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Discussion Starter · #1 ·
For those of you who haven't seen it elsewhere, I started a project back in October 2007 to 'download' the program from the flash in my truck's computer, and 'disassemble' it to see how it works. A description of the project and a tracking log are kept at Dodge/Cummins ECU

The intent here is to modify the program myself, either with readily available software or perhaps I will write my own. It's also interesting just to know how it works.
 

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For those of you who haven't seen it elsewhere, I started a project back in October 2007 to 'download' the program from the flash in my truck's computer, and 'disassemble' it to see how it works. A description of the project and a tracking log are kept at Dodge/Cummins ECU

The intent here is to modify the program myself, either with readily available software or perhaps I will write my own. It's also interesting just to know how it works.
from what i could actually understand, pretty cool stuff man :thumbsup lots of stuff way over my head though :thud:
 

· Mopar1973Man.Com
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I'm hoping you do come up with a programer for the Dodge Cummins... I would love to see a software program like for the Chevy's:thumbsup

Keep going you got my vote!
 

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Discussion Starter · #9 ·
I made some progress with map table identifaction, and also got the read/write complete so that I can now begin to play with the table values. There's a little check routine that prevents the RAM tables from being modified, but I figured out how to bypass it.

Soon it will be time to make some changes and :peelout
 

· Mopar1973Man.Com
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Wow... I would love to get a full size copy of that timing map you got your web site. Showing engine speed, MAP and timing...:thumbsup

Could you please??? :w:
 

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Discussion Starter · #11 ·
Wow... I would love to get a full size copy of that timing map you got your web site. Showing engine speed, MAP and timing...:thumbsup

Could you please??? :w:
That map is actually generating an adjustment value that gets added to a base timing. The base timing comes from another map.

The problem I have right now is that I've figured out how the word in the code scales to an actual RPM value (divide by 125), but I need to figure out the scale for the rest of the things like temperature and manifold pressure.

I'm going to put up some full-size screen captures of the map windows this weekend.
 

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Discussion Starter · #12 ·
Work continues. I found the map that generates the requested torque from the APPS input and the engine speed. I confirmed this by making some changes to it - I lowered all of the values above 50% throttle (cut it off) and took a drive. The power that used to suddenly appear just before 2000RPM was gone. Just as I had suspected it to be. For fun, I dropped them lower and tried again but it wanted to stall whenever I let out the clutch and tried to go.

At least with the SCI mod, I can just turn the key off for a bit, then back on, and I'm back to stock again.
 

· Mopar1973Man.Com
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That map is actually generating an adjustment value that gets added to a base timing. The base timing comes from another map.

The problem I have right now is that I've figured out how the word in the code scales to an actual RPM value (divide by 125), but I need to figure out the scale for the rest of the things like temperature and manifold pressure.

I'm going to put up some full-size screen captures of the map windows this weekend.
Right on! I would love to see these screens shots. It might give me clues on how to squeeze more MPG's out of the mighty Cummins engines...:thumbsup

Work continues. I found the map that generates the requested torque from the APPS input and the engine speed. I confirmed this by making some changes to it - I lowered all of the values above 50% throttle (cut it off) and took a drive. The power that used to suddenly appear just before 2000RPM was gone. Just as I had suspected it to be. For fun, I dropped them lower and tried again but it wanted to stall whenever I let out the clutch and tried to go.

At least with the SCI mod, I can just turn the key off for a bit, then back on, and I'm back to stock again.
Boy you really are making tracks with the software. Hopefully you keeping good notes on you research so in the near future there might be a plug-in programmer like EFI Live... (Prayin' :thumbsup)
 

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Discussion Starter · #14 ·
Right on! I would love to see these screens shots. It might give me clues on how to squeeze more MPG's out of the mighty Cummins engines...:thumbsup



Boy you really are making tracks with the software. Hopefully you keeping good notes on you research so in the near future there might be a plug-in programmer like EFI Live... (Prayin' :thumbsup)
I actually hadn't looked at EFI Live until just a couple of weeks ago. Now that I know what it is, I can see that it's very similar to what I'm trying to do. My approach is a little different, I'm using a USB cable I made from readily-available parts, and I wrote my own comms program that runs on my laptop (it's Linux, not Windows though.). I found a free (open-source) ECU editor (it was originally for Subarus) that was modifiable.

But, all of the stock ECU programs are different. To make something like this work for everybody, I would have to obtain all of the stock softwares, and find out the location of the maps and calibration variables. Lots of work. The other option is to set up a forum where people could work on their own ECU files and share the resulting definitions. Maybe I could make a product of the cable/downloader program.

Just ideas at this point. There's still a lot of work to do.
 

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Discussion Starter · #16 ·
I discovered that I had two of the maps in the wrong category: the manifold pressure/timing adjustment map, and the manifold pressure/torque limit map. Now that I've got them switched around into the proper places, they make a lot more sense.

Every day it gets closer to the time to play with these settings. But I have to be careful that I know what I'm doing first!
 

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So what model year are you working with?
 

· Mopar1973Man.Com
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The information that he is digging out the ECM is valuable! I'm going to hang out and watch this thread closely and try to learn more about how the Great Cummins works! :thumbsup:beer
 
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