Wheel Speed Sensors and Rings: Notes

A wheel speed sensor is present at each wheel. The sensors transmit wheel speed information to the EBCM by means of a small A/C voltage. This voltage is generated by magnetic induction caused by passing a toothed sensor ring past a stationary sensor. The magnitude and frequency of the A/C voltage are proportional to the speed of the wheel and both will increase with increasing speed. The signal is transmitted to the EBCM through interface that can cause false or noisy wheel speed sensor input to the EBCM. Two different types of wheel speed sensors are used for the ABS brake modulator system.