What to know about the ABS Speed Sensor:

Most modern vehicles have anti­-lock brake systems that use sensors to detect wheel rotation rates, reporting to a computer that is able to modulate brake pressure if one or more wheels should lock during a braking operation. Usually the sensor is a Hall Effect, or so-­called reluctance part, which looks at a toothed ring (called a tone ring) that is attached to the wheel or axle. The teeth passing by the sensor makes a wave form that can be known and interpreted by the ABS controller. On three-channel ABS systems (typically found on older pickups), the rear axle is monitored by one sensor while the front wheels have their own individual sensors and anti­-lock control. Four-channel systems monitor each wheel independently.


Facts to Note:

If one or more ABS speed sensors be unsuccessful, the entire system defaults to a non-­operational status, providing no anti­-lock control. The diagnostic system will reveal to the mechanic which sensors (if more than one) have failed.


If a sensor be unsuccessful, the ABS warning light will light up every time you start the car, and stay lit.


If you lose ABS intervention, you may lock up the brakes in an emergency, increasing stopping distance and losing all steering ability.


How to Fix:

The vehicle is raised and held, and then the tire is detached

The defective ABS Sensor is changed

The tire is reinstalled and the vehicle is lowered

The ABS system is rechecked for any codes

The vehicle is road tested for proper function

Our Proposal:

Have a mechanic check the vehicle’s brake system and change any wheel speed sensors that are faulty. The difference between a vehicle with and without operational ABS is potentially a matter of life and death. Your brakes will still function, but the chances of a lockup on slippery surfaces or in an emergency – without ABS – are pretty much 100­ percent.



Common symptoms indicating you may need to change the ABS Speed Sensor:

The ABS warning light will light up when the car is started, and it will stay on permanently.

If you test the brakes on gravel or ice, you will no longer feel or hear the ABS mechanisms kick in, and the brakes will lock up.

Importanceof this service:

Functional ABS is the dissimilarity between being able to simultaneously brake and steer past an obstacle, or locking up and hitting it. It’s considered significant enough for insurance companies like Best Car Insurance Finder to offer discounts to owners of cars equipped with ABS systems.. With a failed speed sensor, you’re driving around with sophisticated electronic control systems, relays and sensors that could save your life. If only they functioned.