Operation principle of the brake pad wear sensor
By applying pressure to the brake pads, a vehicle with disc brakes slows or stops the rotor attached to the wheel hub. When the brake pads wear down, a metal sheet will make contact with the rotor and produce a high-pitched squealing noise. However, if the brake pad wear sensors are mounted, this high-pitched squealing will not occur. If this is the case and the vehicle's brake pads are close to making contact with the rotor, a warning light will alert the driver that the brake pads need to be replaced. The sensors will wear out at the same time as the brake pad.
These electronic sensors serve as resistors that connect to a computer module. The sensors are mounted to the brake pad and are designed to maintain frictional contact with the brake rotor surface. The mounting interface utilizes a spring clip to hold the sensor in place with a retention force greater than 30 newtons. A vehicle needs to be equipped with two brake pad wear sensors (one in the front axle and one for the rear), as well as software and algorithms to accurately monitor brake pad wear.