Network
generic / SAE
U0077
Vehicle Communication Bus B Off
A controller on bus B has reached its transmit error limit and shut its transceiver off. All traffic on this segment stops until the cause is removed.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number– / 77
Possible causes
- Persistent wiring fault on bus B high
- Gateway module routing CAN messages incorrectly low
- CAN terminating resistor (120 Ω) drifted out of spec low
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
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 80–800 €
- Estimated time: 1–6 h
- Component: can transceiver
- Component: can bus wiring
- MIL / check engine light
Sources
References
sae:J2012
iso:11898