For 1990-2009 cars

Important: The following steps must be completed before using the symptom tables.

1. Perform Diagnostic System Check - Lighting Systems before using the symptom tables in order to verify that all of the following are true:

• | There are no DTCs set.

• | The body control module (BCM) can communicate via the serial data link.

2. Review the system operation in order to familiarize yourself with the system functions. Refer to the following:

• | Exterior Lighting Systems Description and Operation

• | Interior Lighting Systems Description and Operation

### 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. Refer to Checking Aftermarket Accessories in Wiring Systems.

• | 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. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

### Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose a symptom that does not set a DTC:

• | Backup Lamps Always On

• | Backup Lamps Inoperative

• | Courtesy Lamps Always On

• | Courtesy Lamps Inoperative

• | Daytime Running Lamps (DRL) Indicator Inoperative

• | Fog Lamps Always On

• | Fog Lamps Inoperative

• | Hazard Lamps Inoperative

• | Headlamps Inoperative - Low Beams

• | Headlamps Inoperative - High Beams

• | Low and High Beams Headlamps Inoperative

• | Headlamps Flash to Pass Inoperative

• | High Beam Indicator Inoperative

• | Park Lamps Inoperative

• | Rear Compartment Lamp Inoperative

• | Reading Lamp Inoperative

• | Stop Lamps Inoperative

• | Turn Signal Lamps and/or Indicators Inoperative