Brake pad wear sensors are designed to warn drivers the pads are coming to the end of their service life. Brake pad wear sensors plug into the vehicle's electronics to illuminate the dashboard warning light when the pads are worn. Sensors should be changed when installing new pads. Contains 1 Bendix brake wear sensor Brake Wear Sensor BWS1091 Brake pad wear sensors are designed to warn drivers the pads are coming to the end of their service life. The sensors plug into the vehicle's electronics to illuminate the dashboard warning light when the pads are worn. It is recommended to change sensors when installing new pads.