U01B4
Lost Communication With Brake System Control Module B
U01B4 is an OBD-II diagnostic trouble code meaning: Lost Communication With Brake System Control Module B. Common causes: broken or damaged can bus wires, brake control module b malfunction. Estimated repair cost: $56–278.
Symptoms
- Check Engine Light Is On
- Disabling the ABS/ESP system
- Other related errors appear
- Unstable operation of the brake system
- Problems with cruise control
Causes
- Broken or damaged CAN bus wires
- Brake control module B malfunction
- Connector problems or contact corrosion
- Blown fuse
- Software error in the ECU
How to Fix
- Check the integrity of the wiring harness to the module
- Inspect and clean connector contacts
- Check and replace fuses
- Scan all modules for other errors
- Repair only from an authorized dealer
Related codes
Error U01B4 by Vehicle Brand
FAQ
What does the U01B4 code mean?
U01B4 is an OBD-II diagnostic trouble code that indicates: Lost Communication With Brake System Control Module B
What causes a U01B4 error code?
The most common causes of U01B4 include: Broken or damaged CAN bus wires; Brake control module B malfunction; Connector problems or contact corrosion; Blown fuse.
How do I fix a U01B4 diagnostic trouble code?
To fix U01B4: Check the integrity of the wiring harness to the module. Inspect and clean connector contacts. Check and replace fuses. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with U01B4?
Do not drive — repair immediately
How much does it cost to fix U01B4?
The estimated repair cost for U01B4 is $56–278. Actual cost depends on your vehicle, location, and labor rates.
See also: Russian version · NationStat