What is "Asymmetric PID Conf"

[wazzu70]

What does this setting enable on the "Idle Control PID Settings" dialog?

[fphil]

On my wiki page http://www.vems.hu/wiki/index.php?page=MembersPage%2FFPhil%2FInjection
I got the following answer
"- I have not understood what the option "Asymmetric PID conf" does.
   .. if enabled, bigger (twice) values to feed more air (push RPM up) than to remove air."

Last week I started to use the I term of the idle control, but I have not understood how the I action works when the increase and decrease limits are set opened.  I may report on my page.

As said elsewhere better to open only the decrease limit and to choose the IAC DC reference for an idle rpm well above the rpm idle target. In this case the integrator term starts to add up (for decreasing IACDC) when the rpm first crosses from under to above  the rpm idle target.
If the rpm happens to become lower than the target then the integral term decreases (for increasing IACDC). I did not notice  in this case (rpm<target) the integration is done twice  faster when the  "Asymmetric PID control" option is enabled.

Beware each limitation (on 1 byte) is done without the integration constant which is multiplied afterwards, which means that the actual limit for the action on the IACDC value depends on this integration factor.
Sometimes I feel it could be easier to have the fw code to read.

[wazzu70]

Thank you! I had no idea what that feature did as it was not in the help dialog.

I agree, sometimes just reading the code is easier to understand what is going on. Its not available for obvious reasons now though.

[UrSobsessed]

Enabling "Asymetric PID Control" helped keep my car from stalling when running the a/c when really hot out.  I had stalling issues before I enabled it.  After enabling, none.  I have read that it can cause a bit of a rolling idle when enabled, but I don't see any of that on my set up.