apply a voltage to the circuit.
Action Taken When the DTC Sets
The trailer rear fog lamps do not illuminate.
Conditions for Clearing the DTC
- The conditions for setting the DTC are no longer present.
- A history DTC clears after 100 malfunction-free ignition cycles.
- The BCM receives the clear code command from the scan tool.
Electrical Information Reference
- Circuit Testing
- Connector Repairs
- Testing for Intermittent Conditions and Poor Connections
- Wiring Repairs
Circuit/System Verification
Ignition ON, activate with a scan tool the Trailer Fog Lamps output control for the auxiliary body control module (XBCM). The Rear Fog Lamp Relay Cmd. Data parameter should display ON and the trailer rear fog lamps should illuminate.
Circuit/System Testing
- Inspect the trailer rear fog lamp bulb for an open or shorted filament.
- If the bulb is inoperable, replace the bulb.
- Park lamp switch OFF, Clear the DTC, test the trailer rear fog lamp circuit for a short to voltage, short to ground, an open, or high resistance.
- If all circuits/connections test normal, replace the XBCM.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for XBCM replacement, setup, and programming.
Diagnostic Trouble Code (DTC) B0140
Lost Communication With Body Control Module (BCM)
Circuit Description
Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START.
Conditions for Running the DTC
The system voltage is between 9-16 volts.
The vehicle power mode master requires serial data communication to occur.
Conditions for Setting the DTC
A supervised periodic message that includes the transmitter module availability has not been received.
Action Taken When the DTC Sets
The module(s) is never signaled, therefore the specific subsystem(s) will not function.
Conditions for Clearing the DTC
A current DTC clears when the malfunction is no longer present.
A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Diagnostic Aids
Park lamp switch OFF, Clear the DTC, test the trailer rear fog lamp circuit for a short to voltage, short to ground, an open, or high resistance.
If there are multiple non-communicating modules choose the one closest to the data link connector (DLC).
Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to ground before replacing the module.
This diagnostic can be used for any module that should communicate with high or low speed GMLAN serial data providing the vehicle is equipped with the option that uses that module.
Repair Instructions
Diagnostic Trouble Code (DTC) U0155
Lost Communication With Instrument Panel Cluster (IPC) Control Module
Circuit Description
Modules connected to the high and low speed GMLAN serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. Each message contains the identification number of the transmitter module.
The body control module (BCM) activates the serial data communication enable and the accessory wakeup serial data circuits by applying voltage when the ignition key is in ACC, ON or START. The serial data communication enable circuit wakes up the electronic brake control module (EBCM) for bus communication and the accessory wakeup serial data circuit wakes up the engine control module (ECM) and transmission control module (TCM).
Conditions for Running the DTC
- The system voltage is between 9-16 volt
- The vehicle power mode master requires serial data communication to occur.
Conditions for Setting the DTC
A supervised periodic message that includes the transmitter module availability has not been received.
Action Taken When the DTC Sets
The module(s) is never signaled, therefore the specific subsystem(s) will not function.
Conditions for Clearing the DTC
- A current DTC clears when the malfunction is no longer present.
- A history DTC clears when the module ignition cycle counter reaches the reset threshold of 50, without a repeat of the malfunction.
Diagnostic Aids
If there are multiple non-communicating modules choose the one closest to the data link connector (DLC).
Some modules may not have internal protection for specific voltage outputs and may open a battery positive voltage or ignition voltage source fuse. If a voltage input fuse is open and no short is found in that circuit, ensure that no module output voltage circuit is shorted to ground before replacing the module.
This diagnostic can be used for any module that should communicate with high or low speed CAN serial data providing the vehicle is equipped with the option that uses that module.
This diagnostic can be used for any module that should communicate with high or low speed GMLAN serial data providing the vehicle is equipped with the option that uses that module.
Circuit/System Testing
Using the Diagnostic Aids above, determine the module that is not communicating that should be tested.
Ignition OFF, disconnect the harness connector of the module that is not communicating.
Important : Only the high speed CAN modules have a the serial data communication enable circuit OR the accessory wakeup serial data circuit. If the module that is not communicating does not have one of these circuits, proceed to step 4.
Ignition ON, verify that a test lamp illuminates between the serial data communication enable circuit OR the accessory wakeup serial data circuit and ground.
If the test lamp does not illuminate, repair the circuit for an open/high resistance. If the circuits test normal, replace the BCM.
Ignition ON, verify that a test lamp illuminates between all battery positive voltage circuits and ground.
If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
Verify that a test lamp illuminates between all ignition voltage circuits and ground.
If the test lamp does not illuminate, repair the circuit for a short to ground or an open/high resistance. If the circuit fuse is open, also test the positive voltage outputs of the module for a short to ground. If the circuits test normal, replace the faulty module.
Test for less than 1 ohm of resistance between the module ground circuits and ground.
If greater than 1 ohm, repair the ground circuit for an open.
Determine if the non-communicating module should use low speed CAN serial data.
If the module is GMLAN high speed only, replace the module.
Test for less than 1 ohm of resistance in the low speed CAN serial data circuit between the non-communicating module and the module that displays the DTC.
If greater than 1 ohm of resistance, test the low speed CAN serial data circuit for open/high resistance.
If all circuits test normal, replace the module that is not communicating.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Refer to
Section 9A, Body Wiring Systems. The related module and the non-communicating module replacement, setup and programming.
