GM Service Manual Online
For 1990-2009 cars only

Important: Complete the following steps 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 conditions are true:
  2. • No DTCs are 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 the following procedures:
  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
    •  Fog Lamp Indicator Inoperative
    •  Fog Lamps Always On
    •  Fog Lamps Inoperative
    •  Hazard Lamps Always On
    •  Hazard Lamps Inoperative
    •  Headlamp Opening Door Inoperative
    •  Headlamps Inoperative - Low Beams
    •  Headlamps Inoperative - High Beams
    •  Low and High Beams Headlamps Inoperative
    •  High Beam Indicator Inoperative
    •  Instrument Panel Compartment Lamp Inoperative
    •  Park Lamps Inoperative
    •  Inside Rearview Mirror Lamp Inoperative
    •  Stop Lamps Always On
    •  Stop Lamps Inoperative
    •  Turn Signal Lamps and/or Indicators Inoperative
    •  Twilight Sentinel Inoperative
    •  Underhood Lamp Inoperative
    •  Vanity Mirror Lamp Inoperative