Test A: Inside Automatic Day/Night Mirror Inoperative
NOTE:
Reviewing system description and operation information will help determine if condition described by customer is normal operation, and may help determine correct symptom diagnostic procedure when a malfunction exists.
- If automatic day/night mirror system description and operation has been reviewed, go to next step. If description and operation has not been reviewed, see DESCRIPTION & OPERATION .
- If vehicle is equipped with left outside automatic day/night mirror, go to next step. If vehicle is not equipped with left outside automatic day/night mirror, go to step 4 .
- Turn ignition switch to RUN position. Turn off inside rearview mirror automatic day/night feature. If inside rearview mirror and left outside rearview mirror do not remain in a darkened state, to next step. If inside rearview mirror and left outside rearview mirror remain in a darkened state, go to step 12 .
- Turn on inside rearview mirror automatic day/night feature. Cover sensor on inside rearview mirror back (facing front window). Shine a bright light into sensor on inside rearview mirror face (facing rear window). If inside rearview mirror does not darken, go to next step. If inside rearview mirror darkens, go to DIAGNOSING INTERMITTENTS .
- Turn ignition switch to OFF position. Disconnect inside rearview mirror harness connector. Measure resistance between ground and inside rearview mirror 7-pin harness connector terminal No. 2 (Black wire) or 16-pin harness connector terminal No. 8 (Black wire). See Fig 1 or Fig 2 . If resistance is less than 3 ohms, go to next step. If resistance is 3 ohms or more, go to step 13 .
- Turn ignition switch to RUN position. Measure voltage between inside rearview mirror 7-pin harness connector terminals No. 1 (Brown wire) and No. 2 (Black wire) or between 16-pin harness connector terminals No. 8 (Black wire) and No. 13 (Brown wire). If battery voltage is present, go to next step. If battery voltage is not present, go to step 14 .
- Place transmission in Park. Measure voltage between inside rearview mirror 7-pin harness connector terminals No. 2 (Black wire) and No. 3 (Light Green wire) or between 16-pin harness connector terminals No. 8 (Black wire) and No. 9 (Light Green wire). If voltage less than 5 volts, go to next step. If voltage is 5 volts or more, repair back-up lights as necessary. See appropriate wiring diagram in EXTERIOR LIGHTS article.
- Place transmission in Reverse. Measure voltage between inside rearview mirror 7-pin harness connector terminals No. 2 (Black wire) and No. 3 (Light Green wire) or between 16-pin harness connector terminals No. 8 (Black wire) and No. 9 (Light Green wire). If battery voltage is not present, go to next step. If battery voltage is present, go to step 10 .
- Test Light Green wire between underhood fuse block and inside rearview mirror harness connector for an open or high resistance. See WIRING DIAGRAMS . If an open or high resistance is not found, repair back-up lights as necessary. See appropriate wiring diagram in EXTERIOR LIGHTS article. If an open or high resistance is found, repair as necessary. After repair, go to step 16 .
- Test Gray wire between inside rearview mirror and left outside rearview mirror for short to ground. See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article. If short to ground is not found, go to next step. If short to ground is found, go to step 16 .
- Check for poor connections at inside rearview mirror connectors. If poor connections are not found, go to step 15 . If poor connections are found, repair as necessary. After repair, go to step 16 .
- Repair short to voltage in Gray wire between inside rearview mirror and left outside rearview mirror. See appropriate wiring diagram in ILLUMINATION/INTERIOR LIGHTS article. After repair, go to step 16 .
- Repair open or high resistance in Black wire between inside rearview mirror and ground point. Ground point is located in trunk, below right of rear window trim panel. After repair, go to step 16 .
- Repair open or short to ground in Brown wire between inside rearview mirror and instrument panel fuse block. After repair, go to step 16 .
- Replace inside rearview mirror. See INSIDE REARVIEW MIRROR under REMOVAL & INSTALLATION. After repair, go to next step.
- Operate system to verify repair. If system does not operate properly, go to step 2 . If system operates properly, system is okay.
NOTE:
Inside rearview mirror harness connector on vehicles without OnStar(R) is a 7-pin connector. Inside rearview mirror harness connector on vehicles with OnStar(R) is a 16-pin connector.