Deactivator Switch
WARNING: This page is about a different car, the 2004 Ford Focus. However, it is still accessible from the selected car via links, so may be relevant.
If the brake pedal is pressed rapidly while the speed control system is active, the speed control servo receives a input from the deactivator switch. This causes the electromagnetic actuated coupling to disconnect from the stepper motor and deactivate. This allows the cable and throttle to close under throttle return spring control. The system is put in stand by mode.