Network
generic / SAE
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.
SystemNetwork
Typegeneric / SAE
GroupU0
Range / number4 / 38
Possible causes
- EPB actuator/motor marginal high
- EPB internal computation fault medium
- Gateway module routing CAN messages incorrectly 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: hard
- DIY: shop recommended
- Estimated cost: 120–1500 €
- Estimated time: 1–4 h
- Component: park brake module
- Component: can bus wiring
- MIL / check engine light
Sources
References
sae:J2012