OBD-II code · Network
U0036 Vehicle Communication Bus A (-) shorted to Bus A (+)
The two lines of differential bus A are shorted together. Communication impossible — both lines see the same voltage.
Is it safe to drive with U0036?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyCAN-H/CAN-L shorted together
- 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
Related codes
- U0045Vehicle Communication Bus B (-) shorted to Bus B (+)
- U0054Vehicle Communication Bus C (-) shorted to Bus C (+)
- U0063Vehicle Communication Bus D (-) shorted to Bus D (+)
- U009AVehicle Communication Bus H (-) shorted to Bus H (+)
- U0033Vehicle Communication Bus A (-) Open
- U0034Vehicle Communication Bus A (-) Low
- U0035Vehicle Communication Bus A (-) High
- U0037Vehicle Communication Bus B
- U0038Vehicle Communication Bus B Performance
- U0039Vehicle Communication Bus B (+) Open
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.