Wheel Speed Sensor: Description and Operation

Fig. 3 Wheel Speed Sensor:

Rotational speed of each wheel is detected separately by an inductive wheel speed sensor, Fig. 3. Electrical signal sensed from the speed sensors are transmitted to control module.
In this system, front wheels are controlled individually and rear wheels together. Control of rear wheels works on the ``Select Low'' principle. ``Select Low'' means wheel with the greatest tendency to lock-up (lower tire to road friction co-efficient), determines level of control.
Wheel speed sensors are installed in knuckles. Toothed rings are pressed onto front hub and bearing assemblies and rear drive shaft spindles. The wheel speed sensors do not require adjustment.