Help!!! How to reset the theft system???

I'm currently having a problem with my 4 cylinder 98 Malibu, when I insert the key and try to turn the car on, only the theft system light comes on, no blinking, nothing. Due to that problem, my car won't start, it won't do anything at all. I had my car sitting there without a battery for about five days because I was fixing other problems.

Anybody knows how to reset the Theft system? I really apreciate it thank you.

been awhile since i worked on anything with that type of problem. Does it have the VATS system, with that little chip looking thing in the key? Can't remember if that was even on any '98 models. You might end up having to tow it into the dealer so they can hook up to the computer and reset it. i don't know of a manual way...sorry. But give them a call as ask what it takes....or maybe someone here can help.

:banghead: i have this problem with my 2000 malibu, the anti-theft blinking light comes on now and then without no control of mines and would not let me start my car, i use the remote to unlock and lock to see if the light would stop blinking and that wont work, and i would get out the car and lock the door and open with the key, that wont work, i would try to open the trunk with the key to see if that would work, nothing. i would have to wait 15 to 20 minutes to wait to see if the the would stop blinking and when that happens i could start the car, and this happens when i have the key in the ignition, i do not know what i do to trigger the light to come on? but every time i leave my car i always press the remote twice, once for the doors to lock, twice to hear the horn sound, to insure me the car is locked. please tell me what i'm doing wrong and what to do to stop this when i see the blinking light come on. i donot have a manual, when i brought the car used it didnt have one in the car.:frown:

same question as above....but i think yours has the passlock system. can be only one of 3 things IF it is the security system causing the problem.

1) the lock cylinder is going fubar.
2) the body control module
3) the wire going from the lock cylinder to the body control module.

the lock cylinder has a sensor in it that when it's turned, sends the signal to the BCM to tell the PCM it's ok to start, provided the lock cylinder is present and functioning. best of luck, and if i am wrong about the system yoru car has, i apologize, but it's been a long ass day/

Search this forum for related topics... I seem to remember lots of posts related to the passlock and anti theft systems....

I have not had this problem yet.... good luck!

Yep. Just look up my posts and you'll see a ton of stuff plus, if you are handy on cars, my way to bypass the system if it isn't a BCM related problem.

I did run into a wierd one the other day. I had a small garage call me to look into a no start condition. They had replaced the whole ignition and decoder in the ignition. They also successfully relearned the "code" and had the car running ('98 S10 blazer). Well, they sat it outside overnight to bring it back in the following nonrelated work. The car wouldn't start. The security light would stay on even if the car was off!!! After double checking everything I found that by unplugging the BCM and plugging it back in, it'd go off and the car would start.

They later ended up replacing the BCM.