It's none of those. Trust me. This truck has had harnesses swapped out on it and all those things have been tried with multiple different ones. Ever module has been tried. All except the security module. Truck has oil,fuel, and all the other poop. I've done all those things myself and now it's sitting at another smart 7.3 gurus shop and he's had no luck yet either.. This last time after we got it to run fine for about 8-10min and it shut off it a a code of some sort in the security module.