Toothed Ring

Wheel sensors/pulse wheel





The control module gets continuous information on wheel speed from the front and rear wheel sensors which count the teeth on the pulse wheel inductively. The back wheels use the average of the wheel movements, as there is only one sensor and pulse wheel here, the latter being housed in the differential casing.
The wheel sensors use pulse wheels with 48 teeth. Each time a tooth passes the sensors, it induces a current which is sent to the control module. By comparing the signals from the different sensors, the control module can tell whether any wheel is threatening to lock during braking.