OBD-II code · Network
U0035 Vehicle Communication Bus A (-) High
Bus A low-side line voltage above the expected range. Short to power or transceiver fault. 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.
Is it safe to drive with U0035?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyCAN-L shorted to battery
- 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
- Bus A Wiring, Bus A Transceiver
Related codes
- U0044Vehicle Communication Bus B (-) High
- U0053Vehicle Communication Bus C (-) High
- U0062Vehicle Communication Bus D (-) High
- U0090Vehicle Communication Bus G (-) High
- U0099Vehicle Communication Bus H (-) High
- U0032Vehicle Communication Bus A (+) High
- U0033Vehicle Communication Bus A (-) Open
- U0034Vehicle Communication Bus A (-) Low
- U0036Vehicle Communication Bus A (-) shorted to Bus A (+)
- U0037Vehicle Communication Bus B
- U0038Vehicle Communication Bus B Performance
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.