Code result
U0663
Lost Communication With Rear Mode Actuator
Moderate severity
What it means
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.
Is it safe to drive?
Use caution
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
Bus wiring open or shorted
highOne of the most commonly reported causes for this code — check this first.
Module without power or ground
mediumA plausible cause — test and verify before replacing parts.
Module failed
mediumA plausible cause — test and verify before replacing parts.
Related help
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