2003 f150 imrc

We have a 2003 f150 with a 4.2 v6. Getting p1518 code bank 1 intake imrc stuck open. Ok I plan to remove the plenum but this is what I do not understand. We found both rods from the module fell out because of broken bushings. Ok we can move the valves connection by hand so they are not stuck. In either position the code remains. So how does the module work? How does if read the position of the valve if the rods are not connected?? Does the module itself have some way to measure position? Want to understand before doing the work.