Well, thanks to a member on the Cummins forum, I got it fixed. He said the dealer probably reflashed the ECM as a "safety feature" and cannot be reversed. He had the same issue and since it also is tied into the seat belt he unplugged it and looped a wire into the truck side, tricking it to think the belt is attached. I just clipped the wire on the belt side and soldered them together. No more alarm going off and as an added bonus, no more seat belt ding if the belt is not attached.