Interesting idea on the key, but yes, it does not start at all right now. I'll try loosening the fuel filter cap or the output banjo fitting more than likely (so as to not contaminate the fuel going into the high pressure fuel pump. I can usually hear the in-tank fuel lift pump priming before I start the truck, and I am not hearing that now, plus the OBDII connection error leads me to believe that I have a problem that may be connected with other electrical components that are not letting the ECM turn on (maybe the key like you said).