Code result
U0071
Vehicle Communication Bus A (+) Bus Off
High severity
What it means
The CAN controller for bus A has shut its plus driver after exceeding the SAE J2284 / ISO 11898 transmit error threshold. The node disconnects from the bus until error counters recover.
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
Persistent short on the CAN-H wire
highOne of the most commonly reported causes for this code — check this first.
One module driving bus permanently dominant
mediumA plausible cause — test and verify before replacing parts.
Gateway module routing CAN messages incorrectly
lowLess common, but worth ruling out after the more likely causes.
Related help
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