Code result
U066C
Lost Communication With Exhaust Heat Exchanger Bypass Valve Actuator B
Moderate severity
What it means
The vehicle bus reports loss of communication with smart exhaust heat exchanger bypass valve actuator B. Exhaust-heat recovery cannot be commanded; cabin/coolant warm-up may slow down.
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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