What is a brake pad wear sensor and where is it located?

Some vehicles use an electronic sensor to warn you, the driver, when your brake pads are starting to get too worn down from the rigors of driving. This is called the brake pad wear sensor, also known as the brake pad wear indicator. The most common type of electronic wear sensors are mounted into the brake pad itself. On some applications the wear sensor is embedded into the pad and not removable; therefore they are only available with the brake pad. When the brake pad wears down to its discard thickness due to contacting the rotor while braking over the course of time, the sensor will make contact to the rotor, thus grounding the sensor. This will cause a brake warning light to illuminate on your dash or instrument cluster, indicating that the brake pad friction material is almost gone and that replacement brake pads are needed. This light usually looks like a circle, sometimes with an exclamation mark inside of it. 

Brake pad wear indicators are more prevalent on European models. They are usually found on the front brakes, but sometimes on the rear brakes as well. So, how many sensors a vehicle will have, and their location in terms of what wheels they can be found on will vary.

How do I know if my brake pad sensor needs to be replaced?

If your brake pad warning light comes on, then that means that your brake pad wear sensor has made contact with the rotor, and that means it needs to be replaced. Since a worn sensor coincides with worn brake pads, you may experience the squealing and poor braking associated with worn brake pads. Once the sensor has done its job, it’s no longer any good. Just think of the noble sacrifice it made to tell you that you need to change your brake pads. 

For this reason, you’ll need to replace the brake pad wear sensor at the same time that you replace the brake pads. Because of their small size, the brake pad wear sensor’s wires can also get broken during a brake job, so be careful when working around the sensor so that you don’t have to replace it twice. Also, the brake warning light can indicate a low brake fluid level, so be sure to check that the fluid level is not the source of your problem. 

Can I replace a brake pad wear indicator myself?

Replacing a brake pad wear sensor will add just one more step to any brake job you do. If you are comfortable working on disc brakes, then replacing the brake pad wear indicator will not prove difficult. Once you have access to the brake caliper, you’ll just have disconnect the old sensor from its wiring harness and disconnect it from the brake pad. Then just connect the new one and continue with your brake job. If, for some reason, you are only replacing the sensor, you’ll just have to remove the wheel to gain access to the brake caliper and the wear sensor. 

Need a brake pad wear sensor replacement?

Brake pad sensors provide a driver with a lot of benefits—including eliminating the need to visually inspect the pads every now and again to see if they are still in good shape. These sensors will let you know when replacements are needed, saving you time and effort. Also, by letting you know in advance when the brake pad material is almost gone and that you need to replace the pads, brake pad sensors can prevent extensive wear of the rotors, which occurs when the brake pad wears down to the metal and grinds against the metal rotor. So, making sure you replace your brake pad sensor(s) when necessary is important.

At 1A Auto, we make shopping for a brake pad wear sensor replacement for your car, truck, SUV or van easy - we're here to help you select the right part for your vehicle! Call our customer service toll free at 888-844-3393 if you have any questions about our brake pad wear indicators, warranty, compatibility or to purchase, or you can buy online.