Vacuum System
WARNING: This page is about a different car, the 2001 Mercedes-Benz SL500 and 2000 Mercedes-Benz SL500. However, it is still accessible from the selected car via links, so may be relevant.
Vacuum elements for center and side outlets contain feedback potentiometers. Feedback potentiometers indicate to control unit the current position of flaps. When no vacuum is applied, side air outlets are open and center air outlets are closed. Vacuum elements are controlled by switchover valve unit. Switchover valve unit controls air flap vacuum elements.