OBD-II code · Network
U0072 Vehicle Communication Bus A (-) Bus Off
The CAN controller for bus A has gone bus-off on the minus side. Common after a CAN-L short or a faulty transceiver pulling the bus low.
Is it safe to drive with U0072?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyPersistent short on CAN-L wire
- Less likelyGateway module routing CAN messages incorrectly
- Less likelyCAN terminating resistor (120 Ω) drifted out of spec
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–6 h
- Emissions test
- Usually unaffected
- Parts involved
- Can Transceiver, Can Low Wire
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.