Brake Pressure Switch (BPS)
WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2018 Ford Transit-350 HD, 2018 Ford Transit-350, 2018 Ford Transit-250, 2018 Ford Transit-150, and 2018 Ford F-550 Super Duty. However, it is still accessible from the selected car via links, so may be relevant.
The BPS, integral to the brake pedal position (BPP) switch, is used for vehicle speed control deactivation. A normally closed switch supplies a ground signal to the PCM when the brake pedal is not applied. When the brake pedal is applied, the normally closed switch opens and the ground signal is removed from the PCM.
The normally closed BPS, along with the normally open BPP switch, are used for a brake rationality test within the PCM. The PCM misfire monitor profile learn function may be disabled if a brake switch concern occurs. If one or both brake pedal inputs to the PCM is not changing states as expected, a diagnostic trouble code (DTC) is set by the PCM strategy.