Brake Pedal Position (BPP) Switch
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2016 Ford Transit-350 HD, 2016 Ford Transit-350, 2016 Ford Transit-250, 2016 Ford Transit-150, and 2016 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The BPP switch provides a signal to the PCM indicating the brakes are applied. The BPP switch is normally open and mounted on the brake pedal support. The BPP switch is hardwired to the PCM supplying battery positive (B+) voltage when the brake pedal is applied.