U0252Lost Communication With Lighting Control Module - Rear B
- Generic OBD-II code · Network
- How the car detects it
- Module B for rear lighting is the second unit driving lamps at the back end, and in practice it is often the trailer electronics. GM's code list for the 2011 Saab 9-5 assigns U0252 to the trailer interface control module. Ford does the same: on 2021-2023 F-150, 2022-2024 F-150 Lightning, Expedition, Navigator and the 2024 Ranger, the body control module, cluster or steering module records U0252, often with U0137, when the trailer module (TRM) drops off CAN; a five-minute power-down and new TRM software cured it (SSM 53236). Super Duty trucks of 2023-2025 showed the same pair when ground point G201 was not torqued correctly (SSM 53980), and a BCM self-test may leave a harmless U0252:87 history entry (SSM 51578). Trailer lamps or trailer brake messages fail; no MIL.
- What you may notice
- Trailer brake module fault or trailer warning in the cluster
- Trailer lamps or rear lighting functions inoperative
- Further U codes such as U0137 in body control module, cluster or steering module
- Likely causes
- LikelyTrailer or rear lighting module stuck off the bus, software needs reset or update (Ford TRM)
- PossibleLoose or badly tightened body ground shared with the module (Ford G201)
- PossibleDamaged or corroded harness and connectors at the rear or tow bar area
- RareStored history entry from a module self-test without a real fault
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.