To avoid serious or fatal injury on vehicles equipped with airbags, disable the supplemental restraint system before attempting any steering wheel, steering column, airbag, occupant classification system, 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.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.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.CONDITIONPOSSIBLE CAUSESCORRECTIONBACKUP LAMP DOES NOT ILLUMINATE1. Ineffective or missing bulb.1. Test and replace backup lamp bulb if required.2. Ineffective ground circuit.2. Test and repair open backup lamp ground circuit if required.3. Ineffective feed circuit.3. Test and repair open backup lamp feed circuit if required.4. Ineffective switch.4. Test and replace backup lamp switch (manual transmission) or transmission range sensor (automatic transmission) if required.5. Ineffective TIPM inputs or outputs.5. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.BACKUP LAMP DOES NOT EXTINGUISH1. Ineffective feed circuit.1. Test and repair shorted backup lamp feed circuit if required.2. Ineffective switch.2. Test and replace backup lamp switch (manual transmission) or transmission range sensor (automatic transmission) if required.3. Ineffective TIPM inputs or outputs.3. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.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. The CHMSL is hard wired to the output of the brake lamp switch, while the brake lamps are powered by high side drivers within the TIPM based upon an input from the brake lamp switch. 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 others do not, the CHMSL assembly must be replaced with a new unit.CONDITIONPOSSIBLE CAUSESCORRECTIONBRAKE LAMP DOES NOT ILLUMINATE1. Ineffective or missing bulb.1. Test and replace brake lamp bulb if required.2. Ineffective ground circuit.2. Test and repair open brake lamp ground circuit if required.3. Ineffective fuse.3. Test and replace the fuse in the TIPM if required.4. Ineffective feed circuit.4. Test and repair open brake lamp switch output circuit or stop lamp output circuit if required.5. Ineffective switch.5. Test and replace brake lamp switch if required.6. Ineffective TIPM inputs or outputs.6. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.BRAKE LAMP DOES NOT EXTINGUISH1. Ineffective feed circuit.1. Test and repair shorted brake lamp switch output circuit or stop lamp output circuit if required.2. Improperly adjusted switch.2. Adjust the brake lamp switch if required.3. Ineffective switch.3. Test and replace brake lamp switch if required.4. Ineffective TIPM inputs or outputs.4. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.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.CONDITIONPOSSIBLE CAUSESCORRECTIONDAYTIME RUNNING LAMPS WILL NOT ILLUMINATE1. Incorrect TIPM programming.1. Use a diagnostic scan tool to check and configure TIPM if required.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 TIPM inputs or outputs.5. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.The front fog lamp switch is integral to the left multi-function switch/Steering Control Module (SCM), which communicates with the ElectroMechanical Instrument Cluster (EMIC)/Cab Compartment Node (CCN) over the Local Interface Network (LIN) data bus. Before performing any of the following tests, determine whether the other functions of the left multi-function switch/SCM are operational. If the other left multi-function switch/SCM functions are ineffective, diagnose and repair that problem before attempting to repair the Front Fog Lamps.CONDITIONPOSSIBLE CAUSESCORRECTIONFRONT FOG LAMP DOES NOT ILLUMINATE1. Ineffective or missing bulb.1. Test and replace front fog lamp bulb if required.2. Ineffective ground circuit.2. Test and repair open front fog lamp ground circuit if required.3. Ineffective feed circuit.3. Test and repair open front fog lamp feed circuit if required.4. Ineffective EMIC (CCN) inputs or outputs.4. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.5. Ineffective TIPM inputs or outputs.5. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.FRONT FOG LAMP DOES NOT EXTINGUISH1. Ineffective feed circuit.1. Test and repair shorted front fog lamp feed circuit if required.2. Ineffective EMIC (CCN) inputs or outputs.2. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.3. Ineffective TIPM inputs or outputs.3. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.The hazard switch is integral to the instrument panel switch bank, which communicates with the EMIC/CCN over the LIN data bus. Before performing any of the following tests, confirm whether the left and right turn signals operate satisfactorily. Then determine whether the other functions of the instrument panel switch bank are operational. If the turn signals are ineffective or operate improperly, or if the other instrument panel switch bank functions are ineffective, diagnose and repair those problems before attempting to repair the Hazard Warning Lamps.CONDITIONPOSSIBLE CAUSESCORRECTIONHAZARD WARNING LAMPS DO NOT FLASH1. Ineffective EMIC (CCN) inputs or outputs.1. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.2. Ineffective TIPM inputs or outputs.2. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.HAZARD WARNING LAMPS DO NOT STOP FLASHING1. Ineffective EMIC (CCN) inputs or outputs.1. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.2. Ineffective TIPM inputs or outputs.2. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.As part of the exterior lighting failsafe feature, upon ignition ON, all exterior park lamps and the headlamp low beams will illuminate regardless of the left multi-function switch control knob position if the SCM cannot detect an input from the left multi-function switch, or if there is a loss of communication between the left multi-function switch/SCM and the EMIC or between the EMIC and the TIPM. Diagnose and repair those problems before attempting to repair the Headlamps. In addition, the TIPM will store a Diagnostic Trouble Code (DTC) for an open or shorted headlamp circuit.CONDITIONPOSSIBLE CAUSESCORRECTIONHEADLAMP DOES NOT ILLUMINATE1. 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.4. Ineffective EMIC (CCN) inputs or outputs.4. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.5. Ineffective TIPM inputs or outputs.5. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.HEADLAMP DOES NOT EXTINGUISH1. Ineffective feed circuit.1. Test and repair shorted headlamp low beam or high beam feed circuit if required.2. Ineffective EMIC (CCN) inputs or outputs.2. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.3. Ineffective TIPM inputs or outputs.3. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.HEADLAMPS ILLUMINATE WITH IGNITION ON AND HEADLAMP SWITCH OFF (FAIL-SAFE OPERATION)1. Loss of LIN or CAN data bus communication.1. Test and repair the LIN or CAN data bus if required. Refer to the appropriate diagnostic information.HEADLAMPS WILL NOT SWITCH FROM HIGH TO LOW BEAMS, OR FROM LOW TO HIGH BEAMS1. Ineffective EMIC (CCN) inputs or outputs.1. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.2. Ineffective TIPM inputs or outputs.2. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.The headlamp leveling switch is integral to the instrument panel switch bank, which communicates with the EMIC/CCN over the LIN data bus. Before performing any of the following tests, confirm whether the park lamps operate satisfactorily. Then determine whether the other functions of the instrument panel switch bank are operational. If the park lamps are ineffective or operate improperly, or if the other instrument panel switch bank functions are ineffective, diagnose and repair those problems before attempting to repair the Headlamp Leveling function.CONDITIONPOSSIBLE CAUSESCORRECTIONONE LEVELING MOTOR IS INEFFECTIVE1. 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 leveling motor signal circuit if required.4. Ineffective motor.4. Test and replace headlamp leveling motor if required.BOTH LEVELING MOTORS ARE INEFFECTIVE1. Ineffective EMIC (CCN) inputs or outputs.1. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.2. Ineffective motor ground circuit.2. Test and repair open leveling motor ground circuit if required.3. Ineffective motor feed circuit.3. Test and repair open leveling motor feed circuit if required.4. Ineffective signal circuit.4. Test and repair open or shorted headlamp leveling motor signal circuit if required.5. Ineffective TIPM inputs or outputs.5. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.6. Ineffective motors.6. Test and replace leveling motors if required.As part of the exterior lighting failsafe feature, upon ignition ON, all exterior park lamps and the headlamp low beams will illuminate regardless of the left multi-function switch control knob position if the SCM cannot detect an input from the left multi-function switch, or if there is a loss of communication between the left multi-function switch/SCM and the EMIC or between the EMIC and the TIPM. Diagnose and repair those problems before attempting to repair the Park Lamps.CONDITIONPOSSIBLE CAUSESCORRECTIONPARK LAMP DOES NOT ILLUMINATE1. Ineffective or missing bulb.1. Test and replace park lamp bulb if required.2. Ineffective ground circuit.2. Test and repair open park lamp ground circuit if required.3. Ineffective feed circuit.3. Test and repair open park lamp feed circuit if required.4. Ineffective EMIC (CCN) inputs or outputs.4. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.5. Ineffective TIPM inputs or outputs.5. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.PARK LAMP DOES NOT EXTINGUISH1. Ineffective feed circuit.1. Test and repair shorted park lamp feed circuit if required.2. Ineffective EMIC (CCN) inputs or outputs.2. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.3. Ineffective TIPM inputs or outputs.3. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.The rear fog lamp switch is integral to the left multi-function switch/SCM, which communicates with the EMIC/CCN over the LIN data bus. Before performing any of the following tests, determine whether the other functions of the left multi-function switch/SCM are operational. If the other left multi-function switch/SCM functions are ineffective, diagnose and repair that problem before attempting to repair the Rear Fog Lamps.CONDITIONPOSSIBLE CAUSESCORRECTIONREAR FOG LAMP DOES NOT ILLUMINATE1. Ineffective or missing bulb.1. Test and replace rear fog lamp bulb if required.2. Ineffective ground circuit.2. Test and repair open rear fog lamp ground circuit if required.3. Ineffective feed circuit.3. Test and repair open fog lamp relay control rear circuit if required.4. Ineffective EMIC (CCN) inputs or outputs.4. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.5. Incorrect TIPM configuration.5. Use a diagnostic scan tool to check and correct the TIPM configuration settings if required. Refer to the appropriate diagnostic information.6. Ineffective TIPM inputs or outputs.6. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.REAR FOG LAMP DOES NOT EXTINGUISH1. Ineffective feed circuit.1. Test and repair shorted fog lamp relay control rear circuit if required.2. Ineffective EMIC (CCN) inputs or outputs.2. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.3. Ineffective TIPM inputs or outputs.3. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.The turn signal switch is integral to the left multi-function switch/SCM, which communicates with the EMIC/CCN over the LIN data bus. Before performing any of the following tests, determine whether the other functions of the left multi-function switch/SCM are operational. If the other left multi-function switch/SCM functions are ineffective, diagnose and repair that problem before attempting to repair the Turn Signal Lamps.CONDITIONPOSSIBLE CAUSESCORRECTIONONE TURN SIGNAL LAMP DOES NOT ILLUMINATE1. 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 feed circuit if required.4. Ineffective TIPM inputs or outputs.4. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.ALL RIGHT SIDE OR ALL LEFT SIDE TURN SIGNAL LAMPS (OR BOTH SIDES) DO NOT FLASH1. Ineffective feed circuit.1. Test and repair open right or left turn signal feed circuit if required.2. Ineffective EMIC (CCN) inputs or outputs.2. Use a diagnostic scan tool to test the EMIC (CCN) inputs and outputs. Refer to the appropriate diagnostic information.3. Ineffective TIPM inputs or outputs.3. Use a diagnostic scan tool to test the TIPM inputs and outputs. Refer to the appropriate diagnostic information.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 bulb ground circuit if required.3. Ineffective feed circuit.3. Test and repair open right or left turn signal feed circuit if required.TURN SIGNALS DO NOT AUTOMATICALLY CANCEL1. Ineffective cancel cam.1. Inspect and replace the turn signal cancel cam (clockspring) if required.2. Ineffective cancel actuator.2. Inspect and replace the turn signal cancel actuator (left multi-function switch) if required.