OBD-II code · Network
U0438 Invalid Data Received from Park Brake Control Module
The Park Brake Control Module is present on the data bus but the values it reports are implausible — out of range, frozen, or failing the checksum or rolling-count check. The receiving modules reject the data. Electronic parking-brake operation may be limited. Causes include a faulty sensor feeding the module, internal computation errors, a software or calibration mismatch after a repair, or bus interference corrupting the frames.
Is it safe to drive with U0438?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyEPB actuator/motor marginal
- PossibleEPB internal computation fault
- Less likelyGateway module routing CAN messages incorrectly
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
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Usually unaffected
- Parts involved
- Park Brake Module, Can Bus Wiring
Related codes
- U0435Invalid Data Received From Power Steering Control Module — Rear
- U0436Invalid Data Received From Differential Control Module — Front
- U0437Invalid Data Received From Differential Control Module — Rear
- U0439Invalid Data Received From All Terrain Control Module
- U043AInvalid Data Received From Suspension Control Module B
- U043BInvalid Data Received From Front Distance Range Sensor — Left
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.