Normal Operation
WARNING: This page is about a different car, the 2006 Ford Pickup, 2006 Ford F550 Super Duty, 2006 Ford F450 Super Duty, and 2006 Ford Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
The stoplamp switch sends a voltage signal through circuit 810 (RD/LG) to the powertrain control module (PCM) when the brake pedal is applied, and deactivates the speed control if engaged. The speed control deactivator switch sends a voltage signal through circuit 307 (BK/YE) to the PCM when the brake pedal is not applied. When the brake pedal is applied, the voltage signal is removed and the speed control is deactivated.