The ABS speed sensor is attached to the wheels or axle on your vehicle and its main job is to measure the wheel rotations. In turn, it relays that information to your vehicle’s computer where the computer will determine whether or not the ABS is needed.
The ABS (anti-lock braking system) on the newer cars and most of the older models still on the road, keeps you from skidding when braking on a wet surface. It is designed to keep continuous traction on the road surface to prevent a brake lock-up.
If the speed sensor is bad or there is a hub problem, your brakes may not operate properly, which can cause you to skid or lose control of your vehicle.
Warning Light
The first indication that there is something wrong with your ABS brakes is the warning light on the dashboard. While the light does not tell you which part is a problem, if you have any of the other symptoms of a failing speed sensor, you might want to check there first.
Loss of Traction
When driving on icy or wet surfaces, your ABS should keep your vehicle in contact with the road and lessen traction loss. If you feel the car losing traction in those circumstances, there could be a sensor problem. You might notice it most when you accelerate or stop. While it could also be a module problem with the ABS system, the sensors are usually the culprit.
Brakes Take Too Long
If you notice that you are taking a long time to stop, your ABS speed sensor may be failing. The sensor should tell the brakes to activate whenever there is a heavy braking situation, but if you find yourself skidding, there could be a problem with the sensors. Since the ABS system is designed to maintain traction at all times, a loss of traction can be a good indication there is a problem.
If you notice the brake pedal pulsating, that can be another sign that there is a problem with the speed sensors.
Losing traction while braking, especially in heavy braking situations, can cause you to lose control of your vehicle. Any issues with your brakes should be checked as soon as you notice them; even if it is just the ABS light. If you do not know how to do this yourself, then bring it to a professional technician who is trained in diagnosing ABS problems.