P1504 IAC malfunction
 

Hi,

I have a 2001 Ford Escape v6 4x4 with a High Idle (3k+) and a cel P1504 code.

I disconnect the IAC and it stalls.
I measured the IAC valve resistance and it is within spec. (I tried a new one anyways and the tps as well)
Voltage across the IAC valve reads 12 volts.
Good continuity between pin 83 and the iac connector (White/LightBlue).
VPWR reads 12v.
I don't have a breakout box but was able to determine that pin 83 is shorted straight to ground as I get 0 ohms when metered to neg post of battery.

According to this,

Quote:
(014-00950), leaving PCM disconnected. Measure resistance between test pin No. 83 (IAC) and test pins No. 51 and 103 (PWR GND) at breakout box. If both resistance readings are more than 10,000 ohms and idle speed is normal, go to step 30). If both resistance readings are more than 10,000 ohms and high idle speed is present, replace PCM. If resistance is 10,000 ohms or less, repair short to ground in IAC circuit.
I have 0 ohms from 83 to 51 and 103.

My conclusion is that I need to replace the PCM. Upon all the research I have seen where many people have gotten a used PCM from junk yards etc. and have only had to take them to the dealer to get reprogrammed. I acquired a used pcm. I used a iac solid gasket (homemade) with two small holes to keep the engine around 1k rpms so I could drive it to the dealer.

I explained my situation and the dealer said it can't be done because of the vin number stored in the PCM. Does this sound correct? I even had the manager check with the tech and confirmed that if he did a backup and restore from my pcm to the new(used) one, I would be stuck with a check engine light anyways because of a vin mismatch.

And btw I do not get the short to ground from pin 83 on the new(used) one.

Any help would be greatly appreciated.

Thanks,
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