For 1990-2009 cars only
Important: Review the automatic day-night mirror system description and operation in order to familiarize yourself with the system functions. Refer to Automatic Day-Night Mirror Description and Operation .
The following steps must be completed before using the symptom tables.- Perform the Diagnostic System Check - Vehicle before using the symptom tables in order to verify that all of the following are true:
- Review the rear window defogger system description and operation in order to familiarize yourself with the system functions. Refer to Rear Window Defogger Inoperative .
| • | There are no DTCs set. |
| • | The control module(s) can communicate via GMLAN serial data. |
Visual/Physical Inspection
| • | Inspect for aftermarket devices which could affect the operation of the rear window defogger or the automatic day-night feature of the inside rearview mirror. 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:
