Front

FRONT WHEEL SPEED SENSOR





DESCRIPTION
A wheel speed sensor is used at each wheel. The front sensors are mounted to the steering knuckles. Tone wheels are mounted to the outboard ends of the front axle shafts. The gear type tone wheel serves as the trigger mechanism for each sensor. The wheel speed sensor's function is to supply the current wheel speed to the CAB.

OPERATION
The wheel speed sensors convert the wheel speed into a digital signal. The CAB sends 12 volts to the wheel speed sensors. The wheel speed sensor has an internal magneto resistance bridge that alters the voltage and amperage of the signal circuit. This voltage and amperage is changed by magnetic induction when the toothed tone wheel passes by the wheel speed sensor head. This digital signal is sent to the CAB. The CAB measures the voltage and amperage of the digital signal for each wheel. The magnetic field of the wheel speed sensor is intersected by the teeth of a rotor. This changes the magnetic field and the coil induces an AC voltage. The frequency of this alternating current, governed by the number of teeth on the reluctor, fluctuates to reflect variations in wheel speed, is also proportional to wheel speed.