What it means
Wheel speed sensors disagree on rotation direction — typically detected when reversing. Wheel-speed signals feed ABS, ESC, traction control, transmission and odometer — a single dropped signal disables all of these safety functions until repaired.
At a glance
- Usually lights the ABS or stability-control warning light
- The engine or gearbox may go into limp mode
How it works
The ABS module compares wheel-speed signals to determine whether the wheels are turning forward or backward. This code sets when the reported rotation directions do not agree, often during reversing, and may result from a sensor fitted on the wrong side, reversed wiring polarity, an incompatible target, or signal interference.
Common causes
Most likely first.
- Wheel speed sensor installed on the wrong side
- Sensor wiring polarity reversed
- Incorrect sensor or tone wheel
- Wheel speed signal interference
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Review ABS freeze-frame data and live wheel-speed direction readings, noting whether the mismatch occurs while reversing or at a particular wheel.
- Confirm each wheel-speed sensor is installed at its specified wheel and that any recent sensor or hub replacement used the correct application.
- Inspect the sensor connectors and wiring for repairs, swapped terminals, pin damage, or routing near sources of electrical interference.
- Check the wheel-speed targets for the correct type, orientation, damage, and cleanliness at the wheels implicated by live data.
- If the installation and wiring look correct, compare sensor signals using the manufacturer's test procedure to locate interference or an internal ABS-module issue.
Common fixes
- Reinstall a sensor on its specified side if it was fitted in the wrong position.
- Correct reversed or mispinned sensor wiring.
- Fit the correct sensor or wheel-speed target for the vehicle.
- Repair damaged wiring or reroute it away from an identified interference source.
- Repair or replace the ABS module only if testing confirms it misreads valid signals.
Can I keep driving?
ABS, stability control, or traction control may be disabled, and speed readings may become erratic. Drive cautiously and avoid reversing or driving on slippery surfaces more than necessary until the direction mismatch is corrected.
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.