U0438Invalid Data Received From Trailer Brake Control Module
- Generic OBD-II code · Network
- How the car detects it
- U0438 names the trailer brake control module, which applies the electric brakes of a towed trailer in step with the vehicle's braking; park brake data has a code of its own, U0417. Ford uses U0438 explicitly: SSM 52184 connects U0438:82 stored by the cluster of some 2023 F-150 PowerBoost hybrids, built from 24 to 26 October 2022, with a Trailer Brake System Fault message caused by the cluster configuration, which is re-run with the dealer tool. SSM 53980 for 2023-25 Super Duty blames U0438 together with other network codes on an incorrectly tightened ground G201 (8 ± 1.2 Nm). Saab's 2011 9-5 list knows subtype 71. The driver sees a trailer brake warning and gain control may not work. U0137 is lost contact.
- What you may notice
- Trailer brake system fault message
- Trailer brake gain cannot be set or trailer brakes inactive
- Further network warnings in the cluster
- Likely causes
- LikelyReceiving module (instrument cluster) wrongly configured
- PossibleLoose or wrongly tightened body ground
- RareInternal fault of the trailer brake control module
- Repair
- Medium · Usually a job for a workshop.Typical cost: €40 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.