U0165
NetworkModule Communicationlow severityLost Communication with Rear HVAC Control Module
What U0165 Means
Cannot communicate with the rear climate control zone module.
Symptoms
- Rear A/C not working
- Rear climate controls unresponsive
- No rear heat
- Rear blower not running
Common Causes
- Rear HVAC module failure
- CAN bus wiring
- Module power loss
- Fuse blown
- Rear blower motor issue
Diagnostic Steps
- Check rear HVAC module fuse
- Test power and ground
- Check CAN wiring
- Test rear blower motor
- Inspect rear climate control panel
Where to start: Check fuses for rear HVAC system. Rear module wiring runs through pillars.
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