What it means
This code identifies a subfault associated with a rear wheel-speed sensor. The base code does not specify the electrical or signal failure; consult the failure subtype and vehicle diagnostics.
How it works
A rear wheel-speed sensor reports wheel rotation to the ABS module, which uses that information for anti-lock braking and stability functions. This code identifies a rear sensor subfault, but the base code does not distinguish an electrical problem from a weak or implausible signal.
Common causes
Most likely first.
- Wheel speed sensor failure
- Damaged or corroded sensor wiring
- Loose or contaminated connector
- Excessive sensor air gap
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Scan the ABS module and review freeze-frame data, then compare live rear wheel-speed readings to find whether one rear signal is missing or erratic.
- Inspect the rear sensor, its mounting, connector, and harness for impact damage, corrosion, contamination, or a stretched wire.
- Check that the sensor is seated correctly and that its gap to the target is within the manufacturer's specification.
- Inspect the rear tone wheel or encoder for damage, debris, rust, or runout that could interrupt the sensor signal.
- If visual checks do not identify the fault, test the rear sensor and circuit using the vehicle wiring diagram and manufacturer's procedure.
Common fixes
- Clean contamination from the rear sensor and target.
- Reconnect or repair a corroded or damaged rear sensor connector.
- Repair chafed or broken sensor wiring.
- Correct sensor mounting or air gap where serviceable.
- Replace the rear wheel-speed sensor if testing confirms it has failed.
Can I keep driving?
ABS and stability control may be limited or disabled, although conventional braking may remain available. Leave extra distance and drive cautiously, particularly in poor traction, until the rear sensor fault is fixed.
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.