What does it mean?
U1041 is a Network (CAN bus, module communications) fault code. It indicates: No Communication With Electronic Brake Control Module .
Symptoms
- ABS, stability control and brake warning lamps permanently on from the moment the ignition is switched on
- ABS and all stability functions completely inoperative
- Speedometer dead or wildly inaccurate if the module supplies wheel speed data
- Scan tool cannot find the brake control module at all
- Electric parking brake or hill hold functions unavailable
- Other modules storing codes for missing brake data
Likely causes
- Blown fuse or failed relay so the brake module has no power
- Broken ground connection at the brake module, leaving the module dead
- Open circuit on one or both bus lines between the brake module and the gateway
- Bus lines shorted together or shorted to ground, stopping all traffic on that segment
- Brake module connector disconnected, badly corroded or damaged during previous work
- Internal brake module failure, including a dead bus transceiver
- Water damage inside the module after long term exposure to road spray
How to fix it
- Try to communicate with the brake module and confirm whether other modules on the same bus still respond, which localises the problem
- Check every fuse and relay in the brake module supply, testing them under load
- Measure battery voltage at the module connector with the ignition on, and check the ground with a voltage drop test
- Inspect the connector for corrosion, water and pushed-out pins; dry and repair the terminals as needed
- Measure resistance across the bus lines at the diagnostic connector and compare it with the expected terminated value
- Test each bus line individually for continuity to the gateway and for shorts to ground and to battery voltage
- Inspect the harness along the wheel arch and chassis for crush damage and corrosion
- Replace and code the electronic brake control module only once power, ground and bus wiring are all proven good