Ignition Switch - Push Button
WARNING: This page is about a different car, the 2016 Ford Expedition. However, it is still accessible from the selected car via links, so may be relevant.
The push button ignition switch is a momentary dual contact switch that provides direct input to the BCM, the RFA module and the PCM. Both sets of contacts are normally open. When the START/STOP button is pressed, one set of contacts provides a ground signal to the BCM and the other set of contacts supplies voltage to the BCM, the RFA module and the PCM.
The ignition mode LED indicator is located near the top of the START/STOP button and is controlled by the BCM.