V90 L6-2.9L VIN 96 B6304S (1998)
Wheel Speed Sensor: Description and Operation
Wheel Sensors/Pulse Wheel
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.