I recently replace an ignition switch/cylinder in my mothers cavalier. It's a 2002, pretty basic no power windows//locks AT tranny. I installed the tumblers and everything by myself, double checked the key code and everything is right. However when we try to start the car the "Theft System" Light blinks. I've tried waiting 10 minutes for it to stop then trying to start it, however the car runs for .5 seconds and shuts off. I've done every other method i know of but nothing seems to work.. Does anyone know if there's a way to bypass, or just get the vehicle to start without towing it to a dealer? Any information is much appreciated, thanks guys.

 

Actually guys i figured it out:
1.) Attempt to start engine (won't start) leave key on for 10 minutes
2.) Turn ignition off for 5 seconds

Repeat a total of 3 times, on the 4thattempt the BCM resets and allows the car to start.

Figured i would post the fix, so others who have this problem would know how to fix it rather than having it towed to a dealer a save of:
Aprx. $65.00 Tow charge
$96.00 Comp hook up
$50.00 +/- Labor

Hope this helps