IAC-AAC Location? Anybody?

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jmercjr
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IAC-AAC Location? Anybody?

Postby jmercjr » Tue Mar 26, 2013 4:19 pm

I have a 1999 Pathfinder! I have the P505 code and everyone seems to suggest cleaning the IAC valve. Trouble is nobody has a definitive location for this valve. Some say on the manifold near the throttle body? Heck if I can find mine. I even removed the throttle body to look for it! I would appreciate any help! Also, I was told there is a recalibration procedure using the OBDII for this valve. Any info on this would be helpful too! Thanks....


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smj999smj
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Postby smj999smj » Tue Mar 26, 2013 11:39 pm

It's actually an "IACV-AAC Valve" and it's bolted to the underside of the upper intake plenum, which is why it's so hard to find. Stand on the left, or driver's side of the engine compartment. Look toward the rear side of the upper intake plenum and you should be able to see the IACV-AAC valve sitting on the bottom side of the plenum. You should see a Phillips type adjustment screw if you look carefully; this is used to adjust the base idle. If you see this adjustment screw, then you are looking at the IACV-AAC valve. Don't ask me how you are going to clean it without removing the upper plenum!

jmercjr
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Postby jmercjr » Wed Mar 27, 2013 1:37 am

Thanks I will look again! I have been all over that plenum but have not seen it yet. I was/am hoping not to remove the plenum. An idle adjustment may be all I need. It does not want to idle on cold starts and is idling a little low during normal operation.

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smj999smj
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Postby smj999smj » Wed Mar 27, 2013 8:15 pm

In order for the IACV-AAC valve to work correctly, the base idle has to be adjusted properly. This usually involves warming up the engine to normal operating temperature (2000RPM for 2 minutes), shutting the vehicle off, unplug the TPS, restart and rev the engine a couple of times, let the idle settle and adjust the base idle by turning the idle screw on the IACV-AAC valve (clockwise to lower, counterclockwise to raise RPM). Then, shut the vehicle off, plug in the TPS and restart. If it hasn't been done lately, I recommend cleaning the inside of the throttle body and throttle plate first and taking for a short drive before doing the adjustment procedure.


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