OBD-II code · Network
U04B5 Invalid Data Received From Brake System Control Module B
A receiving module detected implausible data from brake system control module B (secondary brake controller in twin-system architectures). Pressure, slip or pedal-feel values fail plausibility checks and are rejected.
Is it safe to drive with U04B5?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyModule internal fault or sensor input drift
- PossibleSoftware version mismatch after replacement
- 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
- 1–5 h
- Emissions test
- Usually unaffected
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Brake System Module B
Related codes
- U04B2Invalid Data Received From Particulate Matter Sensor B
- U04B3Invalid Data Received From Planetary Gear Set Control Module
- U04B4Invalid Data Received From Brake Blending Actuator
- U04B6Invalid Data Received From Catalyst Heater Control Module
- U04BAInvalid Data Received From Switch Input Module A
- U04BBInvalid Data Received From Switch Input Module B
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.