Doing a quick search showed no real answers. Last night, my security light came on while I was driving. Nothing changed, just the light came on, stayed for a mile, then went off. Going to become an issue?

Sounds like a VAT'* problem. The VAT'* system is the little chip in your key.

I concurr.. when the system senses that the engine is running and it sees a bad resistance it will kick on the light. It is possible that the resistor in the key or the contacts in the ignition switch are going bad.

It is also possible that it'* a trunk lid sensor, but it'* doubtful based on your description.

I had the same issue with my old cutlass. The contacts on the resistor pellet were worn so if they were dirty, my security light would come on.

a new lock cylinder and key should fix the issue.

Okay, this leads me to my next question...

I thought my starter was going out. However, last Friday night, it wouldn't start, and the security light stayed on. I tried the other key and it started right up. I turned it off and tried the old key, but it also worked, so I thought that narrowed out any key/security issues.

Now, what'* the issue? thanks guys!

If you tried your other key the resistor on that is probabaly less worn. With your everyday key it sounds like it'* on the brink of being bad. Try the other key and see if the light comes on again.

Both keys resulted in no start and security light staying on this morning.
Started this afternoon though.

So I can just get a lock cylinder and a new key?

EDIT Would this fix my problem?
https://www.gmforum.com/electrical-133/bypass-vats-92-99-a-279119/