Wonder if this procedure might help?

Document ID# 611504
2000 Pontiac Grand Am
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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:

PasslockT sensor
Body control module (BCM)
Powertrain control module (PCM)
The above modules, with the exception for the PasslockT Sensor must also be
programmed with each module's own vehicle configuration. See the individual
module service manual section.

Auto Learn
Time required, approximately 10 minutes.

Insure that the battery is fully charged.
Use the scan tool in order to clear the DTCs.
Turn the ignition switch from the OFF position to the CRANK position
attempting to start the vehicle. The vehicle will start and then stall.
Leave the ignition switch in the ON position while observing the security
indicator.
When the security indicator turns off, which can take up to 10 minutes, turn
the ignition switch off. Wait 10 seconds.
The BCM and the PCM will learn the new code on the next start attempt.

In article
<a8403cc37fad2a90ca11bca11df28da9@localhost.talkaboutautos.com>,
jdf774@nospam.netzero.net says...

It sounds like a bad ignition keylock assembly.  Happened to a friends
2001 Grand Am that had the same symptoms as yours.  Once it was replaced
everything was back to normal.

I'm good, but I ain't that good.