Really high idle

[max]

Thanks for the tip Henrik, as you would have read; on every startup the ecu does not know at which position the iacv is, so it "resets" the iacv fully open and then steps it back the amount required to idle the engine at the temperature it is at that time.

You can experience this when you start the engine when this cycle is still in progress and the engine revs higher before settling down at the appropriate rev's for it's temperature.

If you have the diagnostic tool you can also observe the position of the iacv, the program indicates the position as a number in the data list and you can see it change for every "step" as the ecu adjusts it's position.

It also moves when you operate the throttle from closed as some type of "takeoff assist".