Hi everyone
300E 1990

When I unplug the cable of ICV, I don't notice any change in rpm, however when I detach the ECU cable rpm changes. But with the ICV unpluged, detaching ECU cable doesn't have any effect. Moreover while opening the switch a soud like "click" can clearly be heard from the ICV. So I don't really understand whether it is working or not?
Any guidance is highly appreciated.