GM Service Manual Online
For 1990-2009 cars only

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

  1. Perform the Diagnostic System Check - Lighting Systems before using the Symptom Tables in order to verify that all of the following are true:
  2. • There are no DTCs set.
    • The control module(s) can communicate via the serial data link.
  3. Review the system operation in order to familiarize yourself with the system functions. Refer to:
  4. •  Headlights/Daytime Running Lights (DRL) Circuit Description
    •  Fog Lights Circuit Description
    •  Headlight Doors Circuit Description
    •  Exterior Lights Circuit Description
    •  Interior Lights Circuit Description
    •  Interior Lights Dimming Circuit Description

Visual/Physical Inspection

    • 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 for obvious damage or conditions which could cause the symptom.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections in Wiring Systems.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom:

    •  Backup Lamps Always On
    •  Backup Lamps Inoperative
    •  Component Illumination Lamps Inoperative
    •  Component Illumination Lamps Inoperative
    •  Component Illumination Lamps Inoperative
    •  Component Illumination Lamps Inoperative
    •  Courtesy Lamps Inoperative
    •  Daytime Running Lamps (DRL) Headlamps Inoperative
    •  Daytime Running Lamps (DRL) Headlamps Inoperative
    •  Fog Lamp Indicator Inoperative
    •  Fog Lamps Always On
    •  Rear Fog Lamps Always On
    •  Fog Lamps Inoperative - All
    •  Rear Fog Lamps Inoperative
    •  Fog Lamp Switch Illumination Lamp Inoperative
    •  Hazard Lamps Inoperative
    •  Headlamps Inoperative - Low Beams
    •  Headlamps Inoperative - High Beams
    •  Headlamps Inoperative - One Lamp
    •  Low and High Beams Headlamps Inoperative
    •  Headlamp Doors Inoperative - One Door
    •  Headlamp Doors Do Not Open
    •  Headlamp Doors Do Not Close
    •  Instrument Panel Lamps Erratic with Dimmer Switch
    •  Park Lamps Inoperative - Rear
    •  Park, Tail and Side Marker Lamps Inoperative
    •  Stop Lamps Inoperative
    •  Stop Lamps Inoperative - Center High Mounted Stop Lamp Operates
    •  Stop Lamps Inoperative - Center High Mounted
    •  Turn Signal Lamps Inoperative
    •  Turn Signal Lamps Inoperative
    •  Turn Signal Lamps Inoperative
    •  Turn Signal Lamps Inoperative
    •  Turn Signal Lamps Inoperative