What it means
Right Rear Wheel Speed Sensor A Incorrect Component Installed: the installed component does not match the type the vehicle expects. Wheel-speed signals feed ABS, ESC, traction control and the speedometer.
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 right rear wheel speed sensor A reads the rotating wheel or its tone ring so the ABS and stability systems can track that wheel’s speed. The control module compares the sensor signal with what it expects from the installed sensor and tone-ring combination; it sets this code when the component type appears incompatible.
Common causes
Most likely first.
- Incorrect right rear wheel speed sensor installed
- Incorrect or mismatched tone ring
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Use a scan tool to record freeze-frame data and compare live right rear wheel speed with the other wheels at low speed, looking for a missing or implausible signal.
- Check the right rear sensor’s part identification and fitment against the vehicle’s required component type.
- Inspect the right rear tone ring for a mismatched type, damage, contamination, or incorrect installation.
- Inspect the right rear sensor connector and wiring for looseness, corrosion, damage, or routing that could disturb the signal.
- If the parts and wiring appear correct, test the right rear sensor signal and tone-ring pattern using the manufacturer’s procedure.
Common fixes
- Install the correct right rear wheel speed sensor.
- Fit the correct tone ring if it is mismatched or damaged.
- Repair or secure the right rear sensor connector or wiring.
- Clear the code and verify that right rear wheel-speed data tracks the other wheels.
Can I keep driving?
Basic braking may remain available, but ABS and stability control can be disabled, and the speedometer may behave erratically. Drive cautiously, allow extra stopping distance, and avoid slippery roads until the right rear signal is reliable.
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.