The ABS Speed Sensor is a critical component of the Anti-lock braking system. The ABS Speed Sensor sends out electrical pulses through magnetic induction which suppies information about wheel speed to the ABS computer.

Under braking, if wheel speeds are not equal, indicating wheel lockup, the computer modulates the anti-lock feature until the speeds are equal again.This is the pulse you feel in the pedal when the Anti-lock system is engaged. If your vehicles ABS Speed Sensor is not fuctioning properly, it will send incorrect information to the ABS computer and may cause your Anti-lock Braking system to fail.

ABS Speed Sensors are usually located near each wheel hub on disc systems and on drum systems, they are often mounted on the differential housing. The ABS Speed Sensor can either be "exposed" or concealed". Exposed sensors should be inspected on a regular basis. A good rule of thumb is to inpect the sensors each time the brake pads are replaced.