Im trying to help my neighbor get a mustang going he inherited from his buddy after passing away. The car died one day and never started again. KOEO the check engine light never comes on. When the diagnostic port is jumped the check engine light come on and stays on (never flashes). I verified power and grounds at the ecm were good. I pulled the computer out and opened it up to find what I belive is a blown resistor that connects to the first mosfet closest the the failed component. Any suggestion on if I should do for repair would he appreciated and hopefully somebody knows what this part is so I can order a new one. Thank you for your time!!!
Computer repair advise
- Thread starter sammie9271
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ECU Exchange specializes in the re-manufacturing and repair of engine control modules.
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thatblackfoxbody
Member
Have not seen a PCM fail like that before. A short somewhere could have done it. Got a picture of the bottom of the board to see the resistor component legs? Swapping the computer for a refurbished one may be a good move, but a repair could be cheaper if you already have the tools.
Shakerhood
20+ Year Stangneter 
I have good soldering equipment and feel comfortable replacing anything recommend just to try but I see one leg goes to the closes mosfet but the other leg i can't see any connections making me think this board has two layers... I took a picture of the backside and pointed a pen at each leg. I guess start by removing and testing the mosfet?
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I posted the response below on the thread hopefully that works.
Do you have the ability to test the computer components (and the knowledge)?
Just send it off to the Exchange and they will check out all the stuff and update needed components.......easey peasey.
Just send it off to the Exchange and they will check out all the stuff and update needed components.......easey peasey.
It looks like either a hard short or the EEC got a polarity reverse.
Either way, I would send it in. Replacing components is one thing and the ability to test it afterward is another.
Either way, I would send it in. Replacing components is one thing and the ability to test it afterward is another.
Any recommendations on somebody I can sent it to that has a quick turnaround time?
Home - ECU Exchange
ECU Exchange specializes in the re-manufacturing and repair of engine control modules.
We've had lots of dudes send their EEC to these guys and so far, so good.
When I find my round-tuit, I'll be sending mine in for a refurb and to my knowledge, there's nothing wrong with it.
gkomo
now i can hopefully expect to receive the shaft
+1 on ECUExchange. I've said it throughout many threads, but nothing was seemingly wrong with my ECU, car ran fine, no issues. Sent it out to ECUExchange just for piece of mind (since unknown condition of ECU and they are old now) and they found many things 'wrong' with it and fixed the issues they found. I'd send a Fox ECU in even if I had no discernable reason to.
pats91
15 Year Member
Ahhhhh, I've sent a half dozen of them to EcUExchange, maybe more, how many laptop or desktop computers are still in use in original condition? Fones too for that matter.
Diodes, transistors, transformers have all evolved, bigger, better, faster, more.
crappy pic but those are computers from 1999 thru 2015. Now you have a computer in your hand, our junk is the FIRST generation of automotive computer control.
send it in, piece of mind.
revcor
Member
If you don't mind sharing, what specifically were the issues they found and corrected? The idea of issues that were physically present, but hadn't yet manifested in how the engine runs, perhaps because they become relevant only under certain conditions not yet experienced, or were caught when their effect on running was so slight it wasn't yet noticeable, etc. etc. is very interesting to me. It's like finding and treating a health problem in a human that'd been silently waiting to kill ya
Shakerhood
20+ Year Stangneter
Mine had quite an extensive list of items they had to repair, including the power supply like yours, its been about 3 weeks since I shipped it and its due back here on Saturday.This is what they sent me via email when my computer was repaired a few years ago.
Keyworksecu in VA only place I'd recommend for stuff I'm not willing to do myself. No canned generic, we replaced something that doesnt exist replies. He has plenty of videos repairing old ford eec iv's, many others wouldn't or couldn't fix. More know for the trucks ecu's though, he charges $150 for the fox body ecu's
View: https://www.youtube.com/watch?v=R7sQrWtes8I
That's usually an over voltage issue, I'd check for more issues than just that if you plan on repairing it yourself, betting its not the only failed component..
View: https://www.youtube.com/watch?v=R7sQrWtes8I
That's usually an over voltage issue, I'd check for more issues than just that if you plan on repairing it yourself, betting its not the only failed component..
I would contact Fox Mustang Restoration in Locust, NC. They specialize in ECM rebuilds.
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