2000 saturn sl starting problem (plock?)?

I have a 2000 Saturn sl sedan that cranks and starts but immediately turns off. I replaced the battery and crankshaft position sensor. I think it has something to do with the padlock system because the security symbol keeps flashing when I turn the key in acc. Normally it flashes 5 times and stays solid. I tried turning the key in run position for 10 minutes and the symbol became solid but it still would immediately shut off. Can someone please help?!