What does it mean?
C1259 is a Chassis (ABS, traction control, steering) fault code. It indicates: Steering Angle Sensor - Electrical Malfunction .
Symptoms
- Stability and traction control lamps on with the systems disabled
- Electric power steering assist may become uneven or reduced
- Steering angle in live data reads zero, is stuck or is missing altogether
- ABS warning lamp often on at the same time
- Driver assistance features that need steering angle, such as lane keeping or cornering lights, stop working
Likely causes
- Open, short or high resistance in the steering angle sensor supply, ground or signal wiring
- Worn or broken clockspring (spiral cable) in the steering column
- Corroded, wet or loose sensor connector under the column shroud
- Internal failure of the steering angle sensor itself
- Loss of the 5 V reference, sometimes because another sensor on the shared circuit is shorted
- Harness damage caused by column, airbag or ignition switch work
- Faulty stability control module reading the sensor input
How to fix it
- Read the steering angle value in live data and compare it with the real wheel position; straight ahead should be close to zero degrees
- Inspect the sensor connector and column harness for chafing, moisture and backed-out terminals
- Measure the sensor reference voltage and ground at the connector with the ignition on
- If the reference is dragged low, unplug other sensors on the same circuit one at a time to find the shorted one
- Check the clockspring for continuity through the full lock-to-lock travel
- Repair the wiring, then run the steering angle calibration and see whether the fault clears
- Replace the sensor or the clockspring assembly once the supplies and wiring test good