Full Open Switch: Operation
WARNING: This page is about a different car, the 2006 Dodge Grand Caravan, 2006 Dodge Caravan, and 2006 Chrysler Town & Country. However, it is still accessible from the selected car via links, so may be relevant.
When the power liftgate reaches the full open position, the gear motor housing mounted full open switch electrical contacts close. This sends a ground signal to the power liftgate control module, telling the module that the liftgate has reached the full open position.