Anyone using stock ECM and harness?

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dart360swinger

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Hey everyone. I'm in the planning stages of my gen 3 hemi swap. I'm planning to buy a complete running car for the swap. I'm looking at an 05 300C. I'd like to use as much out of the donor car as possible; engine, transmission, harness w/ ECM, shifter, airbox and maybe even gauge cluster.
I'm concerned about the ECM needing an input from the other modules not used like ABS. I couldn't find a swap like this in my searching. Does anyone have any input?
 
Hey everyone. I'm in the planning stages of my gen 3 hemi swap. I'm planning to buy a complete running car for the swap. I'm looking at an 05 300C. I'd like to use as much out of the donor car as possible; engine, transmission, harness w/ ECM, shifter, airbox and maybe even gauge cluster.
I'm concerned about the ECM needing an input from the other modules not used like ABS. I couldn't find a swap like this in my searching. Does anyone have any input?

I'm using the stock ECM and all of the stock modules. However, I'm going to use Hotwire's harness. I'm running a '13 6.4L.
 
Do you plan to 'tune' the ECM?
Here is what I'm curious about. I know the ECM can be tuned/reprogrammed/flashed, whatever you want to call it, to not look for an input from the immobilizer. Can this be done for other modules? Will the ECM allow the engine to run, outside of 'limp mode', without an ABS input? Can the ECM's ABS input be shut off with a tuner?
 
I'd like to know the same things.
Can I disassemble my wiring harness, (removing all of the wires I don't need) and reflash my ecm to work without everything that I deleted?
My donor was a 2010 srt8 Chally 6 speed and I'm using everything.
 
Just a FYI, probably not useful for you, but i use the 2015 6.4 SRT including a few of the OEM control modules (BCM, RF Hub, start button) and the hacked up original harness.
What i can tell you is, that if you use the original harness, book some time over at techauthority.com in case you need access to the wiring diagrams.
 
Just a FYI, probably not useful for you, but i use the 2015 6.4 SRT including a few of the OEM control modules (BCM, RF Hub, start button) and the hacked up original harness.
What i can tell you is, that if you use the original harness, book some time over at techauthority.com in case you need access to the wiring diagrams.

Thanks for the advise. I have access to most of the factory info through ProDemand at work though (Acura technician). I've been following your build, great job by the way. Have you gotten the 6.4 to do anything more than idle yet?
 
Thank you!
I have not gotten it any further than cranking and coughing.
Since i have no oil in the engine and no good way to get fuel to the engine (as of right now) i did not take it any further.
It ran after it had been removed, it wanted to run after i removed the ABS wiring, so i think there should be no big problems.
 
I have a company at hand that will unlock the ECU for me and remove ABS and other stuff from the BCM.
In case i absolutely have to use the ABS module, i will find another solution using that.
 
Do you plan to 'tune' the ECM?
Here is what I'm curious about. I know the ECM can be tuned/reprogrammed/flashed, whatever you want to call it, to not look for an input from the immobilizer. Can this be done for other modules? Will the ECM allow the engine to run, outside of 'limp mode', without an ABS input? Can the ECM's ABS input be shut off with a tuner?

Hotwire reprogrammed my ECU.
 
I'd like to know the same things.
Can I disassemble my wiring harness, (removing all of the wires I don't need) and reflash my ecm to work without everything that I deleted?
My donor was a 2010 srt8 Chally 6 speed and I'm using everything.

I think that's basically what Hotwire does. I have no idea how to reflash an ECM, but the wiring harness would be easy to modify. Just takes a little time and patience.
 
HotWire uses the older computers to run anything, from 5.7s over 6.1s to 6.4s.
I talked to them and they can not make use of any computer past 2014 because these are hardware-encrypted.

Have a look at the info they provide for computers: HotwireAuto - Fuel Injected Wiring Harnesses
And look at their price list: HotwireAuto - Fuel Injected Wiring Harnesses

Apparently, if you want to (and can) use an aftermarket harness, these are really good quality and price.
 
I plan to use the NAG-1 trans that will come in whatever donor car I end up buying, so shelling out $1750 for a generic harness is out of the question for me.
While trolling Hotwire Auto's website I came across there list of requirements and some really great info for using the NAG-1 transmission.

Chrysler Nag1/WA580 Transmission
box_pg_ur.jpg

We have developed a complete wiring and computer package to run the 5.7L/6.1L/6.4L Hemi engines and the Nag-1/WA580 transmission found in the LX cars and some Jeeps.
There is a common misconception that this transmission is not suitable for hotrod or muscle car projects. We have been successfully creating systems for this transmission since 2007. The benefit of using this transmission over the 545RFE found in the trucks is that it can handle more input torque and it has a slightly smaller size. Also, all of the Hemi motors from the LX cars and Grand Cherokees came with the Nag-1/WA580 transmission, these can usually be purchased as a package for less than getting the engine and transmission separately. There are a few more items that are needed to make the transmission shift properly and this is why it has not been the first choice for hotrods and muscle cars.

With some planning and understanding this transmission can work very well in your project.

The following items are required to make the transmission shift:

  • Engine Computer
  • Transmission Computer
  • ABS computer and wheel speed inputs
  • Factory shifter
  • Front Control Module
These items along with our new engine/transmission wiring harness (R-0028) and some custom programming make using the modern Hemi and Nag-1 transmission a fairly straightforward project. Detailed information is listed below.
Overall Project
It is best if you have a complete donor vehicle to get matching computers. There are some slight changes in the different years that can cause the parts to not be compatible. If you cannot get parts from the same vehicle then stay with the same year whenever possible. You can call us to see if there are any known compatibility issues with the parts you have.
You need to send as many of these items in to us as you can for testing on the new harness. At a MINIMUM you must send in the ABS computer and the Front Control Module (FCM). All computers that you send in are connected to the new harness and tested with a OE scan tool to verify communication.

Engine Computer
The factory engine computer comes with built-in security when pulled from a salvage vehicle. To use this computer in a hotrod/muscle car application will require that we either remove security or we can use the factory ignition key and SKIM module from the same donor vehicle to make the security work as intended. We can provide a new engine computer if you need one, the new engine computers do not come with security.
Transmission Computer
The transmission computer is a small black computer with two wiring connectors. See a picture of oneHere. A used TCM from a Hemi car is needed, we do not recommend purchasing a new TCM.
ABS computer and wheel speed inputs
The ABS computer must be sent in to us so that we can verify the wiring, there are a couple different types of modules and the wiring is different for each. The purpose of the ABS computer is to provide wheel speed signals to the other computers. If you are using the rear-end out of a donor vehicle (LX car or Grand Cherokee) then the speed sensors on those axles can be used. If you have an older rear-end then we have a tone ring and sensors kit that you may purchase to mount on the back of your transmission. These signals are required to make the transmission shift properly. We do not recommend purchasing a new ABS computer. See a picture of one Here.
Factory shifter
The shifter module from a donor vehicle is required for this system. These shifters have a flat base so installation is fairly simple. The LX car shifter is a shorter item than the Grand Cherokee shifter. You must get a shifter from a car that had the NAG-1/WA580 transmission. The early V6 shifters will not work. The shifter is part of the computer system and tells the other computers what gear you have selected. It also provides the ability to use the +/- shifting feature. Make sure you also get the shift cable and the wiring connector from the donor vehicle as these items will simplify installation in your vehicle.
Front Control Module
The Front Control Module (FCM) is the only part where we do not try to match model year with the other parts. For the FCM we recommend getting it from a 2006 vehicle. Any of the 2006 LX car or Grand Cherokee FCM modules will work. The FCM is a communications module used by the other computers in the system to share information. It is a small silver computer that is bolted to the side of the fuse block in those vehicles. This module must be sent in to us so we can add wiring directly to it, we may also need to do some custom programming to it depending on your setup. We do not recommend purchasing a new FCM.

Please call 479-243-9115 if you have any questions about your Hemi Nag-1/WA580 project.
 
I have researched this for months and have actually disassembled many harnesses as well as many hours looking through wiring schematics and have written my own schematics to disassemble and reassemble factory 04/05 truck harnesses. My research has shown that using the nag1, though not impossible, is very difficult as it requires using the wheel speed sensors as well as using the body modules to shift. The easiest conversion is using a 545rfe, a small block 727, or a manual transmission and to use the 04-08 car or truck harness. The 05 truck ECM is easy to program and would control the 545rfe, or the transmission controls can be disabled to run a 727 or manual transmission. There is some good information on another site that includes my schematic for a fuse block as well as the pinouts that are needed to be retained. If you need that website pm me as I will not give that info openly without a mods permission. In plain English using the nag1 requires Hotwire's harness, programming and assistance which does not coincide with the "using your own harness" as you asked.
 
I have researched this for months and have actually disassembled many harnesses as well as many hours looking through wiring schematics and have written my own schematics to disassemble and reassemble factory 04/05 truck harnesses. My research has shown that using the nag1, though not impossible, is very difficult as it requires using the wheel speed sensors as well as using the body modules to shift. The easiest conversion is using a 545rfe, a small block 727, or a manual transmission and to use the 04-08 car or truck harness. The 05 truck ECM is easy to program and would control the 545rfe, or the transmission controls can be disabled to run a 727 or manual transmission. There is some good information on another site that includes my schematic for a fuse block as well as the pinouts that are needed to be retained. If you need that website pm me as I will not give that info openly without a mods permission. In plain English using the nag1 requires Hotwire's harness, programming and assistance which does not coincide with the "using your own harness" as you asked.

Thanks for the info. Hotwire sells a tone ring and sensor kit for the back of the NAG-1 transmission to deal with the speed sensor issue. You also mentioned the NAG-1 needs to an input from the body control module. Can you elaborate further on this?
 
Hello I am also planning on using nag1 and all modules as mentioned by hot wire I intend to use complete harness and cluster my question is with the abs ,the tone ring kit from hot wire is only using 2 sensors but the abs module has 4 wheel inputs so do you bridge 2 or ignore 2?this has me baffled so any help as I have emailed hot wire several times with no response and being in Australia I really don't want to have to send items across the world
 
I wonder the same thing. My guess is it bridges them. It would look like you were just always driving in a straight line to the ABS module, but would keep it from going into limp mode. Don't know for sure though
 
That makes sense I am hoping to get confirmation by the time I get to the wiring stage ,at the moment in research mode as I only purchased my hemi and Trans 3 weeks ago,once I start I will be starting a build thread to add what I can,my motor came from 2006 300c 5.7 autostick
 
I believe you'll run into issues with the transmission - The factory uses a input from the ABS sensors to regulate the shift points, speed, firmness type crap that new autos do... I used a factory 2005 harness from a Ram and a 2008 SRT8 Magnum harness and made my own for my 6.1L swap in my Charger.... took a day to make the wiring work - granted I used a reprogrammed PCM and manual trans. I am planning on going to a full stand alone... gives me flexibility to modify and tune without sending the PCM out or paying for a tune that is "close"

I had made a PDF somewhere about what wiring modifications are needed to run the 5.7 / 6.1L engines with a factory harness and posted it on Protouringmopar but the site is deceased. I'll look for it sometime if you need it.
 
If you have it you should post it. It would help many people do this swap economically
 
I have researched this for months and have actually disassembled many harnesses as well as many hours looking through wiring schematics and have written my own schematics to disassemble and reassemble factory 04/05 truck harnesses. My research has shown that using the nag1, though not impossible, is very difficult as it requires using the wheel speed sensors as well as using the body modules to shift. The easiest conversion is using a 545rfe, a small block 727, or a manual transmission and to use the 04-08 car or truck harness. The 05 truck ECM is easy to program and would control the 545rfe, or the transmission controls can be disabled to run a 727 or manual transmission. There is some good information on another site that includes my schematic for a fuse block as well as the pinouts that are needed to be retained. If you need that website pm me as I will not give that info openly without a mods permission. In plain English using the nag1 requires Hotwire's harness, programming and assistance which does not coincide with the "using your own harness" as you asked.
I'd love the information please!!!
 
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