BMW DTC U04B4 – Invalid Data Received From Brake Blending Actuator
DTC U04B4 meaning on BMW
The DTC U04B4 on a BMW indicates that the vehicle’s onboard diagnostic system has detected invalid data being received from the Brake Blending Actuator. This means that there is a communication issue between the control module and the brake blending actuator, which can affect the proper functioning of the braking system.
BMW DTC U04B4 symptoms
Symptoms of the DTC U04B4 on a BMW may include:
- ABS warning light illuminated on the dashboard
- Brake system malfunction warning message
- Loss of brake blending functionality
- Decreased braking performance
BMW DTC U04B4 causes
The common causes of the DTC U04B4 on a BMW include:
- Faulty brake blending actuator
- Wiring or connection issues between the control module and the actuator
- Software or programming errors
BMW DTC U04B4 seriousness
The DTC U04B4 is a serious issue as it directly affects the proper functioning of the braking system. Ignoring this fault code can lead to safety hazards and compromised braking performance, which can pose a risk to the driver and passengers.
How to diagnose DTC U04B4 on BMW
To diagnose the DTC U04B4 on a BMW, a mechanic would typically perform the following steps:
- Use a diagnostic scanner to retrieve the fault codes stored in the vehicle’s system
- Inspect the wiring and connections between the control module and the brake blending actuator
- Check the brake blending actuator for any signs of damage or malfunction
- Perform a functionality test on the brake blending system
How to fix DTC U04B4 on BMW
To fix the DTC U04B4 on a BMW, the following steps may be taken:
- Repair or replace any damaged wiring or connections
- Replace the faulty brake blending actuator if necessary
- Update the control module software to the latest version
- Perform a system reset and calibration of the brake blending system
How to erase DTC U04B4 on BMW
To erase the DTC U04B4 on a BMW, the fault code can be cleared using a diagnostic scanner. After the necessary repairs have been made and the issue resolved, the fault code can be cleared to reset the system and turn off the warning lights on the dashboard.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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