ABS sensor is a simple yet clever speed sensor and an integral part of your car's anti-lock braking system. It has a vital part to play in enabling you to steer smoothly and safely and to break without skidding or sliding. 

The ABS sensor is located, as you might imagine, positioned at the back of the wheel, close to the brake rotors.

This clever speed sensor monitors the speed at which each wheel is rotating and measures the amount of hydraulic pressure needed. This information is sent back to the ABS control unit which adjusts the brake pressure accordingly, stopping your car wheels from slipping and swerving. Essentially, the ABS sensor informs the anti-lock braking system that your wheels are about to lock, which in turn stops this from happening.

The ABS sensor can be prone to a build up of dirt over time, which can stop it from working properly. This can cause it to produce an irregular signal or no signal at all. Damage to the sensor's winding caused by constant vibration can also lead the ABS sensor to malfunction. Salt used on the roads in winter months can get into the sensors, which can damage the signal and prevent the sensor from working. If there is a fault with the ABS sensor , the ABS warning light will show on the display and the ABS system will stop working completely. If this happens you will still be able to break but it will be unassisted by the anti-lock breaking system.  Without the wheel speed sensors the anti-lock braking system cannot work. The Traction Control System (TCS) also uses the speed sensors so this will not work either if the sensors are broken. When this part fails, replacing it with a  ABS sensor will ensure you get a quality product that is right for the make and model of your car.