U02BE
Lost Communication With Trailer Backup Assist Control Module
The vehicle bus reports loss of communication with the trailer backup assist module. Steer-by-knob trailer reverse guidance, hitch angle sensing and trajectory planning are unavailable.
- Check engine light: Not always
- Emissions related: No
- Repair difficulty: medium
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
Common causes
Ordered by how often each turns out to be the cause.
- Bus wiring open or shortedCommon
- Module without power or groundPossible
- Module failedPossible
Parts involved
- Trailer Backup Assist Module
- Vehicle Bus Wiring
U02BE is a generic OBD-II code defined by SAE J2012. Exact wording and diagnostic procedure vary by manufacturer and model. Code definitions are drawn from the public-domain OBDex dataset; the workshop notes are our own.