It doesn't have power locks or doors or anything fancy so no fob. But will not start, turns over wont start. They have been through checking battery, fuel pump, fuses, etc. Nothing found. Last guess is that its the security system. Does anyone know the specific process for an 04 Nissan Sentra to reset it? It is the last hope.

If you're getting a red security light on the dash then it's a security problem, if not then that's barking up the wrong tree. Does the car scan? If not, check power to the ECM. If it does scan, check the start signal fuse (usually 5A or 7.5A in the inside fusebox).

They checked all the fuses last night went through both fuse boxes, they checked the solenoid, the crank sensor, etc.