Hey Guys, I was a post somewhere on here about a tcm swap out you can do with the 4.7s and like a jeep 2002 TCM that is a 5 spd. It was said that physically the trannies are identical and that the software is what makes one a 5spd. This is for an auto if you haven't figured that out already. I saw where someone got one for like $30. Was that from a savage yard? I'd like to do that with my truck. Mainly for a little mpg improvement possibilities. and Hell who wouldn't want more gears. I need more info about it.
TCM swap out for jeep 5 spd
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Doesn't work right on a 2000 Dakota 4.7. This is really a better mod for 2001 and 2002 Dakotas. It works on the 2000s but you get a Christmas light show of warning lights on the dash. I did this to my 2000 Auto 4.7 and drove around for like 6months with the warning lights on without any major issues. If I remember right the JTEC(Jeep Truck Engine Controller) PCM on the Dodges use a different bus so it doesn't communicate to the Jeeps TCM, but the TCM talks to the tranny just fine.
I think Jeeps used a CCD bus and Dodge used a PCI bus on the JTEC PCM.
Also its worth pointing out that because of the incompatibility with 2000 PCM and Jeeps TCM, Torque management wasn't enabled, so its a little quicker off the line.
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To answer your question, Yes the Jeep TCM turns the 45RFE into a 545RFE. Look around here (car-part.com) or your local salvage yard. In my opinion, For MPG improvement the TCM, and crank pulley, and perhaps a drop in K&N or FIPK would make a noticeable difference in MPG. Not anything drastic but still. I had these on mine and was getting pretty decent MPG, think close to 25mpg on the highway. I have a simple RC with no options though.
I'm not positive what JTEC stands for, but pretty sure it's not Jeep Truck Engine Controller. :jester:
The CCD bus was used on 00 and previous Dakotas, PCI bus started in 2001 which is the cause for all the warning lights. CCD BUS is a 2-wire system, PCI uses only one wire.
Also, the torque management was only used at and near WOT shifts. It cuts power during the shift. It does not reduce power at low RPM.
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No the torque management reduces power from a stopped start. Its designed to protect the driveline from 'shock' due to sudden acceleration. Theres a few write ups about how to disabled this on here. Ive seen Jeep manuals that say JTEC stands for Jeep Truck Engine controller.
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Ok well perhaps its not just at stopped starts, its during shifting too.
oh sux to hear that. so there is no auto 5spd that used the same bus for the same tranny? I already have a ram air warm air intake and I'm sure I need some new cones but I'm doing good to get 17 mpg avg mixed driving. and what's FIPK Stand for? I also have a 4x4. If I could get 25 highway in either the dakota or 5.2 durango I'd be thrilled.
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Heres a good writeup about torque management although its from an LS2 forum. I still think our torque is reduced from a stopped start as well though. I could tell a difference in mine, felt like it could peel out easier.
http://www.ls2.com/forums/showthread.php?t=361225
http://www.ls2.com/forums/showthread.php?t=361225
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No, I wish they did. I dont even think we can get it flashed with the 545fre program from some aftermarket shop, us 2000 owners have been left out in the cold. The 2000 was the guinea pig of the 4.7 in the Dakota, We got jipped on TB(65mm), Intake(runners too long), Transmission upgrade.
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When I tried it on my 2000 Dakota, the speedometer also didn't work right, so it made the odometer not work right. I drove about 10 miles and it put 4 on the odometer. Not a horrible thing....lol. But dishonest and annoying.
I have one on the Durango and saw increases of 2-3mpgs, depending on driving circumstances. I figure it paid for itself in around 100 gallons, which is nothing in these.
I have one on the Durango and saw increases of 2-3mpgs, depending on driving circumstances. I figure it paid for itself in around 100 gallons, which is nothing in these.
Well I hope the tmc mod is still doable. I don't know much about intake runners and how to make them anymore effecient. I'll look that up at some future date. Bummed about the tcm. I guess I could try it out and just keep the old one to switch it back whenever I want to or when it's time to trade up.
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It is doable, but people get different results. If the PCM isn't reading the BUS right, you never know what is happening. You could throw codes, you could get bells and whistles, your speedometer or odometer might not work, and the thing that I would be concerned with is all the electronic crap that happens with the engine. If it isn't getting the right signals from all sensors, then it could potentially run like crap and use more gas, or worse. I have heard of guys that put up with it and it was fine. But I tried it for 30 minutes and had had enough.
Hey Montana is your 2000 dakota a 5 spd or was that your durango? couldn't I just find a 2000 with a 5spd and take the tcm out of it? Should be the same I'd think...It is doable, but people get different results. If the PCM isn't reading the BUS right, you never know what is happening. You could throw codes, you could get bells and whistles, your speedometer or odometer might not work, and the thing that I would be concerned with is all the electronic crap that happens with the engine. If it isn't getting the right signals from all sensors, then it could potentially run like crap and use more gas, or worse. I have heard of guys that put up with it and it was fine. But I tried it for 30 minutes and had had enough.
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I'm 99% positive that there were no 2000 5 speed autos. They were all 4 speed, so that's why people want to do this mod. My 2001 Durango was 4 speed, and I did the TCM swap to make it a 545rfe.
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I clipped the CCD wires going to the TCM when I installed this. I've been driving 2 years now, and in all that time, I've only had the one P1698 (no comms with TCM) engine code, and a constant CEL.
which are the CCD wires?
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i just did it in my 02 durango..everything works fine.4.7 of course.
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