Variable Tuning 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.
During operation the control module applies ground to the variable tuning signal circuit which indicates to the microprocessor within the IMT valve to turn the motor ON which rotates the IMT valve within the intake manifold plenum.