Network
generic / SAE
U0137
Lost Communication with Trailer Brake Control Module
The vehicle network has lost the integrated trailer brake controller. Trailer braking falls back to passive operation; trailer-related warnings appear in the cluster.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number1 / 37
Possible causes
- Trailer module unpowered or fuse blown high
- Gateway module routing CAN messages incorrectly low
- CAN terminating resistor (120 Ω) drifted out of spec low
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
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 60–600 €
- Estimated time: 0.5–3 h
- Component: trailer brake module
- Component: can bus wiring
- MIL / check engine light
Sources
References
sae:J2012