U0660 — Lost Communication With Left Rear Temperature Actuator B
The vehicle bus reports loss of communication with smart left-rear HVAC temperature blend door actuator B. Rear-left air temperature falls back to a default position.
General code reference. Confirm the definition and diagnostic procedure for your vehicle's year, model and engine. A stored code alone does not identify a failed part.
Affected components
- Lr temp actuator b
- Vehicle bus wiring
Possible causes to check
These are possible checks, not a ranked diagnosis. Follow the vehicle manufacturer's test procedure before replacing parts.
- Bus wiring open or shorted
- Module without power or ground
- 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
Related codes
Sources
Check each reference's vehicle and model-year scope. General background links do not establish which fault is most likely on your vehicle.
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.