[BusNit]

I have been going through a stack of repair receipts on my coach. Previous owner had the ECU replaced a couple of months prior to my purchase. On the W.W. Williams invoice it shows the ECU as a DDEC IV. It shows pre 98 series 60 programing. How can I tell if that is the case? They paid $4600+ for the ECU swap and programming. I do know when I plug in my VMSpec dongle to the DDEC port up front, it gets power but no communication.  (So this is a two question post)