Wheel Speed Sensor (WSS)

WSS are variable reluctance type. WSS is attached to steering knuckle on front wheels and on rear suspension knuckles on rear wheels, and consists of a sensor and a toothed sensor ring. See Figure and Figure. An AC voltage is generated when the toothed sensor ring passes by the sensor. The magnitude and frequency are proportional to the speed of the wheel, and both will increase with increasing speed. Air gap is not adjustable and sensor is not repairable. Front outside drive axle or rear hub and bearing assembly must be replaced if sensor ring is damaged.