Wheel speed detection

 

In contrast to the previous versions, the speed signals are supplied by four "active" speed sensors.

The ABS control unit supplies the voltage to the speed sensors (7.6...8.4 V direct voltage) as from ignition lock position 2.

The speed signals are square-wave signals with constant amplitude (low level = 0.75 V, high level = 2.5 V). The frequency is dependent on the wheel speeds and is within the range from 0 to 1700 Hz (0 to 250 km/h).