Anti-theft system reset?

Hi, I replaced a stereo in my 2001 Chevy cavalier and after the car won't run over. The theft light comes on when the key is turned. Can you tell me if there is a reset procedure to get it working again? Thanks!

Have a 99 chevy cavalier and it wont start! When I turn the key the only thing that comes on is the radio and the theft system light, this light does not blink it just stays on. I do not have a remote for this anti-theft system. How do I override this theft system to start my car?

My theft system light came on and when I try to start my car it stalls out on me and shuts down.

My remote locks and unlocks the doors, but no head lights flash nothing? Why?
Car listed above is a Z24.

Thanks! But can I install a anti sym. In yet? Buy! A kit from. Amazon?

I was working on the car and accidentally hit the the positive post on the battery. Now it won't start. How do you bypass the theft system?

Just replaced the starter in my car and now it wont start. Anti-Theft light on dash comes on, doesnt blink at all, just stays solid. How do I reset the pass code or reprogram it so it will start? Thank you for your time on this matter, anything will help!

Thank you for your reply, that worked. Thank you again for your time, Gina

The theft prevention system has been activated and the car will not start. The manual is not clear on how to reset the system. How do I reset the theft prevention system?

Hi Ed
you need a charged battery to perform the following.
Is your antitheft light flashing or on steady?

If flashing then
leave key on for 12 minutes minimum hopefully anti theft light is now on steady
do not disturb or 12 min starts again.
Turn key off
attempt restart

some folks have reported up to 3 attempts at the above is nessacary to perform reset.

If keen do a search on passlock

I believe your cavalier is fitted with passlock 1 and not passlock 2

Regards

Don
New Zealand

My car only goes 10 miles per hr and the theft system light came on , I had to have it towed home whats up?

One morning my anti-theft in my car triggered because of my inexperience in mechanics or inner workings of a vehicle the key cylinder tumblers were not working properly to be able to turn or crank the car over with my key, it would not budge at all. I then foolishly removed the key cylinder in a frantic attempt to be able to get to work on time the anti-theft then trigger the car are though able to start and crank over but yet shut off in minutes of it starting up. I tried getting a new key cylinder with key and pass-lock and try to have the computer in the car relearn the new past lock and key but in many failed attempts was not able to do so. The car still starts it up and then shuts off. I figured that I would attempt to call somebody and I told them of the situation at hand of what I was going through and what I have done and what was the results from those things that I did and they told me well the problem was you need to have your body control module or engine control unit flashed to be able to learn a new pass-lock and key. Then and only then will the car start and crank over and run properly after delivery learning process. I have two questions: 1.) Is this true about the flashing?
2.) If question one is true then what is the location of this unit or module that is needed to flashed? Thanks