Wheel Speed Sensor: Description and Operation

Wheel Speed Sensor
It consists of a sensor and a rotor. The sensor is attached to the knuckle on the front wheels and to the rear axle case on the rear differential.
The front sensor rotor is attached to the each brake rotor by bolts.
The rear rotor is press-fit in the differential case.
The magnetic flux generated from electrodes magnetized by a magnet in the sensor varies due to rotation of the rotor, and the electromagnetic induction generates alternating voltage in the coil. This voltage draws a "sine curve" with the frequency proportional to rotor speed and it allows detection of wheel speed.