Brake Pedal Position (BPP) Switch
WARNING: This page is about a different car, the 2005 Ford Pickup, 2005 Ford F550 Super Duty, 2005 Ford F450 Super Duty, and 2005 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Brake status comes from brake pedal position (BPP) switch. The BPP sensor supplies battery voltage to the PCM that the brake pedal is applied. The PCM uses this input to disengage the converter clutch, speed control, and auxiliary idle (if equipped).