9-5 Aero (9600) L4-2.3L Turbo (2.3HOT) (2004)
Wheel Speed Sensor: Description and Operation
ABS Without TCS or ESP
Front Wheel Sensors
Front-wheel sensors
The front left wheel sensor sends a wheel-speed signal to pin 7 on the control module. The sensor is grounded via pin 6.
The front right wheel sensor sends a wheel-speed signal to pin 5 on the control module. The sensor is grounded via pin 3.
The sensor unit has a toothed wheel with 29 teeth and an inductive sensor.
The inductive sensor works like a small alternator, the sine-wave voltage of which increases with increasing wheel speed. The sine-wave voltage
alternates between positive and negative polarity, which is achieved by alternate teeth and gaps on the toothed wheel. The control module uses this
change of polarity as a pulse sensor. The frequency of the pulses increases with the speed of the wheel.
With a multimeter set for AC voltage connected between the two leads of the sensor, a reading of 100 mVAC should be obtained when the wheel is
rotated one revolution per second.
A wheel speed of 20 km/h gives about 5 VAC.