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I have a 2010 V6 mustang with 70,000 miles. For several months now I have been going through an exchange with the Ford dealership with a PCM issue. I was receiving error codes for emission problems but Ford stated it was my original PCM going bad. The dealership ordered another PCM which took a month to get from there vendor. That PCM supposedly went bad within two weeks which I was getting the same error codes and check engine light. Ford ordered another PCM from there vendor and that too went bad within a week. I have gone through a total of three PCMs from there vendor which the dealership's response was that apparently they had a bad batch of PCMs. I am now waiting for another PCM to come in and its been over a month. The part is covered under the extended warranty I had on my vehicle but I have not been able to drive my mustang due to the dealership stating if I operate my vehicle and due any further damage to it they will not cover it. Kinda at a lose as to how to handle this and is there possibly something else causing the PCMs to fail in my vehicle?
 

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Take it to another dealer. 1 bad pcm can happen , but 3 in a row would be light winning the lottery big time. Sounds like they did not diagnose it right. Could be a wiring issue frying the board when they put it in or there is nothing wrong with them. These kind off pcm/ electrical issues are hard to diagnose and could easily stump a senior tech.

A short on the pcm circuit without much load can fry a pcm easily
 

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I would definitely have the wires checked. My other mustang is a Boss 302. I had a check engine code come up for low voltage O2 sensor. They replaced that, still came back on. Ford said it was the PCM. They had to ship it to Ford racing. Ford racing worked on my PCM twice. Turns out after 3 months of them getting my PCM to work (they lost it, then they miss programed it) turned out to just be bad wiring!

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I would definitely have the wires checked. My other mustang is a Boss 302. I had a check engine code come up for low voltage O2 sensor. They replaced that, still came back on. Ford said it was the PCM. They had to ship it to Ford racing. Ford racing worked on my PCM twice. Turns out after 3 months of them getting my PCM to work (they lost it, then they miss programed it) turned out to just be bad wiring!

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where was the bad wiring?? did you have to replace the whole wiring harness having almost the same issue with my 2010 thanks
 

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where was the bad wiring?? did you have to replace the whole wiring harness having almost the same issue with my 2010 thanks
It's been sometime since I got on this forum. The issue was a o2 sensor wire, ford did the work. Before I bought the Boss 302, the previous owner had the AC unit fixed I believe. Somehow Ford wrapped the o2 sensor wire against something. I believe heat and rubbing of the wire caused to touch metal which sent the false signal. I don't fully remember, it's been 3 or 4 years now.
 

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It's been sometime since I got on this forum. The issue was a o2 sensor wire, ford did the work. Before I bought the Boss 302, the previous owner had the AC unit fixed I believe. Somehow Ford wrapped the o2 sensor wire against something. I believe heat and rubbing of the wire caused to touch metal which sent the false signal. I don't fully remember, it's been 3 or 4 years now.
Thanks for coming back after such a long hiatus. Much appreciated!
 

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Did you get your issue figured out? We bought our 16 year old daughter a 2010 Ford Mustang and are having similar issues. Apparently Ford is no longer making ECMs for this year, as they consider them "obsolete" which left us going to a third party and we've gotten three bad ones. We finally got a shop that was able to pinpoint that the unit is overheating. The car will work fine, AC will be cold, but randomly all of a sudden the AC starts blowing lukewarm air, the car will rough idle, and that seems to be because the unit is overheating. I'm having a hard time believing that we have had 3 faulty units and have to wonder if it's something similar with a wire pinched, exposed or something else and not the ECM itself. But I can't seem to find a mechanic who either knows enough or is patient enough to really dig in to find the source of the issue, everyone's response is to replace the ECM. Would be interested in how your issue was resolved.
 
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