GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

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Important: The Lighting Diagnostic System Check applies to courtesy/illuminated entry lamps only.

Upon verifying the condition, if it is determined that the condition exists in exterior lighting or interior lamps dimming. Refer to the Symptoms - Lighting Systems .

1

Perform the Displaying DTC Codes procedure in order to enter the diagnostic mode and display any DTCs. Refer to On-Board Diagnostic Features in Body Control System.

Did you enter Diagnostic Mode ?

Go to Step 2

Go to Cannot Enter BCM Diagnostics in Body Control System

2

Does the BCM flash any of the following codes:

    • DTC 002
    • DTC 003

Go to Diagnostic Trouble Code (DTC) List

Go to Step 3

3

Does the Body Control Module (BCM) display or sound any other DTCs?

Go to Diagnostic Trouble Code (DTC) List in Body Control System

Go to Symptoms - Lighting Systems