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Many newer vehicles, and plenty of older ones, have an anti-lock braking system (ABS) installed by the factory. If your ABS system isn't working like it should, your issue could be as simple as replacing an ABS sensor.



What is an ABS Sensor?

For your ABS system to function properly, your vehicle needs to know the difference between locked wheels and rolling wheels. When your wheels are locked up under heavy braking, friction between the road surface and your tires decreases. Your ABS system uses a sensor to help modulate your brakes for maximum friction under heavy braking.

How does Your ABS Sensor Work?

ABS sensors send a signal to the ABS module when the wheels are locked up under heavy braking forces. When the module sees the correct signal, it releases a little bit of brake pressure to allow the wheels to continue rolling. The ABS then adds brake pressure until the wheels lock up again. You may feel this as feedback against your foot on the brake pedal, especially in slick conditions. Although your braking system is designed to stop your vehicle without a functioning ABS, the average driver brakes to a safe stop in less distance with functional ABS than without. You will find ABS sensors installed near all wheel hubs on vehicles equipped with ABS.

How are ABS Sensors Made?

Like every other sensor on your vehicle, ABS wheel speed sensors are made using heavy manufacturing equipment. It would be extremely difficult, if not impossible, to replicate an ABS wheel sensor using tools available to the average mechanic.

Why do ABS Sensors Fail?

  • Electrical components of all shapes, sizes, and functions are vulnerable to heat, moisture, and vibration.
  • Although ABS sensors, sometimes called wheel speed sensors, are designed to last for the life of your car, they do occasionally fail and need to be replaced.
  • It's far more common for an older vehicle with high mileage to require ABS sensor replacement.

What are the Symptoms of ABS Sensor Failure?

  • Your check engine light or ABS light on your vehicle’s dash may come on and stay on.
  • Your ABS may not function normally.

What are the Consequences of ABS Sensor Failure?

  • ABS failure increases emergency stopping distances up to 30%.
  • If not caught and repaired quickly, an ABS system failure at an inopportune time could result in a rear end collision or worse.

If you have questions or concerns about your ABS Sensor, or any of your vehicle's components, come into your local Pep Boys where we can answer any question, help you find any part, or perform any vehicle service you might need.