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U02BE Lost Communication With Trailer Backup Assist Control Module

Check engine lightOn
EmissionsNot relevant
Drive cycleNot required
Limp modeNo

The trailer backup assist module steers the tow vehicle in reverse so the trailer follows a curve the driver chooses with a knob; with Ford's Pro Trailer Backup Assist the hitch angle comes from a target sticker filmed by the backup camera or from a trailer-mounted sensor. Ram names its unit TRSCM. For the 2021 Ram 1500, STAR case S2108000067 shows U02BE active in the ABS, power steering and engine controllers while the TRSCM is absent from the CAN C bus; the driver gets a throttle-control service warning, the MIL and at times Rear Park Assist unavailable. The trigger was module software: cutting its power via fuse 53 or the connector restarts it, an update was planned, and a new module does not help. Otherwise only the assist is lost.

Likely causes

Module software hangs and the unit drops off the bus (Ram 1500, 2021)
Fuse, supply or connector of the module faulty
CAN wiring to the module damaged

Symptoms

  • Trailer backup assist unavailable
  • Ram: throttle control message, MIL and rear park assist unavailable
  • Code stored in several modules at once

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–600
Time0.3–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

trailer backup assist modulevehicle bus wiring

Related codes

U05BFU0131U0121

References: static.nhtsa.gov, ford.ca.