The middle one is +12v, one side opens, the other side shuts.
If its using the 20V config I did, then I have Dual Solenoid option enabled - this uses the two FETs adjacent to each other to flutter the IACV open and shut.
You could Disable the Dual Solenoid option Extras->Idle Settings General and select the FET channel that closes the IACV
then you'll have a range of control from the max RPM that you have with the IACV disconnected to when it is fully closed.