Lost Communication With Rear Mode Actuator
The vehicle bus reports loss of communication with smart rear HVAC mode (vent/floor/defrost) actuator. Rear air distribution falls back to a default mode.
Affected components
- Rear mode actuator
- Vehicle bus wiring
Common causes
- High likelihood: Bus wiring open or shorted
- Medium likelihood: Module without power or ground
- Medium likelihood: Module failed
Possible symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Diagnostic notes
- A drive cycle may be required after repair
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.