Network
generic / SAE
U0046
Vehicle Communication Bus C
Generic fault on bus C (third bus, often chassis CAN or diagnostic CAN). A communication loss with this module breaks any function relying on its data — diagnostic tools may show 'no response' and dependent modules can fall into limp mode.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number– / 46
Possible causes
- Wiring or node fault on bus C 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: 100–1500 €
- Estimated time: 1–6 h
- Component: bus c wiring
- Component: bus c nodes
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012