2000 pontiac grand prix gt

I don't know what testing you have done? Make sure battery has a full charge and connections all good. Have a helper crank it while you visually check for spark at the plugs. If spark everywhere, use a gage and check proper fuel pressure and fuel injector pulse, engine cranking. If you want to see if computer is awake, turn on the key, check for ref voltage for any sensor that uses a ref voltage, use a digital multimeter. If nothing, then check voltage and ground circuits for computer. As far as code reader/scanner, pin 16 at datalink connector has to have voltage or the code reader won't work. Just my opinion.

it could be the coil module that the coils set on

The crankshaft position sensor and camshaft position sensor need the car running to throw a code, and won't let you know with only switch on or motor cranking. Bad cam sensor car will still run, bad crank sensor car aMIGHT not start. Current goes in to ICM then to crank sensor. Crank sensor then tells ICM where and when to send fire to plugs.

I had the same problem as n the sensor was bad. It would start the just cut off as n when I messed with the wires it started. That certainly sounds like your having the same problem.