Many possibilities, but cleaning the IAC is a good place to start for an unstable idle. Be sure to put a rag or something below that area when removing the screws which are non magnetic stainless steel.
From the way it is worded, it sounds like the ICM and associated hardware is going to be changed, but it has not been done yet? If that is the case, doing so may fix multiple issues, especially if the original ICM shows signs of overheating.