Exterior Lamps And Lighting: Notes

WARNING:

To avoid serious or fatal injury on vehicles equipped with airbags, disable the Supplemental Restraint System (SRS) 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 SRS. 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 dim or flickering bulbs can be caused by low generator output or poor battery condition. If any of these symptoms are present, diagnose the battery and charging system, and 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.

WARNING:

On vehicles equipped with the high voltage system, disconnecting the 12-volt battery negative cable alone will not power down the 12-volt system. You must perform the 12-volt Power Down procedure before proceeding. Failure to follow these instructions may result in possible serious or fatal injury.

The lamps and the hardwired circuits between components related to the exterior lighting system may be diagnosed using conventional diagnostic tools and procedures. The wiring information includes wiring diagrams, details of wire harness routing and retention, connector pin-out information and location views for the various wire harness connectors, splices and grounds. For proper wire repair, and connector repair procedures. Refer to CIRCUIT LOAD TESTING PROCEDURES , CONNECTOR TERMINAL REMOVAL and CONNECTOR TERMINAL INSTALLATION .

ACRONYMS USED IN THE FOLLOWING SERVICE INFORMATION
Body Control Module	BCM
Center High-Mounted Stop Lamp	CHMSL
Daytime Running Lamps	DRL
Instrument Panel Cluster	IPC
Integrated Center Stack	ICS
Transmission Range Sensor	TRS

Perform the following troubleshooting steps in the symptom based diagnostic tables to help diagnose any exterior lighting concerns: