Car idles high- 2k+rpm- pulled some codes

[SN95StangMan]

hey guys. My car is giving me a problem and im trying to figure it out. it just started idling high all of a sudden. When my car is in park, it will idle at or around 2k rpm. if i drop in in (R)everse, it the idle will drop to around 1200, which is still high. in (D)rive it will still be around 1200 rpm. I pulled some codes with a paper clip and this is what i got

411- unable to control rpm during low rpm self test
412- unable to control rpm during high rpm self test
532- cluster control assembly CCA circuit failure
536- Brake On/Off BOO circuit failure /not activated during the koer
538- Insufficient change in RPM/ operator error in dynamic response check

**These were all during koer, i didnt get anything koeo

I know how to pull the codes, but i dont know what the hell to do next. can you guys help me diagnose this problem. Ill pull the codes again tomorrow morninig. Thanks

 

[HISSIN50]

Did you tap the brake pedal while running the codes? If not, that can be the BOO code.

The first two are very likely relating to the IAC. I'd clean it and reset the KAM and see what it does.

Good luck.

 

[SN95StangMan]

i cleaned the iac and no luck. i have another iac in the garage on the stock tb, ill try putting that one on tomorrow. hopefully that will help. thanks for the input.

 

[SN95StangMan]

** when the car was running, i unplugged the iac and nothing hapenned. would that mean that the iac is good/bad??

 

[HISSIN50]

** when the car was running, i unplugged the iac and nothing hapenned. would that mean that the iac is good/bad??

It totally depends upon how you set your idle and when you test it. E.g., I set my hot, no load idle so the IAC has under 5% duty cycle. I can unplug it and it makes no difference. But if my car is cold, you bet that unpluggin the IAC would make a difference. As would having AC on.

Given the idle settings you're seeing, either there's a good sized vac leak and the IAC is at 0% duty cycle (it cant go negative so unplugging it makes no difference) or the IAC itself is jacked.

It seems to me that the IAC is working to an extent because you see a differential between a cold and hot motor in terms of idle speed. If you turn the AC on, does the idle go up a little? If so, the IAC would seem to be functional to some degree.

A stockish motor should pull 16-20" hg at idle (I forgot to check your sig).

Good luck.