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.
Affected components
- Can transceiver
- Can high wire
Common causes
- High likelihood: Persistent short on the CAN-H wire
- Medium likelihood: One module driving bus permanently dominant
- Low likelihood: Gateway module routing CAN messages incorrectly
Possible symptoms
- Multiple warning lights may illuminate
- Affected modules may go into limp mode or shut down
- Specific functions inoperative depending on module
- Diagnostic tools may show communication faults
Diagnostic notes
- The malfunction indicator lamp may illuminate
- Reduced-power or limp mode may occur
Sources
Diagnostic information is provided for reference only. Confirm the code with a compatible scan tool and follow the vehicle manufacturer's service procedures before replacing components.