THAT seems to be the difference. I cannot for the life of me explain why, but any truck that has the squared buttons seems to work. There was a build change somewhere and you must have the newer style! Congrats! You may have an 04.5 ? Engine may be an early build, but the ECM is an updated/newer version.

 

I think my buttons are square-ish, what do you mean? Some are out on the sides of the airbag and some are more centered in the steering wheel. Does anyone have a picture of what buttons this is working on?

 

"It states in TSB 18-004-04:

If the “ECM part number” is 15235113AG, 15235133AG, 15305153AG, or a later revision to these part numbers, proceed to (STEP #3). If not, flash the Cummins ECM in accordance with TSB 18-030-03 Rev. A before proceeding to (STEP #3).

If your ECM part number is earlier than these, it says in TSB 18-033-04 which is a revision for 18-030-03 that you need to purchase a re-man ECU and have it programmed to work. I discussed this with a friend who is a tech at the dealer who confirmed this for me."

copied from this thread here.
https://www.dieseltruckresource.com/...d.php?t=200586