What does it mean?
C1104 is a Chassis (ABS, traction control, steering) fault code. It indicates: ABS LF Wheel Speed Sensor 1 .
Symptoms
- ABS and stability control warning lamps on, with normal brakes still working
- ABS engages at very low speed, for example as the vehicle rolls to a stop
- Traction control, hill start assist and cruise control disabled
- Speedometer reads erratically on vehicles that use this wheel for road speed
- The fault appears only over bumps or when the steering is on full lock
- Live data shows the left front wheel at zero or jumping while the others are steady
Likely causes
- Metal filings or brake dust collected on the sensor tip, narrowing the air gap
- Damaged, cracked or rusted tone ring with missing or corroded teeth
- Chafed or stretched sensor wiring where it follows the strut and steering knuckle
- Corroded or water filled sensor connector inside the wheel arch
- Excessive wheel bearing play changing the air gap as the wheel turns
- Internal sensor failure or a sensor pushed out of its bore
- Damage caused during a recent hub, brake or suspension repair
How to fix it
- Drive the vehicle with the scan tool showing all four wheel speeds and watch which one drops out
- Inspect the sensor tip and the tone ring for debris, rust and damaged teeth
- Check the harness along the strut and at the body grommet for chafing and stretched insulation
- Open the connector and look for water and green corrosion, then clean and reseal it
- Measure sensor resistance or output while turning the wheel by hand, comparing with the opposite side
- Check the wheel bearing for play and roughness
- Replace the sensor, tone ring or hub as required, then clear the codes and road test