Steering Wheel Switches
WARNING: This page is about a different car, the 2016 Ford Transit Connect. However, it is still accessible from the selected car via links, so may be relevant.
The cruise control steering wheel mounted switches are momentary contact switches. Each steering wheel switch function corresponds to a specific resistance value. The SASM sends out a 5-volt reference voltage to the steering wheel switch and monitors the voltage when a switch is pressed. The voltage varies depending upon the resistance of the specific switch pressed, indicating which switch is pressed.