NO START SOLUTION: 2000 Alero, 2.4L, turns over but doesn't start, security light turns on then off then after a few seconds light turns back on SOLID, SOLUTION: repaired corroded terminals on BCM (located on passengers side under the dashboard). Humidity from blower or other source leaked onto terminals and coroded them away. The symptoms actually started months ahead of time. First the door locks stoped working, then the door chimes and lights, finaly the car failed to start. It would turn and run for about a second and then die out. The security light would remain on solid. The 10 min reset doesn't work in this case.

Good tip, I've seen this a few times before at work.