GM Service Manual Online
For 1990-2009 cars only

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

  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 module(s) can communicate via serial data link.
  3. Review the system description and operation in order to familiarize yourself with the system functions. Refer to the following:
  4. •  Power Windows Description and Operation
    •  Rear Window Defogger Description and Operation

Visual/Physical Inspection

    • Inspect for aftermarket devices which could affect the operation of the power windows or rear window defogger. Refer to Checking Aftermarket Accessories .
    • Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.

Intermittent

Thoroughly inspect the wiring and connectors. An incomplete inspection of the wiring and connectors may result in misdiagnosis causing part replacement with the reappearance of the malfunction. If an intermittent malfunction exists, 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:

    •  Rear Window Defogger Inoperative
    •  Power Window Express Down Function Inoperative
    •  Power Windows Inoperative - One
    •  Power Windows Inoperative - All
    •  Power Window Lockout Function Inoperative