I had this happen a couple of weeks ago. Turns out my TCU went out and left me with a parasitic draw that took out the battery and left me with no way in. I fooled around with it for way too long, trying to jump it at the starter motor, etc., before I called road service (mine is AAA) and reported a lockout. Out came the truck and the door was open in five minutes. Should have thought of that from the start.