Hello and welcome! First things first, find/locate "ALL" THE CONNECTIONS GOING TO/FROM" The ECM control module, take them apart, inspect them, clean them really good, spray them with a electrical spray......and see if this solves your problem first. I have seen a ton of time the same problem, and it has most of the time been a wiring problem, and very little module failure's, but you might have one that has failed? Make sure your batteries are in top condition and charged up, as this also could cause your problem you are having. The communication failure that he is seeing might just be that the bad connections are not allowing his laptop to reach the ECM........? IF a new ECM needs to be installed, let a Cummins shop do it, it needs set up for your operating system...... and so it will operate and communicate with the transmission's TCM. If they have the Cummins Insite program, and you give them the engine 8 digit serial number, they can set one up to operate on your engine I beleive. There are places to send your for repairs I have seen on here......
http://www.cummins-sp.com/parts/comp...sories/ecm.htm
http://dieselecmsource.com/catalogse...inesize=Celect