Want start with key security system issues

RED theft light on steady,flashing when trying to crank it? was it doing the same thing before new fuel pump installed? why new fuel pump? won't start? is it cranking and won't start or no crank no start? what happens when you try your spare PATS key?

Have you checked for fuel pressure at the engine? If none is present, have you checked for the inertia switch position? This will cut off fuel supply acting as if the vehicle has been in an accident. The Passive Anti Theft System (PATS) will prevent cranking of the engine at all if it is active.