Originally Posted by
MerF
All good suggestions, and although it sounds like a newer truck, make sure there's no corrosion on the terminals and the grounds are tight as well.
A bad connection will act fine with little current being drawn but will not do anything once you put a load on it like a starter has. But to me it really sounds like something related to safety/security of the truck..like the coded key or a bypass relay somewhere is tripped. I really imagine a dealer is going to be your best bet, unfortunately.
now that you say that, did the battery on the truck die recently? maybe the alarm starter kill was tripped? try resetting the ecu by disconnecting the battery for 2min and then connect it and try it again.