To Vent Open
WARNING: This page does not describe the selected car, but rather 7 other vehicles, including the 2002 GMC Yukon XL, 2002 GMC Yukon, 2002 Chevrolet Tahoe, 2002 Chevrolet Suburban, and 2002 Chevrolet Avalanche. 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, press and hold the sunroof switch forward. This will apply voltage through the sunroof switch close/tilt up contacts through the sunroof switch close signal circuit to the sunroof module. The sunroof switch close/tilt up input to the sunroof module needs to have constant voltage applied, switch pressed, to allow the motor to tilt the rear of the sunroof glass upward to the vent position.