What it means
This code identifies a fault associated with a rear tone wheel used by the wheel-speed sensing system. The code does not specify a single-sensor solid-axle layout or establish the specific cause.
How it works
The rear tone wheel is the toothed or encoded target whose movement lets a wheel-speed sensor report wheel rotation to the ABS module. This code points to a fault associated with that rear target, but it does not identify which rear layout or a specific physical defect.
Common causes
Most likely first.
- Damaged or cracked tone wheel
- Rust or debris on the tone wheel
- Tone wheel loose or misaligned
- Incorrect sensor air gap
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Read ABS codes and freeze-frame data, then compare live rear wheel-speed readings at low speed for dropouts or disagreement.
- Inspect the rear tone wheel or encoded target identified by the vehicle service information for cracks, missing features, rust, debris, looseness, or misalignment.
- Check the corresponding rear sensor mounting and air gap for damage or contamination that could prevent it reading the target correctly.
- Rotate the affected wheel by hand with the vehicle safely supported and observe whether the target runs true and the sensor signal remains consistent.
- If the target and gap appear sound, inspect the sensor wiring and connector, then use the manufacturer's tests to separate a target fault from a sensor or circuit fault.
Common fixes
- Remove rust or debris from the rear tone wheel and sensor area.
- Correct a loose or misaligned tone wheel.
- Repair the sensor mounting or air gap if the vehicle design allows adjustment.
- Replace a cracked or damaged rear tone wheel.
Can I keep driving?
The brakes still work, but ABS and stability control may be disabled or unreliable. Drive gently, especially on wet or loose surfaces, and avoid relying on those systems until the rear signal is restored.
A code shows where the control module detected a fault, not always which part failed. Check the causes in order and confirm with a test before replacing parts. Have several codes? Check them together
This is a generic code: it means the same on every make. The car’s maker may add more detail in its own service information.