Code result
U0646
Lost Communication With Motor Electronics Coolant Pump A
High severity
What it means
The vehicle bus reports loss of communication with smart motor electronics coolant pump A. Cooling for the drive motor inverter cannot be commanded; derating may follow.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
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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