IMT Fan Position Signal Circuit
WARNING: This page is about a different car, the 2006 Pontiac Montana SV6, 2006 Chevrolet Uplander, and 2006 Buick Terraza. However, it is still accessible from the selected car via links, so may be relevant.
When the IMT valve is rotated the hall-effect switch detects the movement and provides a signal to the micro-processor which provides a feedback signal to the control module. The control module uses this feedback signal to determine the position of the IMT valve.