[Frango100]

You don´t have warranty on the PCM? So the wire repair you did was on the old wire harness and lateron you swapped the harness?

 

[Bruce C]

The old harness had the wire repair. This is a whole new harness. The computer was sent to Florida to have the key lock out removed, they called and said it was toast. They sent up another and I can't find the address or name of the outfit, I'm still looking. I think I found them on ebay. In any case no warranty mentioned that I can remember. Did check to see if any wires were grounded, none found. Checked to make sure all the grounds were good and they are. PCM to mounting bracket, mounting bracket to firewall, ground strap to mounting bracket.

 

[Frango100]

There is no placard on the new PCM from that company you bought it from?

 

[Bruce C]

Just a short update, fuel gauge wire was corroded just outside just prior to going through rear floor, now working. All engine codes cleared with third cpu, no shorts were ever found. Runs fine and passed emissions test. It was on the back burner and finally finished it last weekend. Thanks for all the advice.

 

[Frango100]

Thanks for the update. Good to know that you finally found it. Happy jeeping.:thumbsup:

 

[Jequan12]

Besides measuring the wires from the IAC to the PCM for continuity, you also measured them to ground? Because the problem is intermittent, i suspect a bad connection somewhere or a shaved wire which touches some metal part.

I have the same problem. Checked for air hose leakage, replaced IAC, and the PCM. The idle was at 2000 RPM constant. P0505 code after check engine light came on. 2001 4.7 V8. Idle went down after PCM was installed but started to rise a day later. Check engine came on and the code was back.

 

[Jequan12]

I like the Jeep. V8 4 wheel drive but not taken care of by previous owner. I am not a good mechanic but I will drop off and have the wires traced like you stated and hope this will solve the problem.

 

[Frango100]

Yeh, best to have the wires checked for continuity and short to ground. I had attached the wiring diagram for the IAC at the beginning of this thread. You could print it out and take it with you to the mechanic, so that he know where/what to measure.

 

[Bruce C]

Just a short note Frank, it did take 150 miles before the new CPU finally regained it's memory. I knew it takes awhile but didn't think it would that many miles. As I said all is well now and passing emissions was a good feeling.

 

[hernandez1]

Hello members. Im new to this forum, but love the interaction and great advise. I have the same issue going on with a grand cherokee p0505. so far i have used a test light to check for signal from the pcm and I notice that the pulse of the test light is not consistent. I did find one of the pins at the IAC harness connector was not secured, but did ensure it was making contact. to isolate the issue, my next step is going to be checking continuity from pcm to iac connector. I will update you all when i find something.