What it means
Right Front Wheel Speed Sensor B Range/Performance: the signal is implausible or outside the valid range. 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
Right front wheel speed sensor B supplies wheel-rotation information to the ABS module. This code sets when its signal falls outside the valid operating range or behaves implausibly, which can happen if the encoder is damaged, the sensor is weak, or its mounting dampens the signal.
Common causes
Most likely first.
- Tone ring damaged or contaminated
- Sensor element aged beyond calibration window
- Sensor mounting loose - signal damping
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Save the ABS freeze-frame data and compare right front sensor B live speed with the other wheels during slow straight-line movement.
- Inspect the right front tone ring or encoder for damage or contamination that could produce an irregular pulse pattern.
- Check that sensor B is firmly mounted and seated, and measure its gap against the manufacturer's specification.
- Inspect the sensor B wiring and connector for damage or looseness that could distort the signal.
- If the encoder, mounting, and wiring pass, test sensor B output across wheel rotation and compare it with the manufacturer's specification.
Common fixes
- Remove contamination from the right front encoder if it is intact.
- Secure or correctly seat the right front sensor B and set its gap to the manufacturer's specification.
- Repair damaged wiring or connector contact affecting sensor B.
- Replace a damaged encoder or a sensor B that fails its output test.
Can I keep driving?
Use caution because ABS and stability or traction control may be disabled, especially during sudden stops or on wet or loose surfaces. Keep speeds low and arrange diagnosis before relying on those systems.
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.