Brake Pedal Position (BPP) Switch
WARNING: This page is about a different car, the 2005 Ford RV Cutaway, 2005 Ford Econoline, 2005 Ford E450 Super Duty, and 2005 Ford Cutaway. 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 powertrain control module (PCM) that the brake pedal is applied. The PCM uses this input to disengage the converter clutch, speed control and auxiliary idle (if equipped).