Wheel Speed Sensor
WARNING: This page is about a different car, the 1999 Acura 3.0CL and 1999 Acura 2.3CL. However, it is still accessible from the selected car via links, so may be relevant.
Wheel speed sensors detect wheel rotational speed. Wheel speed sensor consists of a permanent magnet, coil and wheel pulser (trigger wheel). As wheel pulser rotates, magnetic field around coil in each wheel speed sensor fluctuates, generating voltage frequency signal proportional to wheel rotational speed. These pulses are sent to ABS control unit to determine wheel speed.