What does it mean?
C1115 is a Chassis (ABS, traction control, steering) fault code. It indicates: ABS Wheel Speed Sensor Signal Abnormal .
Symptoms
- ABS and stability control warning lamps illuminated
- Live data shows one wheel dropping out or jumping while the others track smoothly
- ABS activates unexpectedly at low speed or on a good surface
- Stability control cuts in during normal cornering
- Speedometer flickers on vehicles that derive speed from a wheel sensor
- Fault appears only at certain speeds or after driving over rough roads
Likely causes
- Debris, brake dust or metal particles collected on a sensor tip
- Cracked, rusted or displaced tone ring with damaged teeth
- Mismatched tyre sizes, uneven wear or a space saver spare fitted on one corner
- Chafed or stretched sensor wiring at the wheel arch or the suspension pivot
- Corroded sensor connector allowing signal noise
- Excessive wheel bearing play varying the air gap while driving
- Interference from an aftermarket accessory routed near the sensor wiring
How to fix it
- Record all four wheel speeds during a road test and identify which one misbehaves
- Check tyre sizes, pressures and tread depth across the axles
- Inspect the sensor tips and tone rings for debris, rust and damaged teeth
- Follow the sensor harnesses for chafing, stretch and hardened insulation
- Measure sensor resistance or output and compare left to right
- Check wheel bearings for play and roughness
- Replace the faulty sensor, tone ring or bearing, then clear the code and confirm with a road test