What does code U04B4 mean?

Q: What does code U04B4 mean?

Invalid Data Received From Brake Blending Actuator. The U04B4 code means the vehicle's computers have lost valid communication with the brake blending actuator, which is the component that coordinates friction braking with regenerative braking on hybrid and electric vehicles. The control module that monitors this actuator expected a regular data message but received missing, corrupted, or out-of-range information, so it flagged the fault and illuminated the warning light.

DTC codes / U04xx · Invalid data received from a module / U04B4

U04B4Invalid Data Received From Brake Blending Actuator

The U04B4 code means the vehicle's computers have lost valid communication with the brake blending actuator, which is the component that coordinates friction braking with regenerative braking on hybrid and electric vehicles. The control module that monitors this actuator expected a regular data message but received missing, corrupted, or out-of-range information, so it flagged the fault and illuminated the warning light.

SystemNetwork

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyProfessional

AreaInvalid data received from a module

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.