GM Service Manual Online
For 1990-2009 cars only

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

  1. Perform the Body Control Module (BCM) Diagnostic System Check 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.
  4. Refer to Body Control System Operation .

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the BCM 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 Inoperative in Lighting Systems
    •  Cornering Lamps Inoperative in Lighting Systems
    •  Courtesy Lamps Inoperative in Lighting Systems
    •  Reading Lamp Inoperative in Lighting Systems
    •  Daytime Running Lamps (DRL) Headlamps Inoperative in Lighting Systems
    •  Fog Lamp Indicator Inoperative in Lighting Systems
    •  Hazard Lamps Inoperative in Lighting Systems
    •  Headlamps Inoperative - Low Beams in Lighting Systems
    •  Headlamps Inoperative - High Beams in Lighting Systems
    •  Headlamps Flash to Pass Inoperative in Lighting Systems
    •  High Beam Indicator Inoperative in Lighting Systems
    •  Instrument Panel Compartment Lamp Inoperative in Lighting Systems
    •  Vanity Mirror Lamp Inoperative in Lighting Systems
    •  Rear Compartment Lamp Inoperative in Lighting Systems
    •  Incandescent Lamps Do Not Dim in Lighting Systems
    •  Turn Signal Indicators Inoperative in Lighting Systems
    •  Twilight Sentinel Inoperative in Lighting Systems