U0204
NetworkModule Communicationlow severityLost Communication with Mirror Control Module
What U0204 Means
Cannot communicate with the power mirror or auto-dimming mirror control module.
Symptoms
- Mirror adjustment not working
- Auto-dimming not functioning
- Mirror memory not working
- Auto-fold mirrors disabled
Common Causes
- Mirror module failure
- Wiring issue
- Module power loss
- Fuse blown
- Mirror motor failure
Diagnostic Steps
- Check mirror module fuse
- Test power and ground
- Inspect door jamb wiring
- Test mirror motors
- Check mirror switch
Where to start: Check door jamb wiring. Mirror wiring passes through flex point and commonly breaks.
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