What it means
Left Rear Wheel Speed Sensor B 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 left rear wheel speed sensor B must be the type and electrical design the ABS control module expects to read. This code sets when the installed component or its connection does not match that expected configuration, so the module cannot interpret the left rear wheel-speed signal correctly.
Common causes
Most likely first.
- Incorrect replacement wheel speed sensor
- Wrong sensor type or electrical specification
- Sensor not fully seated or installed in the correct position
- Connector or wiring mismatch
Symptoms
- ABS warning light on
- ESC/stability control deactivated
- Possible reduced brake assist
- Speedometer may behave erratically
How to diagnose it
- Review freeze-frame data and live wheel-speed readings to confirm that the left rear sensor B signal is missing or implausible after a repair.
- Check the left rear service history and verify that the installed sensor is specified for this vehicle and position.
- Inspect sensor B seating and mounting to confirm it is in the correct position and fully installed.
- Compare the connector keying and wiring arrangement with the vehicle's specified sensor configuration.
- If the correct part and installation are confirmed, test the wiring and ABS module input using the manufacturer's procedure.
Common fixes
- Install the specified left rear wheel speed sensor B if the wrong type was fitted.
- Correctly seat and secure the sensor in its intended mounting position.
- Repair any connector or wiring mismatch using the vehicle's specified configuration.
- Repair the ABS module circuit only if testing confirms a fault after the correct sensor is installed.
Can I keep driving?
Basic braking may remain, but ABS and stability or traction control may be unavailable and the speedometer may behave erratically. Drive cautiously and avoid relying on those systems until the correct sensor and connection are in place.
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.