IAC position when driving along?

[Circlotron]

What happens to the IAC stepper when you are simply driving along? Does it close to minimum? Is there a setting in $12P for this parameter?

[The1]

usually it follows a throttle follower table.

[Circlotron]

Something like "Throttle crack offset vs rpm"?

[immortality]

I would have thought that it would be IAC- Motor Park Position V's Load table that is then modified by the others such as IAC - Max Throttle Follower Steps Vs RPM and IAC - Max Throttle Follower Steps Vs Vehicle Speed

Ahh, OK, you're using 12p. The tables might be named a bit different.

[festy]

Something like "Throttle crack offset vs rpm"?

That looks like it sets the IAC steps for a snapped-closed throttle vs RPM:

IAC_throttle_crack_vs_RPM.jpg (70.46 KiB) Viewed 3703 times

[VL400]

The throttle crack table is for decel conditions as festy mentioned, during decel (or any operating mode) if the MAP is below "Idle MAP Threshold Vs Idle RPM" then the throttle crack multiplier is used. This is a trap if you have a high vacuum engine, it can be triggered at idle which will drop out of closed loop control and add some IAC steps. Once MAP exceeds the threshold the throttle crack offset is used. Like most things IAC, they are all offsets added to the base IAC steps (the learnt steps from closed loop idle control).

The IAC gets some steps added to the base when leaving closed loop idle speed and is what you see when cruising along, this is extended throttle crack. Its a few steps to help the idle return to normal next time you enter closed loop control, its so when coming to a stop or after a rev the RPM drops to just above normal target and can smoothly be controlled to target.