Brake Pad Wear Indicator Light
Electronic sensors provide a warning light for the driver when the brake pads have worn past a specified limit. They replace an audible metal clip that's fastened to the brake pad. When the pad wears down to the clip, a loud squeal is heard when the brakes are applied.
The electric pad warning system is a less intrusive way of indicating pad wear to the driver. When this wired circuit is interrupted, the pad wear warning light will activate on the instrument panel.
Unfortunately, by the time the drivers light comes on, the sensor's circuit has already been broken requiring sensor replacement. Test these sensors for resistance with an ohmmeter.