when my 05 6.0 died like that, it did the same thing, just died and would crank, but not start. it did not throw any codes either. I finally got it to throw a code for the dealer by getting it to crack over on ether...I think it was just the ipr, but the dealer replaced both the hpop and the ipr. runs fine now 12k later, and now that the parts warranty is up, I thoroughly expect it to go again anyday.