True or not?

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
3,890
44
48
44
ZEPHYRHILLS, FL
here is where the problem is...

The cummins ISB's have their own unique cummins ECM that actually drives the engine. Then the dodge trucks have a "PCM" that does two things. Controls the transmission, and acts as a gateway/translator between the Cummins ECM and the dodge body computers. (Its not like our trucks where the ECM can talk to the body directly)

So...in the dodge truck apps, the cummins ECM is programmed to talk only to a Dodge truck PCM; to send instrument cluster info, data, security info, etc... Its not programmed to talk to a medium duty Allison TCM.

Now of course you could swap the cummins ECM to one from a medium duty app and then it would talk directly to the Allison TCM.........BUT it would leave the dodge PCM (gateway) hanging, so none of your gauges, etc would work.

Kinda makes things a lot more confusing even tho it seems like a simple problem to work around... :(

ben

There's even more curve balls than that to it. Before I decided on a DMAX for my swap, I did ALOT of research on the CUMMINS and backing it with an ALLISON. From my research they say that the CUMMINS ECM in the early HPCR engins could talk to the J1939 modules, but the 05+ couldn't. Also I found that many of the 05+ CUMMINS ECM's actually controlled the 48RE's shifting directly, but it still used the PCM to talk to the BCM for the security system and other functions. With all of the curve balls I found in going with a CUMMINS, I decided on an 01-02 DMAX/ALLI combo instead.
 

duratothemax

<--- slippery roads
Aug 28, 2006
7,139
10
0
Wyoming
There's even more curve balls than that to it. Before I decided on a DMAX for my swap, I did ALOT of research on the CUMMINS and backing it with an ALLISON. From my research they say that the CUMMINS ECM in the early HPCR engins could talk to the J1939 modules, but the 05+ couldn't. Also I found that many of the 05+ CUMMINS ECM's actually controlled the 48RE's shifting directly, but it still used the PCM to talk to the BCM for the security system and other functions. With all of the curve balls I found in going with a CUMMINS, I decided on an 01-02 DMAX/ALLI combo instead.

interesting info, thanks!

where did you find that out? I always like learning new stuff, so Id be curious if it was in a thread on a forum or...?

ben
 

THEFERMANATOR

LEGALLY INSANE
Feb 16, 2009
3,890
44
48
44
ZEPHYRHILLS, FL
interesting info, thanks!

where did you find that out? I always like learning new stuff, so Id be curious if it was in a thread on a forum or...?

ben

Can't remember which forum it was, but it was in talks with the guy that did the 03 5.9L swap over to an EXCURSION. He had done quite a bit of research in regards to CUMMINS ECM's as he used an 03 from a FREIGHTLINER in his project, but had a DODGE OS flashed into it. He ran into alot of hurdles and had asked me some questions about the bus system that DODGE used as he had problems with communications codes popping up in the ECM.
 

kroggs

To Slow
Apr 30, 2009
3
0
0
MN
Anyone figure this out yet? I tried on my truck and seemed to do something with the shifts, But then again my truck wasn't exactly warm yet...