Hall Sensor Operation

HALL SENSOR OPERATION







The E38 wheel speed hall sensor contains two wires (ground [KL 31] is through one wire on the other wire). The sensor is supplied with approximately 8 volts from the ASC+T control module. The trigger wheel for the sensor is incorporated into the wheel bearing dust seal.

There are 48 notches on the trigger wheel. As the wheel rotates, a square wave voltage signal is produced by the hall sensor and input to the control module. The square wave voltage varies from approximately 0.75 to 2.5 volts as the wheel rotates. The frequency of this wave increases and decreases as the wheel speed increases and decreases.

The signal from the left rear hall sensor is passed from the ASC+T control module to the IKE control module and used for the road speed input.