I suspect your security system is locking you out and the security light is flashing when this happens
I am giving you the relearn procedure to reset the system.
PASSLOCK REPROGRAMMING AUTO LEARN
IMPORTANT: Due to component variability, the vehicle theft deterrent (VTD) system must have the learn procedure performed regardless, if the vehicle starts on the first ignition cycle after a VTD repair.
You must perform a theft relearn procedure if any of the following components have been replaced:
" Passlock Sensor
" Instrument Panel Cluster (IPC)
" Powertrain control module (PCM) The above modules, with the exception for the Passlock Sensor must also be programmed with each module's own vehicle configuration.
Time required, approximately 10 minutes:
1. Insure that the battery is fully charged.
2. Use the scan tool in order to clear the DTCs.
3. Turn the ignition switch from the OFF position to the CRANK position attempting to start the vehicle. The vehicle will start and then stall.
4. Leave the ignition switch in the ON position while observing the security indicator.
5. When the security indicator turns off, which can take up to 10 minutes, turn the ignition switch off. Wait 10 seconds.
6. The BCM and the PCM will learn the new code on the next start attempt.
Wednesday, August 18th, 2010 AT 3:36 PM