Brake Pedal Position (BPP) Switch
WARNING: This page is about a different car, the 2008 Lincoln Navigator L and 2008 Lincoln Navigator. However, it is still accessible from the selected car via links, so may be relevant.
The brake pedal position (BPP) switch tells the TCM when the brakes are applied. The torque converter clutch disengages when the brakes are applied. The BPP switch closes when the brakes are applied and opens when they are released.