Severity: Moderate
Drivable, but it can cause more damage or poor economy. Get it checked within days.
What C0040 means
The ABS module sees a problem with the right front wheel speed sensor. ABS and stability control are usually disabled.
Symptoms
- ABS, traction and stability lights on
- Speedometer erratic on some vehicles
Common causes
Most likely first
- 1Damaged sensor or wiring at the wheel
- 2Rust or debris on the tone ring
- 3Excess wheel bearing play
How we diagnose it
- Compare all four wheel speeds while driving
- Inspect wiring and tone ring
- Check bearing play
Every vehicle sets codes under its own conditions. We check the factory diagnostic steps and service bulletins for your VIN, so the repair targets the actual cause.