No computer communication after stop safely.

My dad's 6.4 received the "Stop Safely Now" message yesterday right after a regen cycle. Pulled over and it died. Contacted a nearby stealership, they had a mechanic about to knock off, he brought 8 different sensors with him to meet up with my dad. They changed out every dpf, egt, etc. sensor one by one to try and find the problem. Of course, no luck. Dad's friend towed him the other 60 miles to the camp. Truck has been in the yard all day. I arrived here, took my Insight CTS and plugged it into his OBD II, and my monitor isn't able to communicate with the computer. We also tried to read DTCs with his Bully Dog Power Pup, and again, the programmer cannot communicate with the computer. ANY idea on what the f*** is going on? Truck has security light flashing when the key is on, ABS, Air Bag lights, and the radio/cd player stays on once the key is off and out of ignition. I'm in a serious bind right now:dunno: