Wheel speed sensor
The vehicle speed is detected by the hall IC type wheel speed sensor (1) and encoder (4). The wheel speed sensor is fixed to the knuckle and includes a hall IC (3) having 2 hall elements (2).
The encoder consisting of a permanent magnet which has S/N electrodes turns inside of the wheel hub along with the wheel. The wheel speed sensor outputs alternate current.
As the cycle of the alternate current is in proportion to the revolution speed of the encoder, this AC signal (5) is converted into the voltage signal in the ESP® control module (6) for detection of the wheel speed.