2001 Olds Alero 3.4 V6

Car will turn over and run for about ~1.5secs. The security light stays solid; NOT blinking/flashing. It will NOT turn off during the reset process. Key fob stopped working on both sets of keys. No symptoms leading up to this except one night where RPMs were higher than usual, but that was about a month ago and it hasn't happened since.

-Have tried both the 10 & 30 minutes reset
-Tried spare key/fob
-Replaced ignition switch and lock cylinder (followed with security reset)
-Checked relays, fuses, battery, wires, and fuel pump
-OBD II shows no codes
-Radio ONLY works while cranking or when it turns over for that 1.5 seconds.

Now, I'm thinking it'* a bad BCM, but no symptoms until this happened and it was sudden. Could I be overlooking something?

The electric locks won't work from the fob OR from inside the car, trunk button on fob won't release trunk, radio does not work in the ACC or ON position and turns off as soon as the car shuts off. Anti-theft light on radio blinks constantly.

Have someone spray carb cleaner into the intake while you crank the vehicle....if it starts and runs, as long as you spray, and fuel pressure is ok, then the injectors are being shut down by the SECURITY system....

Need a scan tool to verify that B2958 or B2960 is set...code readers don't read "B" codes, and neither do most generic scan tools....

The usual fix, is a new PassLock sensor.......you replaced the ignition switch.....did you just replace the lock cylinder, or the lock cylinder AND PassLock sensor?