Theory Of Operation
WARNING: This page is about a different car, the 2015 Fiat 500. However, it is still accessible from the selected car via links, so may be relevant.
The Liftgate is controlled as a third door, so when the doors are locked the Liftgate is also locked, and when the doors are unlocked the Liftgate is unlocked as well. When the Liftgate is unlocked, it can be opened by means of the button on the external handle. If the trunk is mechanically opened, it's logic state does not change, and when closed again it automatically aligns with the status of the other doors (Locked/Unlocked). The Liftgate cannot be opened with vehicle speed over 13 mph, to prevent accidental Liftgate opening.