What does it mean?
C1937 is a Chassis (ABS, traction control, steering) fault code. It indicates: Steering Angle Sensor System .
Symptoms
- Stability and traction warning lamps on, usually with the ABS lamp
- Stability control disabled; lane keeping, adaptive lighting and park assist may also stop working
- Steering wheel not centred while driving straight, or a steering symbol shown on the display
- Occasional false stability intervention or a brief brake pull on a straight road
- Warning that appears immediately after suspension, steering or airbag work
Likely causes
- Zero point not learned after an alignment, steering rack, column, clockspring or sensor replacement
- Internal sensor fault: worn or contaminated optical/magnetic disc giving skipped counts
- Damaged clockspring assembly, which carries the sensor supply and signal wiring through the column
- Open circuit, short or high resistance on the sensor supply, ground or data line at the column connector
- Steering wheel refitted off-centre, or the alignment leaves the wheel crooked when the vehicle runs straight
- ABS/ESP module receiving the data is faulty or the network message is corrupted
- Low or unstable system voltage disturbing the sensor
How to fix it
- Read live steering angle with the wheels straight ahead on level ground; it should be close to zero degrees
- Confirm the steering wheel is centred and the wheel alignment is correct before calibrating anything
- Turn the wheel slowly lock to lock while graphing the angle and look for steps, jumps or dropouts
- Inspect the clockspring and the column connector, especially after airbag or column work
- Check the sensor supply voltage, ground and data line for continuity and corrosion
- Perform the steering angle zero point / calibration routine, including the drive test if one is specified
- Replace the sensor, or the clockspring assembly it is built into, if the angle stays frozen or out of range, then recalibrate and road test