What does it mean?
B1301 is a Body (airbags, seat belts, body electronics) fault code. It indicates: Steering angle signal fault .
Symptoms
- Stability control, traction control or ABS warning lamps lit alongside the body fault
- Adaptive headlamps, lane keeping and park assist functions disabled
- Steering effort may change if the electric power steering derates itself
- Scan tool shows an implausible or frozen steering angle value with the wheel straight
- Warning message about steering or driver assistance systems
Likely causes
- Steering angle sensor never calibrated after an alignment, steering rack or suspension repair
- Faulty steering angle sensor, usually built into the clockspring assembly
- Clockspring damaged or installed off-centre, breaking the sensor circuit
- Open, shorted or corroded wiring at the steering column connector
- Bus messages from the sensor not reaching the stability control or body module
- Low system voltage disturbing the sensor's zero reference
- Column or intermediate shaft refitted with the sensor out of its centre position
How to fix it
- Read the live steering angle value and compare it with the actual wheel position at dead centre
- Carry out the steering angle sensor calibration first, many cases are nothing more than a lost calibration
- Inspect the clockspring connector and column wiring for pinched or corroded terminals
- Verify supply voltage and ground at the sensor, and check the battery and charging system
- Confirm the wheel speed signals are valid, since some calibration routines depend on them
- Replace the steering angle sensor or clockspring assembly if the value stays frozen or absent
- Recalibrate after any replacement and confirm every assistance system returns to normal on a short road test