malibu issue

if my theft light is on steadily pass lock is in malfunction mode so if my battery gets disconnected and reconnected will this cause the car not to ever start??

I would say yes......if the light was activated AFTER the vehicle started, it's kind of like a fail safe mode.....the light stays on, and the vehicle will continue to start......

However, if you disconnect the battery, you are back to square one......now if you try to start the vehicle, and the problem is still there BEFORE it is cranked, then the car won't start....

I switched the lock cylinder back to the original after installing another one trying to trouble shooting the theft system.

I realized that when i went back to the old cylinder when i restarted the car i was using a hardware store key, could this be the reason it did not learn the key code??

with the light on 3 days no problem so far, also before never had a light on, just shutting down and hard starting for the past 2 years..

This is a PassLock system...it uses a plain key.....It is the PassKey (I, II, or III)system that uses a resistor or transmitter( in the key head)....