GM Service Manual Online
For 1990-2009 cars only

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:
  2. • There are no DTCs set.
    • The control module(s) can communicate via the serial data link.
  3. Review the system operation and circuit descriptions that apply to the customer complaint in order to familiarize yourself with the system functions. Refer to the following list:
  4. •  Exterior Lighting Systems Description and Operation
    •  Interior Lighting Systems Description and Operation

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
    •  Courtesy Lamps Always On
    •  Courtesy Lamps Inoperative
    •  Daytime Running Lamps (DRL) Inoperative
    •  Daytime Running Lamps (DRL) On with Headlamp Switch On
    •  Daytime Running Lamps (DRL) On with Park Brake Applied
    •  Fog Lamp Indicator Always On
    •  Fog Lamp Indicator Inoperative
    •  Fog Lamps Always On
    •  Rear Fog Lamps Always On
    •  Fog Lamps Inoperative
    •  Rear Fog Lamps Inoperative
    •  Hazard Lamps Inoperative
    •  Low and High Beams Headlamps Inoperative
    •  Headlamps Inoperative - Low Beams
    •  Headlamps Inoperative - High Beams
    •  Headlamps Inoperative in Low Light Conditions
    •  Headlight Leveling Inoperative
    •  High Beam Indicator Always On
    •  High Beam Indicator Inoperative
    •  Interior Backlighting Does Not Dim
    •  Interior Backlighting Inoperative
    •  Instrument Panel Compartment Lamp Inoperative
    •  Instrument Panel Compartment Lamp Always On
    •  License Lamps Inoperative
    •  Marker Lamps Inoperative
    •  Park Lamps Inoperative
    •  Tail, Marker, and License Lamps Always On
    •  Tail, Marker, and License Lamps Inoperative
    •  Repeater Lamps Inoperative
    •  Stop Lamps Always On
    •  Stop Lamps Inoperative
    •  Tail Lamps Inoperative
    •  Turn Signal Lamps and/or Indicators Always On or Flashing
    •  Turn Signal Lamps and/or Indicators Inoperative
    •  Underhood Lamp Inoperative
    •  Vanity Mirror Lamp Inoperative