Automatic Inside Dimming Mirror Test/Replacement
Test/ReplacementNOTE: Before testing, check the No.13 (7.5 A) fuse. No. 7, 10, 11, 13, 14 and 15 terminals are OnStar switches microphone power, ground and signal lines.
1. Disconnect the 15P connector from the mirror.
2. Check for voltage between the No.12 terminal and body ground with the ignition switch ON (II).
- If there is battery voltage, go to step 3.
- If there is no voltage, check for:
- an open in the wire, or
- poor ground (G401, G402).
3. Check for voltage between the No.16 terminal and body ground with the ignition switch ON (II) and A/T gear position in [R].
- If there is battery voltage, replace the mirror by removing torx screw.
- If there is no voltage, check for:
- an open in the wire, or
- faulty reverse relay, or
- faulty transmission range switch, or
- faulty diode.