To Vent Open
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
To open the power sunroof to the vent position from the closed position, turn the ignition to RUN. Press and hold the sunroof switch forward. This will apply the sunroof switch low reference to the sunroof switch close signal circuit, 5 volt reference, pulling it to 0 volts. The sunroof switch close signal input to the sunroof control module needs to have constant 0 volts applied, switch pressed, to allow the sunroof control module to control the sunroof motor to tilt the rear of the glass upward to the full vent position.