Got a 2002 VX SS (Gen III LS1) it will crank but won't start by itself. If given power to the fuel pump through an external source or giving the rails fuel through an external source it will fire and run fine. It threw code "theft deterrent fuel circuit enable" or something similar once on my first scan (Using Envyous Customs program/cable, am also getting the BCM program to check that). Cleared the code and tried starting again, no luck. Started with external power to the pump a couple times and never got the same code again. Fuses and relays are fine. Checked voltage at the pump and it gets 12v for about a second when ignition is turned on but then cuts. Pump doesn't prime nor run on cars power. Yes battery is good. No security light comes on. Obviously has spark ect but no fuel pressure if pump is connected to the cars loom. Pretty baffled right now, tried both keys incase it was a security issue, nothing changed.