What does it mean?
C1275 is a Chassis (ABS, traction control, steering) fault code. It indicates: Longitudinal G Sensor Range/Performance error .
Symptoms
- Stability and traction lamps on, often only after a period of driving
- Hill start assist releasing too early or not holding at all
- Longitudinal value not close to zero with the vehicle level and stationary
- Stability system intervening late, weakly or not at all under hard braking
- Fault more likely to appear on hills or during heavy braking
Likely causes
- Longitudinal acceleration sensor drifted so its output no longer matches vehicle behaviour
- Sensor never zeroed after it, the module or the suspension was worked on
- Loose mounting bolts or a sensor fitted at a slight angle, giving a constant offset
- Ride height wrong because of sagging springs, overloading or an incorrect suspension repair
- Mismatched tyre sizes or a dragging brake so the module sees deceleration that the sensor does not confirm
- Internal sensor fault producing a value that is in range but implausible
- Chassis module comparing the sensor against faulty wheel speed or brake pressure data
How to fix it
- Park on a genuinely level surface and read the longitudinal acceleration value; it should be very near zero
- Check the sensor mounting bolts and the orientation marks before anything else
- Confirm ride height, spring condition and load are normal, and that all four tyres match
- Check for a dragging brake or a wheel speed sensor fault that could make the comparison fail
- Compare the longitudinal reading with lateral acceleration and yaw values during a road test
- Carry out the zero point calibration for the sensor and retest
- Replace the sensor or the sensor cluster if the value stays offset after calibration