What does it mean?
C1274 is a Chassis (ABS, traction control, steering) fault code. It indicates: Longitudinal G Sensor Open/Short .
Symptoms
- Stability, traction and often ABS warning lamps illuminated
- Hill start assist and hill descent control inoperative
- Longitudinal acceleration value in live data missing, stuck or reading a large offset while stationary
- ABS behaviour becomes coarse on split-friction or downhill surfaces
- All wheel drive torque distribution may default to a fixed strategy
Likely causes
- Open or short circuit in the longitudinal acceleration sensor supply, ground or signal wiring
- Corroded or wet connector at the sensor, which usually sits under the centre console or a front seat
- Harness damage from seat rails, carpet fitting or interior water leaks
- Internal failure of the acceleration sensor
- Loss of the 5 V reference or a poor sensor ground
- Sensor mounting bolts loose or the sensor fitted in the wrong orientation after removal
- Control module input fault
How to fix it
- Locate the sensor and inspect the connector for moisture, corrosion and loose terminals
- With the vehicle level and stationary, read the longitudinal value; it should sit close to zero
- Measure the 5 V reference and ground at the sensor connector with the ignition on
- Disconnect the sensor and test each circuit for open, short to ground and short to voltage back to the module
- Check the mounting bolts and confirm the sensor is fitted the correct way round
- Repair the wiring, then carry out the sensor zero point calibration
- Replace the sensor or sensor cluster if the circuits are good and the output is still invalid