3.9 to 5.2 swap PCM problem
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3.9 to 5.2 swap PCM problem
Just did a 3.9 to 5.2 swap in my 1999 Dakota. The donor was a 1999 Durango w/ same trans. and 4X4. I got all V8 parts to swap it so it looks like OEM. The 5.2 was running in the donor so I knew it was a good engine. I got the 5.2 PCM flashed with my VIN and was thinking all was good but it will not start. The 5.2 will start on my 3.9 PCM so I know it's in the PCM. I have spark, guages and fuel pump just no PCM to injector operation. Anyone done this swap? Anyone know about these PCMs?
Last edited by smcluer; Mar 16, 2013 at 01:56 PM.
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no light and it will not start at all on the donor PCM. Think PCM failed? Need to know for sure how the engine will react with a secruity problem. would hope it would stop more than just the injector operations and give a check engine code...??? i got no codes!
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It will start and run for 3-5 seconds, then the injectors will shut down.
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I learned more about the PCM system yesterday. I called the dealer and checked both VIN for the SKIM and found out neither had it and it was not used in '99. Also found out if it had SKIM that the grip part of the key would be gray. Both mine had full metal hardware store keys. They also told me as did magnethead, the engine should start and shut down. The only thing I could find wrong is that the Dakota and Durango, even with same powertrain don't have the same PCM part number. Looking at the electrical pin out chart they are the same? So I found a Dakota PCM with my new engine size and powertrain for $100 in salvage. I am waiting for it to come in the mail.
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The dead goat is alive! I installed the salvage PCM last night and it fired up like it has always been there. Got no lights, mileage stayed the same and the trany still works as it did. I will still send off the salvage PCM for VIN flash and some other PCM work but yes you can swap these PCMs from same year, engine and powertrain and they will run with no problems with the wrong VIN. The tire smoke is a lot better from a 5.2 V8 too!
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I learned more about the PCM system yesterday. I called the dealer and checked both VIN for the SKIM and found out neither had it and it was not used in '99. Also found out if it had SKIM that the grip part of the key would be gray. Both mine had full metal hardware store keys. They also told me as did magnethead, the engine should start and shut down. The only thing I could find wrong is that the Dakota and Durango, even with same powertrain don't have the same PCM part number. Looking at the electrical pin out chart they are the same? So I found a Dakota PCM with my new engine size and powertrain for $100 in salvage. I am waiting for it to come in the mail.
Glad you got it up and running.
