What does it mean?
U1120 is a Network (CAN bus, module communications) fault code. It indicates: Lost Communication With Steering Angle Sensor Module .
Symptoms
- ABS, traction control and stability control warning lamps on together
- Stability control switched off, with no intervention in slippery corners
- Steering assist reduced or heavier steering effort on vehicles with electric power steering
- Lane keeping, parking assistance or adaptive lighting unavailable
- Steering wheel buttons, horn or airbag warning behaving oddly when the clockspring is the cause
- The steering angle value in live data is missing, frozen or wildly wrong
Likely causes
- Faulty clockspring or spiral cable in the steering column, which carries the sensor signals across the rotating joint
- Loose, corroded or partly unlatched connector at the sensor or in the column harness
- Open or shorted bus wiring between the steering angle sensor and the ABS or stability control module
- Missing power feed or ground at the sensor module, or a blown fuse
- Steering angle sensor never calibrated after an alignment, steering rack repair or battery disconnection
- Internal failure of the sensor unit itself
- Water reaching the column area after a windscreen or heater core leak
How to fix it
- Read live data for steering angle while turning the wheel slowly lock to lock and watch for dropouts or a stuck value
- Inspect the clockspring and its connectors, since a broken conductor there also affects horn and wheel controls
- Check power feed, ground and the relevant fuse at the sensor module
- Test the bus wiring between the sensor and the stability control module for continuity and shorts
- Look for water damage or corrosion in the lower column harness
- Perform the steering angle sensor calibration and a straight-ahead learn procedure after any repair or alignment
- Replace the clockspring or the sensor module only after wiring, supply and calibration have been ruled out