No that’s not what happened.Sounds like he had a bad valve inside the iac and had to take it apart and shim the metal electrical part away from the aluminum part that bolts to the throttle body. Doing this solved his air leak through the iac. So now when the iac is commanded closed it actually stops the airflow and the idle drops to where it's supposed to be.
“Air leak inside the IAC”
I would ask anyone this, go to the auto store and ask for a IAC valve, blow air on one of the two holes on the valve body and I almost guarantee air goes thru the valve because it is open... It should be closed in my opinion, but that’s my personal opinion only.
Well, all I did was to retrieve the solenoid so the pintle just touches the valve’s sealing disc without voltage and from there the ECU takes over increasing the RPM on demand like when using the AC.
I think it makes perfect sense, and it’s working