Intake Manifold Change-Over Valve
WARNING: This page is about a different car, the 2002 Audi S4. However, it is still accessible from the selected car via links, so may be relevant.
Flaps in the multi-path intake manifold are opened and closed by the intake manifold change-over valve. Change-over valve is a vacuum servo electronically activated by the ECM.
To test intake manifold change-over valve, see intake manifold change-over valve related DTC(s) under DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article.