Stoplamp Switch
WARNING: This page is about a different car, the 2016 Ford Transit-350 HD, 2016 Ford Transit-350, 2016 Ford Transit-250, and 2016 Ford Transit-150. However, it is still accessible from the selected car via links, so may be relevant.
The stoplamp switch is a normally open switch and is provided voltage at all times. When the brake pedal is applied, the switch closes and routes voltage to the BCM.