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2001 Pontiac Aztek 3.4.
The IAC is raising rpms even though the computer shows it's requesting a lower rpm.
This only occurs when cooling fans kick on at 223 degrees.
I have a Modis but still learning.
Help...
How high is it raising the RPM ? is it excessive ?
A lot of system raise the RPM when th fans are on because of the extra load on the alternator, fans take a lot of current
Also higher RPM is used by some system to increase fuel flow through the fuel rail and prevent vapour lock in the fuel rail.
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Last edit: 8 years 6 months ago by Andy.MacFadyen.
I tried impinging grounds at computer for fans this changed nothing. New iac new plug end on it. New computer last year. New cooling temp switch and plug. Check iac wiring seems good..
You probably have already done it, but I would look at as many data PIDs as I can, MAF/MAP/ECT/Fuel Trims etc and look for anything out of the ordinary when the idle changes.
I was looking into it and it looks like voltage is off to map with koeo or koer both like 4.73. Gotta no a wire causing it.. I have to get a pin out of pcm...
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