2000 Pontiac Grand Prix GTP crank no start

Try spraying a little starting fluid down the throttle body. It should run a few seconds on that. If so it's a fuel problem. If the security system was active when the battery cable lost connection the security system has been triggered. Try locking then unlocking the vehicle with the key fob. I have a 2000 GT that I don't drive much. The battery went dead while the security system was active. When I installed the new battery the alarm started blaring (horn and lights). I locked and immediately unlocked the vehicle with my fob and it was fine. When you replaced the PCM did you have the new PCM programmed using your VIN? You should have. Hope that helps! Jim

The new pcm is plug and play. It has a performance tune and Pass key was disabled. It would require a relearn but no security light is present. Also does the security system disable the fuel pump or just the injectors? The fuel pump doesn’t prime unless the relay is jumped.

I figured out the problem... there are many wires in the PCM harness that are shorted to ground. For instance, the Ignition control wire from PCM to the ICM has 12.8V but also 365Ohm connection to ground! My conclusion is to replace the entire harness but I will try to reroute the few if not many wires that are shorted. Also my ICM ground where it’s bolted to the transmission housing had ~400ohms to the battery and Alt ground. Someone help me out as to what else is grounded by these wires(on transmission) so I can easier figure out why I have no fuel. Thanks