OBD-II code · Network
U0037 Vehicle Communication Bus B
Generic fault on vehicle communication bus B (second physical bus, e.g. body CAN, comfort CAN, or LIN). One or more nodes cannot communicate.
Is it safe to drive with U0037?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyWiring or node fault on bus B
- 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 B Wiring, Bus B Nodes
Related codes
- U0028Vehicle Communication Bus A
- U0029Vehicle Communication Bus B
- U0046Vehicle Communication Bus C
- U0055Vehicle Communication Bus D
- U0064Vehicle Communication Bus E
- U0089Vehicle Communication Bus G
- U009BVehicle Communication Bus I
- U009DVehicle Communication Bus J
- U0034Vehicle Communication Bus A (-) Low
- U0035Vehicle Communication Bus A (-) High
- U0036Vehicle Communication Bus A (-) shorted to Bus A (+)
- U0038Vehicle Communication Bus B Performance
- U0039Vehicle Communication Bus B (+) Open
- U0040Communication Bus Off
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.