U0071
Vehicle Communication Bus A (+) Bus Off
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.
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.
Common causes
- high
Persistent short on the CAN-H wire
One of the most commonly reported causes for this code — check this first.
Typical part cost: $90-880
- medium
One module driving bus permanently dominant
A plausible cause — test and verify before replacing parts.
Typical part cost: $90-880
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First things to check
- 1Confirm the code with a scan tool and check for additional related codes.
- 2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.
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Related codes
See related trouble codes
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Frequently asked questions
What does U0071 mean?
U0071 means "Vehicle Communication Bus A (+) Bus Off". It is a generic OBD-II code that points to a fault in the network / communication.
What are the most common causes of U0071?
persistent short on the can-h wire; one module driving bus permanently dominant; gateway module routing can messages incorrectly — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.
Can I keep driving with this code?
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly. Use the Wrenchify app for a full diagnosis specific to your vehicle.
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