Anti-Lock Braking Sensors (ABS Sensors)

What Does The ABS Sensor Do?

The ABS sensor measures the wheel speed and direction of wheel rotation, this information is then relayed to the ECU which uses it to prevent the brakes from locking under severe braking conditions. If the ECU senses that a wheel has locked, it will release the brake pressure from the wheel – as soon as the wheel is rotating freely again, it will reapply the brake pressure.

Where is The ABS Sensor Located?

The ABS sensor is located behind the wheel, close to the brake pads. For easy access to most ABS sensors, remove the wheel and then turn the steering in the opposite direction to the side of the vehicle you are accessing (for example, if you are working on the drivers’ side, turn the steering wheel all the way towards the passenger side).

What Are The Failure Symptoms Of The ABS Sensor?

Failure of the ABS sensor is most commonly indicated by the ABS warning light illuminating on the vehicles dashboard. Another symptom is finding the vehicles wheels locking under heavy braking.

Maintenance Of The ABS Sensor

ABS sensor failure can often be caused by build-up of grime and dirt on the sensor. It is recommended that the sensor is checked regularly (at service intervals, or when brake pads are being changed). Any build-up of dirt should be wiped away – it is also important to check the sensor itself and the sensor terminals for any corrosion or damage.

What Else is The ABS Sensor Commonly Called?

The ABS sensor is also commonly referred to as an Anti-Lock Braking Sensor, a Wheel Speed Sensor (WSS) or Vehicle Speed Sensor (VSS).