What it means
Left Front 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 ABS module expects a particular type of left front wheel speed sensor B and checks whether the installed component produces a compatible signal. This code sets when the module identifies an incompatible sensor or installation, including a sensor with the wrong electrical type or connector arrangement.
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
- Check ABS freeze-frame data and live wheel-speed readings to confirm the left front B fault and note whether the sensor was recently replaced.
- Read the sensor identification and compare its application and electrical type with the vehicle's required specification.
- Inspect the left front sensor B connector and harness for a mismatch, adapter, altered wiring, or terminals that do not match the vehicle connector.
- Check that sensor B is fully seated in its intended position and that the mounting surface and sensor gap meet the manufacturer's specification.
- If the installed part and fit are correct, test the sensor B circuit and signal using the manufacturer's procedure before considering an ABS module fault.
Common fixes
- Reseat the left front sensor B correctly and secure its connector.
- Repair a connector or wiring mismatch using the correct terminals and routing.
- Replace the sensor with the correct type for the vehicle's left front B position.
- Correct sensor mounting or gap to the manufacturer's specification.
Can I keep driving?
Keep speed and braking gentle because ABS and stability or traction control may be unavailable. Avoid poor-traction conditions until the correct sensor is installed and the warning is resolved.
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.