What does it mean?
C1146 is a Chassis (ABS, traction control, steering) fault code. It indicates: Yaw Side G Sensor Circuit .
Symptoms
- ABS, traction control and stability control warning lamps come on, usually all together
- Stability control is switched off, so the car no longer brakes individual wheels to correct a slide
- Hill-start assist, trailer stability aid and similar functions stop working
- Brief unwanted brake pulsing or stability intervention on a straight, dry road just before the system shuts down
- Live data shows a yaw or lateral G value frozen at one number, far from zero with the car parked, or dropping out
Likely causes
- Internal failure of the yaw rate and lateral acceleration sensor cluster
- Wet, corroded or loose connector at the sensor, which usually sits low in the centre tunnel or under a seat
- Open, chafed or shorted wiring between the sensor and the ABS / stability control module
- Sensor loose on its bracket, or refitted facing the wrong way after interior, airbag or suspension work
- Zero-point calibration never carried out after sensor, module, wheel alignment or suspension replacement
- Weak battery or a poor chassis ground pulling the sensor reference voltage down
- Data bus fault on the line that carries the sensor value, or a failed ABS / stability module
How to fix it
- Read every chassis code and the freeze frame first; a low system voltage code or a bus fault will set this one as a side effect
- With the car parked on level ground, watch live yaw rate and lateral G: both should sit near zero and move smoothly when the body is rocked
- Check the sensor mounting — it must be tight, flat on its bracket and oriented exactly as specified
- Unplug the connector and look for water, green corrosion, spread terminals and a locking tab that never clicked home
- Measure supply voltage and ground at the sensor with the ignition on, then check the signal or bus wires back to the module for opens and shorts
- Run the yaw / lateral G zero-point calibration with a capable scan tool after any repair, alignment or sensor swap
- Only when wiring, power and calibration all check out should the sensor assembly be replaced and recalibrated