With Intelligent Access (IA)
WARNING: This page is about a different car, the 2014 Lincoln MKX and 2014 Ford Edge. However, it is still accessible from the selected car via links, so may be relevant.
When the exterior liftgate switch is pressed, the Remote Function Actuator (RFA) module activates the power liftgate Intelligent Access (IA) feature. If the conditions allow, the RFA module sends a signal over the Medium Speed Controller Area Network (MS-CAN) to the LTM which opens the liftgate.