Network
generic / SAE
U0033
Vehicle Communication Bus A (-) Open
The communication bus A low-side line (CAN-L) is open — broken wire, unplugged connector, or terminator missing.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number– / 33
Possible causes
- CAN-L wire broken or unplugged 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: 80–1000 €
- Estimated time: 1–5 h
- Component: bus a wiring
- Component: bus a terminator
- MIL / check engine light
- limp mode possible
Sources
References
sae:J2012