Window Express Down Feature
WARNING: This page is about a different car, the 2010 Saturn Sky and 2010 Pontiac Solstice. However, it is still accessible from the selected car via links, so may be relevant.
The driver door window is equipped with the Express Down feature. This feature allows the driver door window to be fully opened by momentarily pressing the window switch to the second detente of the Down position. When the switch is operated to Express Down, both the Down contacts and the Express contacts of the switch are closed to ground and the signal is interpreted as an Express Down request.