Circuit Description

As a toothed ring passes by the Wheel Speed Sensor (WSS), changes in the electromagnetic field cause the wheel speed sensor to produce an AC voltage signal. Voltage signal frequency and amplitude are proportional to wheel speed. The magnitude of this signal is directly related to wheel speed and proximity of wheel speed sensor to toothed ring, often referred to as the air gap.

Conditions for setting DTC:

• Left front wheel speed is less than 4 MPH.
• All other wheel speeds are greater than 8 MPH.
• No unexpected wheel acceleration/deceleration. Anything that keeps the left front wheel speed sensor signal low while vehicle is moving at greater than 8 MPH.