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 in order to familiarize yourself with the system functions. Refer to the following list:
  4. •  Headlights Circuit Description
    •  Headlights/Daytime Running Lights (DRL) Circuit Description
    •  Exterior Lights Circuit Description
    •  Backup Lamp 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
    •  Backup Lamp Inoperative - One Lamp
    •  Courtesy or Dome Lamps Always On
    •  Courtesy or Dome Lamps Inoperative
    •  Daytime Running Lamps (DRL) Headlamps Always On
    •  Daytime Running Lamps (DRL) Headlamps Inoperative
    •  Hazard Lamps Inoperative
    •  Headlamps Inoperative - Left Low Beam
    •  Headlamps Inoperative - Right Low Beam
    •  Headlamps Inoperative - Low Beams
    •  Headlamps Inoperative - Left High Beam
    •  Headlamps Inoperative - Right High Beam
    •  Headlamps Inoperative - High Beams
    •  Headlamps Inoperative in Low Light Conditions
    •  High Beam Indicator Always On
    •  High Beam Indicator Inoperative
    •  Instrument Cluster Illumination Lamps Always On
    •  Instrument Cluster Illumination Lamps Inoperative
    •  Instrument Panel Compartment Lamp Inoperative
    •  Vanity Mirror Lamp Inoperative
    •  Underhood Lamp Inoperative
    •  Instrument Panel Lamps Inoperative
    •  Park Lamps Inoperative - Front
    •  Park Lamps Inoperative in Low Light Conditions
    •  Park, Tail and Side Marker Lamps Inoperative
    •  Inside Rearview Mirror Lamp Inoperative
    •  Tail, Marker, and License Lamps Inoperative
    •  Stop Lamps Inoperative
    •  Stop Lamps Inoperative - One
    •  Stop Lamps Inoperative - Center High Mounted
    •  Tail Lamp Inoperative - Left Rear
    •  Tail Lamps Inoperative - Right Rear
    •  Turn Signal Lamps Inoperative
    •  Turn Signal Lamp Inoperative - Left Side Front
    •  Turn Signal Lamp Inoperative - Right Side Front
    •  Turn Signal Lamps Inoperative - Left Side Rear
    •  Turn Signal Lamp Inoperative - Right Side Rear
    •  Turn Signal Indicator Always On - Left Side
    •  Turn Signal Indicator Always On - Right Side
    •  Turn Signal Indicators Inoperative - Left Side
    •  Turn Signal Indicators Inoperative - Right Side