Wheel Speed Sensor: Description and Operation

There is a wheel speed sensor located at each of the four wheels and each is individually connected to the ABS Control Unit. Each sensor contains an electrical coil and a magnetic structure, and each is located in close proximity to a rotating toothed sensor rotor. When a tooth on the rotor passes by the sensor, a voltage pulse is induced in the sensor's coil. The ABS Control Unit counts these pulses to determine wheel speed.