x12xe idle control question

[smoo]

On my x12xe equipped corsa b i thought the throttle was sticking, but when I looked the idle control valve was following the throttle so when the throttle is closed the ICV is a bit slow moving back hence the feeling the throttle was sticking. The cable and throttle move freely. So what I need to know is should the ICV being moving like this? My instinct is it should not as its an idle control, so another sensor is playing up. However the engine light has not come on.