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2003 to 2005 PCM Swap

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2003 2005 pcm swap
146K views 1K replies 44 participants last post by  charged392 
#1 ·
Hi all,

First time posting but long time enthusiast on the hemi. I have myself a 2003 Dodge Ram 1500 2wd with the 5.7L that I am coining "project race truck." I dropped in a comp cam 260 with new lifters, 6.1L valve train, and the bottom end has been rebuilt (after a stock valve spring broke on the stock motor and dropped a valve). I have also done longtubes, true CAI routed to the existing AC fan shroud (AC deleted), 180 Tstat, and is currently running on a superchips 91 tune. Problem is, well it doesn't run that great. The truck weighs with me in it 5360 pounds and I am currently running 15.5 in the 1/4 mile @ 91.7 mph. The trap speed is decent but not lining up with the ET, and I think there is much room to be made with custom tuning.

Now for the 03 issue. I know custom tuning is limited so I bought myself an 05 hemi parts truck (500 bucks complete with motor and trans!) that a buddy and I tore out every electrical harness and module out of. I am planning on doing a full swap to 05 electricals, or at least what we find needed. I have heard of some people doing this with some parts from an 05 (engine harness, PCM, maybe front harness with fuse box?) but I haven't seen it documented well. I plan on documenting every single module and harness in this thread that MUST be used from the 05 in order to convert via plug and play an 03 to 05 for custom tuning purposes.

Some issues that I know of just from pulling out the 05 harnesses:
- abs modules look different
- you need the SKIM from the donor truck to communicate with the PCM. Hence you also need the donor keys and ignition cylinder
-05 has a different gas pedal
- instrument cluster connections are different. This is where I don't see how people have done this without the full cab/dash wiring harness, which connects to the PCM, engine harness, fuse box, fcm and abs module. I have access to reflashing the PCM/cluster to show my current mileage.
-05 has egr and 4 o2s. I would like custom tuning done to delete egr but plan on using 4 o2s like factory (03 only has 2)

I have a wideband O2 sensor which is showing decent A/F at WOT but I really think it needs some tuning down low. I was told that a guy on this forum writes custom tunes, but I may consider local unless someone instructs me what I need to do to get custom tuning done over the web?

My buddy has a Paxton supercharger that I may be installing on this motor in the future. Heres to the beginning of a long but powerful road ahead :)
 
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#2 · (Edited)
Welcome to HTC. :thumb:
Looking forward to your progress.
If you have a Diablo tuner, I know a guy. :lol:
 
#3 ·
Welcome. I just had an '04 swapped to '05. We are still tuning the truck. However, I'm not a mechanic nor am I an electrical specialist. I can tell you from one enthusiast to another, your heading in the right direction for tuning possibilities especially if drag racing is what you have your heart set on. BTW, if you don't install the blower, will you spray the truck?

Good luck!
 
#9 ·
Welcome, Always glad to see another 03 join the herd. I would suggest you talk with Hotwire and see if they can make you the harness to simply plug the 05 PCM in. You will probably need to supply them with both harnesses from the PCM's. No doubt you will need to add a O2s bung. The egr I believe can be deleted in the 05 tune when you have it done. Talk to Keith (CMR Tuner) about what can be done. Good luck.
 
#11 ·
We can tune the 2003 as it is its a tad tricky but can be done. If you swap to the 2005 comp I am not limited and can change a lot of stuff. If you boost it my 05 is boosted and idles at 668 with a big cam a stroker and hauls. If you need tuning send me a PM and I can hook you up.
 
#12 ·
Is Keith for CMR tuning from this forum, what's his username?

I won't be using hardwireauto as I have all the harness and modules from an 05 to do a direct swap. Sold the motor and tranny so I am only a couple hundred bucks deep for everything I need to convert.

Do 05s have more tuning options then 04s without a separate tcm? If so I am glad I scored with the 05 truck.

Will be starting the electrical swap this weekend :)
 
#14 ·
Charged382 is Keith...
 
#17 ·
Just a note, spent the afternoon downloading a couple service manuals. Not as easy as it should have been, but finally got a 05 and a 06 manual. I have a wiring harness I bought a few years ago for the 06+ dual coil plugs, actual year is unknown. Anyway I'll start comparing the print-outs to see how big a hassle this swap will be. This is not my thread but hopefully I'll have something informative to add.
 
#18 ·
I heard it's as simple as splicing in the plugs for the 06+ coils into the 05 harness. I too have the dual coils and valve covers that I will be adding into my 05 swap, but haven't sat down with the service manuals yet to compare the pin outs. If you get to it first red, by all means add it in here
 
#21 ·
I installed the dual coils a few years back. It's simply splicing the 06+ coil plugs (2 wires) to the earlier ignition harness. They are all powered including the injectors from a common 12vdc source (ASD). Then there are 8 individual PCM controlled ground wires. These are marked individually, and actually control the spark by the PCM grounding them at the correct moment. Waste spark is still present, just doesn't use a separate high tension wire but simply fires the companion cylinder's coil.
 
#19 ·
Are you manually shifting at the track? And if you decide you don't want all the headache of a 03 to 05 swap, I have a pretty nasty setup you can follow to make that thing pretty damn quick all while maintaining the superchips tune. Tuning won't do a hole lot as far as et with a cam as small as the 260, maybe 8-10 hp at the most which will be minimal gains at the track. Maybe a 1/10th or 2. If it's a race truck are you open to weight reduction and track prep? Setup is very important . Between a nice cam and a real good healthy stall there is a lot to be had over your setup now along with a nice pair of BV heads to help it breathe .......
 
#20 ·
1 more question, are you running a Stall or gears yet? And I assume you are on stock heads? And where did you make that pass? Elevation and DA can have a very large effect on times in these trucks. Holler at me and I will do what I can to help get you on the right track without the endless headaches of trying to bypass all the 03 tuning issues. You can still make great power with the tuning you already have
 
#22 · (Edited)
IMO, this looks to be a easy swap using the 05 PCM and the original 03 harness. I suggest anyone interested in doing this, print out the pin-outs for the 05 and 03 PCM plugs 1,2,3 and 4 and compare them side by side line by line. I'm using a manual transmission PCM from a 2005 Ram 2500. This and other Ram PCM's can be purchased from your local Advance Auto store ordered from Cardine. I have found them cheaper from online sources but there is no recourse if you receive one doa and/or junk. Cardine will flash your VIN, so everything is ready to go when you receive it. Looking at about $300 for the PCM, another $30 for the flash and about $50-$70 for the core. And if you get one from a salvage yard which I have also done it can be used without flashing your VIN into it.. As stated previously the 05 has four O2s and egr where the 03 has no egr and two O2s. Apparently the 03 4.7 engine also has four O2s same as the 05 hemi as there is a pin reserved for it (C1-#33). I haven't pulled my plug apart yet to see if it is vacant or has a pin in it. Note" that pin #33 is the only difference in plug C1 between 03 and 05. Plug C2 the only differences found was again O2s related were pins #17and #33. And for C3 which is as far as I need to go the only difference is pin #10 and again O2s related. As for the egr C2-#22 is the connection point for the signal. I've been assured that the egr can be disabled using a CMR tune as can the rear O2s so I'm not going to connect it. Anyone with questions or information post it up and we'll see if someone can answer it.
 
#23 ·
Disassembled a spare plug I had and removed the pins. Just wanted to see if indeed I could get the pins out in usable condition :). Trying to hunt down a PCM now, apparently the 05 manual PCM aren't in abundant supply...
 
#24 ·
Anyone have a update?
 
#25 ·
Hey guys, sorry for no update. I have been busy with my last year in Engineering school but I do plan on tackling this job in the next month or so. I had hit some snags on installation timing as my motor suddenly started running like absolute crap. I didn't want to go ahead with the PCM swap until I troubleshooted the issue.

My engine had run decent on the superchips tune with the new cam; I had put probably 2000 miles on it. Suddenly overnight, the thing wouldn't idle, was dieing at stoplights and had a huge decrease in power. I had a buddy at a dealership go through a full diagnostic with their OBD tool and all signs seem okay. We weren't able to pinpoint the problem, but fresh fuel and just running it seems to have cleared up most of the issues. He will be helping me with the build and suggests I go ahead with it with the way it is running now (although not as good as right after the cam swap, but he truly thinks its a tuning issue). The thing about this tool was that, even on a 2003 PCM, it had the functionality to bump the idle up. A setting of 800 rpm basically cleared all driveability issues.

I will post back once I start the swap.
 
#26 ·
You are going to need a tuner to CMR tune. If you went ahead and got the tuner you could do some data logging and see where you are currently at.
 
#27 ·
I will be getting to work on my pcm swap at some point as well. I have the second o2 sensor, pigtails, 05 pcm, bought the diablo intune and had the exhaust modified to remove the cat and rear o2's so I am ready to get at it. Between me and my kids fighting off a nasty bug for the last month and then the cold of winter setting in (my shop has sh***y heat) I have been delayed time and time again.
Regardless of delays I am fully invested at this point and it will happen eventually.
 
#28 ·
I certainly understand how life gets in the way of things. Hang in there and you'll get it done. I've learned to just roll with it all.. I would certainly like to find a 05/04 2500 manual trans PCM.
 
#30 · (Edited)
I went to the local auto parts to get the 03 manual trans PCM that I'm using and found that Cardone provides most all of the PCM's to everyone including the Dealer. So I checked directly with them and was told out of stock and no idea when one might show up. I'm supposedly on a list but I won't hold my breathe. The dealer gave me the grand run around. We identified one and parts guy told me it was $850 with a big grin. I told him ok, order it.... He finally got back to me and said he couldn't get one... This leaves using a automatic PCM flashed to manual which has it's own issues.. But can be bought for $100... plus the reflashing. If anyone has a lead on "05 2500 manual transmission" PCM please contact me.


Edit: Just checked Car-Parts.com and they don't have one listed.
 
#31 ·
I bought mine from flagship one. They didn't list mine on their website but did find one when I called them. Maybe they can help.
I called my local wreckers and they had nothing.

Good luck!
 
#32 ·
Thanks,
 
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