LAMPS/LIGHTING - EXTERIOR

WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental restraint system before attempting any steering wheel, steering column, airbag, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge before performing further diagnosis or service. This is the only sure way to disable the supplemental restraint system. Failure to take the proper precautions could result in accidental airbag deployment.

NOTE: When diagnosing the exterior lighting circuits, remember that high generator output can burn out bulbs rapidly and repeatedly; and, that dim or flickering bulbs can be caused by low generator output or poor battery condition. If one of these symptoms is a problem on the vehicle, be certain to diagnose the battery and charging system, then repair as necessary.

NOTE: A good ground is necessary for proper lighting operation. If a lighting problem is being diagnosed that involves multiple symptoms, systems, or components, the problem can often be traced to a loose, corroded, or open ground.

The lamps and the hard wired circuits between components related to the exterior lighting system may be diagnosed using conventional diagnostic tools and procedures. Refer to the appropriate wiring information. The wiring information includes wiring diagrams, proper wire and connector repair procedures, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds.

However, conventional diagnostic methods will not prove conclusive in the diagnosis of the exterior lighting system or the electronic controls or communication between modules and other devices that provide some features of the exterior lighting system. The most reliable, efficient, and accurate means to diagnose the exterior lighting system or the electronic controls and communication related to exterior lighting system operation requires the use of a diagnostic scan tool. Refer to the appropriate diagnostic information.


BACKUP LAMPS


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
BACKUP LAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing fuse.
 
1. Test and replace backup lamp fuse if required.
 
2. Ineffective or missing bulb.
 
2. Test and replace backup lamp bulb if required.
 
 
3. Ineffective ground circuit.
 
3. Test and repair open backup lamp ground circuit if required.
 
 
4. Ineffective feed circuit.
 
4. Test and repair open backup lamp feed circuit if required.
 
 
5. Ineffective switch.
 
5. Test and replace transmission range sensor if required.
 
 
6. Ineffective FCM inputs or outputs.
 
6. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
BACKUP LAMP DOES NOT EXTINGUISH
 
1. Ineffective feed circuit.
 
1. Test and repair shorted backup lamp feed circuit if required.
 
2. Ineffective switch.
 
2. Test and replace transmission range sensor if required.
 
 
3. Ineffective FCM inputs or outputs.
 
3. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 


BRAKE LAMPS

NOTE: The Center High Mounted Stop Lamp (CHMSL) is illuminated by several Light-Emitting Diode (LED) units that are soldered to the electronic circuit board within the lamp housing. If the brake lamps and all of the LED units within the CHMSL fail to operate, diagnose and repair the brake lamps before attempting to repair the CHMSL. If the brake lamps operate but none of the CHMSL LED units illuminate, test and repair the CHMSL ground or feed circuit if required. If some of the CHMSL LED units operate and some do not, the CHMSL assembly must be replaced with a new unit.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
BRAKE LAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing fuse.
 
1. Test and replace brake lamp fuse if required.
 
2. Ineffective or missing bulb.
 
2. Test and replace brake lamp bulb if required.
 
 
3. Ineffective ground circuit.
 
3. Test and repair open brake lamp ground circuit if required.
 
 
4. Ineffective feed circuit.
 
4. Test and repair open brake lamp switch output circuit if required.
 
 
5. Ineffective switch.
 
5. Test and replace brake lamp switch if required.
 
 
6. Ineffective stop lamp inhibit relay (with Electronic Stability Program (ESP) or Traction Control System (TCS) only).
 
6. Test and replace stop lamp inhibit relay if required.
 
 
BRAKE LAMP DOES NOT EXTINGUISH
 
1. Ineffective supply circuit.
 
1. Test and repair shorted brake lamp switch output circuit if required.
 
2. Ineffective switch.
 
2. Test and replace brake lamp switch if required.
 
 


DAYTIME RUNNING LAMPS

NOTE: Before performing the following tests, determine whether the headlamp low and high beams operate. If the headlamp low and high beams are also ineffective, diagnose and repair that problem before attempting to repair the Daytime Running Lamps.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
DAYTIME RUNNING LAMPS WILL NOT ILLUMINATE
 
1. Incorrect FCM programming.
 
1. Use a diagnostic scan tool to check and correct the FCM programming if required. Refer to the appropriate diagnostic information.
 
2. Automatic transmission in PARK position.
 
2. Place the transmission gear selector lever in any position except PARK.
 
 
3. Parking brake applied.
 
3. Release the parking brake.
 
 
4. Engine not running.
 
4. Start the engine.
 
 
5. Ineffective FCM inputs or outputs.
 
5. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 


FRONT FOG LAMPS

NOTE: In addition to the front fog lamp units, the vehicle must have the appropriate left multi-function switch installed. Also, both the Front Control Module (FCM) and the Steering Control Module (SCM) must be properly configured for the front fog lamps option using a diagnostic scan tool. Refer to the appropriate diagnostic information.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
FRONT FOG LAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing fuse.
 
1. Test and replace front fog lamp fuse if required.
 
2. Ineffective or missing bulb.
 
2. Test and replace front fog lamp bulb if required.
 
 
3. Ineffective ground circuit.
 
3. Test and repair open front fog lamp ground circuit if required.
 
 
4. Ineffective feed circuit.
 
4. Test and repair open front fog lamp relay output circuit if required.
 
 
5. Ineffective or missing relay.
 
5. Test and replace front fog lamp relay if required.
 
 
6. Ineffective switch.
 
6. Test and replace left multi-function switch if required.
 
 
7. Incorrect FCM or SCM configuration.
 
7. Use a diagnostic scan tool to check and correct the FCM and SCM configuration settings if required. Refer to the appropriate diagnostic information.
 
 
8. Ineffective SCM inputs or outputs.
 
8. Use a diagnostic scan tool to test the SCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
9. Ineffective FCM inputs or outputs.
 
9. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
FRONT FOG LAMP DOES NOT EXTINGUISH
 
1. Ineffective feed circuit.
 
1. Test and repair shorted front fog lamp relay output circuit if required.
 
2. Ineffective relay.
 
2. Test and replace front fog lamp relay if required.
 
 
3. Ineffective switch.
 
3. Test and replace left multi-function switch if required.
 
 
4. Ineffective SCM inputs or outputs.
 
4. Use a diagnostic scan tool to test the SCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
5. Ineffective FCM inputs or outputs.
 
5. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 


HAZARD WARNING LAMPS

NOTE: Before performing the following tests, confirm whether the left and right turn signals operate satisfactorily. If the turn signals are ineffective or operate improperly, diagnose and repair that problem before attempting to repair the Hazard Warning Lamps.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
HAZARD WARNING LAMPS DO NOT FLASH
 
1. Ineffective switch.
 
1. Test and replace multi-function switch if required.
 
2. Ineffective FCM inputs or outputs.
 
2. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
HAZARD WARNING LAMPS DO NOT STOP FLASHING
 
1. Ineffective switch.
 
1. Test and replace multi-function switch if required.
 
2. Ineffective FCM inputs or outputs.
 
2. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 


HEADLAMPS

NOTE: As part of the exterior lighting failsafe feature, upon ignition ON the park lamps and the headlamp low beams will illuminate regardless of the left multi-function switch control knob position if the Steering Control Module (SCM) cannot detect an input from the left multi-function switch, or if there is a loss of data bus communication. In addition, for automatic headlamps, the vehicle must have the appropriate left multi-function switch installed and the Auto Low or the Auto Low/High option must be enabled using the customer programmable features function of the Electronic Vehicle Information Center (EVIC). Also, both the Front Control Module (FCM) and the Steering Control Module (SCM) must be properly configured for the automatic headlamps option using a diagnostic scan tool. Refer to the appropriate diagnostic information.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
HEADLAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing bulb.
 
1. Test and replace headlamp bulb if required.
 
2. Ineffective ground circuit.
 
2. Test and repair open headlamp ground circuit if required.
 
 
3. Ineffective feed circuit.
 
3. Test and repair open headlamp low beam or high beam feed circuit if required.
 
 
HEADLAMP DOES NOT EXTINGUISH
 
1. Ineffective feed circuit.
 
1. Test and repair shorted headlamp low beam or high beam feed circuit if required.
 
2. Ineffective switch.
 
2. Test and replace left multi-function switch if required.
 
 
HEADLAMPS ILLUMINATE WITH IGNITION ON AND HEADLAMP SWITCH OFF (FAIL-SAFE OPERATION)
 
1. Ineffective circuits between headlamp switch and SCM.
 
1. Test and repair left multi-function switch mux and return circuits if required.
 
2. Loss of data bus communication.
 
2. Use a diagnostic scan tool to test the data bus. Refer to the appropriate diagnostic information.
 
 
3. Ineffective switch.
 
3. Test and replace left multi-function switch if required.
 
 
HEADLAMPS WILL NOT SWITCH FROM HIGH TO LOW BEAMS, OR FROM LOW TO HIGH BEAMS
 
1. Ineffective circuits between multi-function switch and SCM.
 
1. Test and repair wash/beam select mux and multi-function switch return circuits if required.
 
2. Ineffective switch.
 
2. Test and replace left multi-function switch if required.
 
 
AUTO HEADLAMPS INEFFECTIVE
 
1. Feature not enabled.
 
1. Enable Auto Low or Auto Low/High using the customer programmable features function of the Electronic Vehicle Information Center (EVIC).
 
2. Incorrect or ineffective switch.
 
2. Inspect, test and replace left multi-function switch if required.
 
 
3. Incorrect FCM or SCM configuration.
 
3. Use a diagnostic scan tool to check and correct the FCM or SCM configuration settings if required. Refer to the appropriate diagnostic information.
 
 
4. Ineffective circuits between sun load sensor and instrument cluster (except with SmartBeam®).
 
4. Test and repair sun sensor and sun sensor return circuits if required (except with SmartBeam®).
 
 
5. Ineffective sun load sensor (except with SmartBeam®).
 
5. Test and replace sun load sensor if required (except with SmartBeam®).
 
 
6. Ineffective Rain/Light Sensor Module (RSM) (with SmartBeam®).
 
6. Use a diagnostic scan tool to test and replace the RSM if required. Refer to the appropriate diagnostic information (with SmartBeam®).
 
 


HEADLAMP LEVELING

NOTE: Before performing the following tests, confirm whether the park lamps operate properly. If the park lamps are ineffective, diagnose and repair that problem before attempting to repair the Headlamp Leveling System.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
ONE LEVELING MOTOR IS INEFFECTIVE
 
1. Ineffective ground circuit.
 
1. Test and repair open leveling motor ground circuit if required.
 
2. Ineffective feed circuit.
 
2. Test and repair open leveling motor feed circuit if required.
 
 
3. Ineffective signal circuit.
 
3. Test and repair open headlamp adjust signal circuit if required.
 
 
4. Ineffective motor.
 
4. Test and replace headlamp leveling motor (front lamp unit) if required.
 
 
BOTH LEVELING MOTORS ARE INEFFECTIVE
 
1. Ineffective switch ground circuit.
 
1. Test and repair open leveling switch ground circuit if required.
 
2. Ineffective motor ground circuit.
 
2. Test and repair open leveling motor ground circuit if required.
 
 
3. Ineffective switch feed circuit.
 
3. Test and repair open leveling switch feed circuit if required.
 
 
4. Ineffective motor feed circuit.
 
4. Test and repair open leveling motor feed circuit if required.
 
 
5. Ineffective signal circuit.
 
5. Test and repair open or shorted leveling motor signal circuit if required.
 
 
6. Ineffective switch.
 
6. Test and replace leveling switch (instrument panel upper switch pod) if required.
 
 
7. Ineffective motors.
 
7. Test and replace leveling motors (front lamp units) if required.
 
 


PARK LAMPS

NOTE: As part of the exterior lighting failsafe feature, upon ignition ON the exterior park lamps and the headlamp low beams will illuminate regardless of the left multi-function switch control knob position if the Steering Control Module (SCM) cannot detect an input from the left multi-function switch, or if there is a loss of data bus communication.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
PARK LAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing fuse.
 
1. Test and replace park lamp fuse if required.
 
2. Ineffective or missing bulb.
 
2. Test and replace park lamp bulb if required.
 
 
3. Ineffective or missing relay.
 
3. Test and replace park lamp relay if required.
 
 
4. Ineffective ground circuit.
 
4. Test and repair open park lamp ground circuit if required.
 
 
5. Ineffective feed circuit.
 
5. Test and repair open park lamp relay output circuit if required.
 
 
6. Ineffective SCM inputs or outputs.
 
6. Use a diagnostic scan tool to test the SCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
7. Ineffective FCM inputs or outputs.
 
7. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
PARK LAMP DOES NOT EXTINGUISH
 
1. Ineffective feed circuit.
 
1. Test and repair shorted park lamp relay output circuit if required.
 
2. Ineffective relay.
 
2. Test and replace park lamp relay if required.
 
 
3. Ineffective switch.
 
3. Test and replace left multi-function switch if required.
 
 
4. Ineffective SCM inputs or outputs.
 
4. Use a diagnostic scan tool to test the SCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 
5. Ineffective FCM inputs or outputs.
 
5. Use a diagnostic scan tool to test the FCM inputs and outputs. Refer to the appropriate diagnostic information.
 
 


REAR FOG LAMPS

NOTE: In addition to the rear fog lamp units, the vehicle must have the appropriate left multi-function switch or upper instrument panel switch pod installed. Also, both the Front Control Module (FCM) and the Steering Control Module (SCM) must be properly configured for the rear fog lamps option using a diagnostic scan tool. Refer to the appropriate diagnostic information.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
REAR FOG LAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing fuse.
 
1. Test and replace rear fog lamp fuse if required.
 
2. Ineffective or missing bulb.
 
2. Test and replace rear fog lamp bulb if required.
 
 
3. Ineffective ground circuit.
 
3. Test and repair open rear fog lamp ground circuit if required.
 
 
4. Ineffective feed circuit.
 
4. Test and repair open rear fog lamp relay output circuit if required.
 
 
5. Ineffective or missing relay.
 
5. Test and replace rear fog lamp relay if required.
 
 
6. Incorrect or ineffective switch.
 
6. Inspect, test and replace left multi-function switch or upper instrument panel switch pod if required.
 
 
7. Incorrect FCM or SCM configuration.
 
7. Use a diagnostic scan tool to check and correct the FCM or SCM configuration settings if required. Refer to the appropriate diagnostic information.
 
 
REAR FOG LAMP DOES NOT EXTINGUISH
 
1. Ineffective feed circuit.
 
1. Test and repair shorted rear fog lamp relay output circuit if required.
 
2. Ineffective relay.
 
2. Test and replace rear fog lamp relay if required.
 
 
3. Ineffective switch.
 
3. Test and replace left multi-function switch or upper instrument panel switch pod if required.
 
 


SMARTBEAM®

NOTE: For SmartBeam® to operate, the vehicle must have the appropriate left multi-function switch installed and the Auto Low/High option must be enabled using the customer programmable features function of the Electronic Vehicle Information Center (EVIC). Also, both the Front Control Module (FCM) and the Steering Control Module (SCM) must be properly configured for the automatic headlamps option using a diagnostic scan tool. Refer to the appropriate diagnostic information.


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
SMARTBEAM® INEFFECTIVE AND GREEN LED ON INSIDE REAR VIEW MIRROR NOT FLASHING
 
1. Feature not enabled.
 
1. Enable Auto Low/High using the customer programmable features function of the Electronic Vehicle Information Center (EVIC).
 
2. Automatic headlamps are not turned ON.
 
2. Turn automatic headlamps ON using the control knob on the left multi-function switch control stalk.
 
 
3. Vehicle speed is below 32 kilometers-per-hour (20 miles-per-hour).
 
3. Increase vehicle speed. SmartBeam® is not designed to operate at speeds below 32 kilometers-per-hour (20 miles-per-hour).
 
 
4. Incorrect or ineffective switch.
 
4. Inspect, test and replace left multi-function switch if required.
 
 
5. Incorrect FCM or SCM configuration.
 
5. Use a diagnostic scan tool to check and correct the FCM or SCM configuration settings if required. Refer to the appropriate diagnostic information.
 
 
6. SmartBeam® imager lens dirty or obstructed.
 
6. Initiate the Imager Optics Test from the Demonstration Mode to confirm the function of the SmartBeam® optics. Clean imager lens and windshield or remove obstructions from the windshield glass if required.
 
 
7. Ineffective ground circuit.
 
7. Test and repair open ground circuit to inside rear view mirror as required.
 
 
8. Ineffective feed circuit.
 
8. Test and repair open fused run relay output circuit to inside rear view mirror if required.
 
 
9. Loss of data bus communication.
 
9. Use a diagnostic scan tool to test the data bus. Refer to the appropriate diagnostic information.
 
 
10. Ineffective inside rear view mirror.
 
10. Use a diagnostic scan tool to test the ElectroChromic (EC) inside rear view mirror. Refer to the appropriate diagnostic information.
 
 
SMARTBEAM® INEFFECTIVE AND GREEN LED ON INSIDE REAR VIEW MIRROR FLASHING CONTINUALLY
 
1. SmartBeam® calibration required (slow flash - once-per-second).
 
1. Perform the SmartBeam® Calibration procedure.
 
2. SmartBeam® failed calibration procedure due to improper set up (fast flash - twice-per-second).
 
2. Perform the SmartBeam® Calibration procedure properly.
 
 
3. SmartBeam® failed calibration procedure due to a mechanical misalignment (fast flash - twice-per-second).
 
3. Use a diagnostic scan tool to retrieve the Diagnostic Trouble Code (DTC). Refer to the appropriate diagnostic information. Perform the appropriate SmartBeam® Imager Shim Adjustment procedure.
 
 
SMARTBEAM® INEFFECTIVE AND GREEN LED ON INSIDE REAR VIEW MIRROR FLASHES ONLY AFTER IGNITION IS CYCLED ON
 
1. Three or four flashes after cycling ignition ON.
 
1. Internal mirror fault - ElectroChromic (EC) system failure. Replace the EC mirror if required.
 
2. Five flashes after cycling ignition ON.
 
2. Internal mirror fault - active light sensor system failure. Replace the EC mirror if required.
 
 
3. Six flashes after cycling ignition ON.
 
3. Internal mirror fault - SmartBeam® camera (imager) failure. Replace the EC mirror if required.
 
 


TURN SIGNAL LAMPS


CONDITION
 
POSSIBLE CAUSES
 
CORRECTION
 
ONE TURN SIGNAL LAMP DOES NOT ILLUMINATE
 
1. Ineffective or missing bulb.
 
1. Test and replace turn signal bulb if required.
 
2. Ineffective ground circuit.
 
2. Test and repair open ground circuit if required.
 
 
3. Ineffective feed circuit.
 
3. Test and repair open right or left turn signal circuit if required.
 
 
ALL RIGHT SIDE OR ALL LEFT SIDE TURN SIGNAL LAMPS DO NOT FLASH
 
1. Ineffective switch.
 
1. Test and replace left multi-function switch if required.
 
2. Ineffective feed circuit.
 
2. Test and repair open right or left turn signal circuit if required.
 
 
ALL RIGHT SIDE OR ALL LEFT SIDE TURN SIGNALS FLASH TOO RAPIDLY (MORE THAN 100 FLASHES PER MINUTE)
 
1. Ineffective or missing bulb.
 
1. Test and replace turn signal bulb if required.
 
2. Ineffective ground circuit.
 
2. Test and repair open ground circuit if required.
 
 
3. Ineffective feed circuit.
 
3. Test and repair open right or left turn signal circuit if required.