System Operation - Push Button Ignition Switch: Start

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.

When the START/STOP button is momentarily pressed and released when the ignition is off and the brake pedal is applied, the RFA module checks the vehicle for a valid programmed key as part of the PATS function. If it detects a valid programmed key, the RFA module sends a message to the BCM indicating a valid programmed key is detected. The BCM then provides power to the systems designed to operate when the ignition is in the RUN mode and allows the PCM to start the vehicle. Once the vehicle is running, the BCM provides power to the systems designed to operate when the ignition is in the ACC mode as well.

The ignition LED indicator illuminates when the ignition is in the RUN or START mode.

When the BCM changes the ignition mode, it communicates the ignition mode to the other modules by sending an ignition status message over the CAN.

The vehicle can be started from any ignition mode.