I finally decided to do the 05 pcm swap on my 03 Ram 5.7. Everyone made it sound so simple and I haven’t had anything but problems. The swap itself was simple. But my problem now is that the truck won’t turn over, won’t click, nothing double checked all my wiring again everything matches up. It’s been starting up the past couple of days. I started it today to record a log and I let it stall before it started recording. Went to crank it back up and then that’s when nothing would happen. Keith has been working with me to tune it and he has helped out a lot with all of my questions and problems. Now I’m totally lost.
03 to 05 pcm swap problems
Waylon5.7
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Check ASD relay.. didn't you say the fuel pump runs when the key is turned on?
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There you go... don't know how you started it before if your truck is skim enabled. But now you need to figure out how to either remove it or make your 05 pcm compatible with it.
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yeah and idk how to do either lol. I’d prefer to just remove it. That sounds more simple
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Might try this..
https://www.naxja.org/forum/showthread.php?t=1062275
https://www.naxja.org/forum/showthread.php?t=1062275
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keith tuned out the skim and it didn’t do anything different? That’s basically what that person is saying to do
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It looks like from a little reading, if you vin flash the 05 pcm and have the skim set to blank when you plug it back into your truck it will accept the skim code and run.. If you have a non-skim pcm and you stick it into a truck with skim the pcm will became a skim only pcm. Good luck..
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Did you unplug the immobilizer and set the pcm to blank at the same time.
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do you mean did I unplug it when I installed the skim off tune? Or did I unplug it after unplugging the pcm?
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I believe the immobilizer should be unplugged when a pcm is plugged in that isn't skim active. Say if you have a truck with skim and you want to test a pcm that isn't skim active you can unplug the immobilizer and the clean pcm will not become skim active. If the clean pcm is plugged into a skim truck it will become skim active. Setting a pcm that is skim active to blank is not the same as a pcm that is not skim active. (I think)..
The majority of 03's did not have skim so most pcm swaps don't have problems. I have no personal experience with dealing with skim/immobilizer and would remove it if I had it on my truck. A pcm with a vin mismatch will not keep a truck from running normally. As I understand your truck was running with the 05 pcm with a mismatch vin. Then all of a sudden it wouldn't start anymore. What was done just before it stopped running?
The majority of 03's did not have skim so most pcm swaps don't have problems. I have no personal experience with dealing with skim/immobilizer and would remove it if I had it on my truck. A pcm with a vin mismatch will not keep a truck from running normally. As I understand your truck was running with the 05 pcm with a mismatch vin. Then all of a sudden it wouldn't start anymore. What was done just before it stopped running?
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Do you have a gray key for your truck? I didn't know 03 had SKIM, mine didn't have any issues like this and I didn't get a vin flash either on the new 05 PCM. Is the immobilizer a separate module somewhere on the truck? Or is it integrated into the computer system somewhere?
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I have a grey key. I have the Laramie. The immobiliser is seperate it mounts on the key cylinder.
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I just installed the first tune that was wrote. Fired it up and let it stall out before I could record a log. Went to crank it back up and then nothing. But since the park neutral ground had something to do with it I think that could’ve caused something else in the pcm to go out. Idk.
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As I understand how this works. The 05 pcm was clean, not skim activated. You installed it with the 03 immobilizer plugged in. This activated the skim in the 05 pcm embedding the immobilizer's secret pin in the newly installed 05 pcm. This internal pin is different then the key's programing pin. Normal operation is, key is inserted and talks to immobilizer, if it is correct key the immobilizer then sends pcm it's secret pin to confirm pcm has correct secret pin. If good it starts. A backup check may include checking the vin. Since your vin is not updated the check failed and couldn't start. The updated file you loaded being different may have cause the vin check that failed. I would remove the immobilizer, and talk with a pcm repair shop asking if they can deactivate the skim, cleaning the pcm and flash in the new vin. This should eliminate the skim function. If you have a spare 05 pcm that is not skim activated and you remove the immobilizer before plugging it in I think it will run even with a mismatch vin. But you need to talk to someone who knows what they are doing and be satisfied with their answers.
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I was scared to give them an 03 vin I was scared it would still have no tuning options just like the 03 pcm
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My 05 pcm is also using the 03 vin without issue.
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So basically what he should do is have the sentry unplugged and have the pcm vin flashed to his vin and plug it back in with no sentry. If that doesn’t work then have pcm vin flashed and sentry key relearned like stock
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