OBD-II code · Network
U0251 Lost Communication With Running Board Control Module B
The vehicle bus reports loss of communication with running board control module B. Power-deploying running boards on the corresponding side stop responding to door-open requests.
Is it safe to drive with U0251?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyBus wiring open or shorted
- PossibleModule without power or ground
- PossibleModule failed
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
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.5–3 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Running Board Module B, Vehicle Bus Wiring
Related codes
- U0244Lost Communication With Running Board Control Module A
- U024ELost Communication With Side Obstacle Detection Control Module C
- U024FLost Communication With Side Obstacle Detection Control Module D
- U0250Lost Communication With Impact Classification System Module
- U0252Lost Communication With Lighting Control Module Rear B
- U0253Lost Communication With Accessory Protocol Interface Module
- U0254Lost Communication With Remote Start Module
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.