Circuit Operation

As each wheel turns, the wheel speed sensor for that wheel creates a small AC voltage as a toothed sensor ring, mounted in the front integral hub/bearing assembly, is passed by the stationary sensor. The sensor consists of a permanent magnet and coil and generates voltage by magnetic induction. The frequency of the wheel speed sensor signal is proportional to wheel speed.

The EBCM uses the wheel speed sensor signal to calculate vehicle reference speeds and individual speed, acceleration and slip values for each wheel. These values are used to determine when anti-lock control is required. See Figure .