98 cutlass theft deterant system

Hi got a 98 cutlass and the theft deterant light started flashing and would not start. Tried to reset it and I think I did by ignition on and held the 1&4 radio buttons till we got the "dashes" and about 5 seconds after that the dash theft light went out and she started up. My question is why did it go on in the first place and what do I have to look forward to or was it just a fluke thing?? any help would be great! It's the wife's car so you know what that means?!

Welcome to AF.

This is an on going thing with GM vehicles.

Typicly its the ignition switch or a pcm problem.
Even a heavy keychain,
one with several things attached, can trip the passlock system.

Also when you start the car make sure the security light is out before you attemtp to start

thanks for the welcome and thanks for the reply. Now funny thing it happenedagain tonight and to be honest not really sure what I di to have it reset but it did. The wifewent out to put the car in the garage and she came in to tell me the light was flashing again after it wouldn't start. Have to definitly pay closer attention from now on and watch the light before we start it. It is getting more annoying we got this one used and love it exept for this stupid theft system. Is there any way of bypassing or disconnecting it? that's probably a real stupid question!
This cara was originally a rental car so the ignition switch is looking more suspect. thanks ! any other help will be appreciated.

No problem.

Actually in the manual that came with the came suggests that when the security light comes on to take it to the stealership and have it diagnosed.

I'm sure on the net thier are some procedures to disable the passlock but IMO its not worth the troubles.
As the dealer with thier magic wand can usually tell what the trouble is.