GM Service Manual Online
For 1990-2009 cars only
  1. Perform the Diagnostic System Check - Vehicle , before using the Symptom Tables in order to verify that all of the following are true:
  2. • There are no DTCs set.
    • The control modules 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:
  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 .
    • 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 .

Symptom List

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

    •  Backup Lamps Malfunction
    •  Courtesy Lamps Malfunction
    •  Daytime Running Lamps Malfunction
    •  Front Fog Lamps Malfunction
    •  Hazard Lamps Malfunction
    •  Headlamps Malfunction
    •  Interior Backlighting Malfunction
    •  Park, License, and/or Tail Lamps Malfunction
    •  Stop Lamps Malfunction
    •  Turn Signal Lamps and/or Indicators Malfunction