Override Anti-Theft Lock on 2002 Chevy Cavalier


Asked by Jul 28, 2016 at 11:17 AM about the 2002 Chevrolet Cavalier Base Coupe

Question type: Maintenance & Repair

Bought a beater car just to get from Illinois to Texas, took out the passenger
seat for more cargo room, went to start the engine and the Theft System light
came on and it wouldn't even try to start. Tried several crazy work arounds
from the internet -- turned ignition on, pressed the gas for 60 seconds, off for
60, unlocked door with the original key, left then right, then left again,
unplugged battery, plugged back in... nothing. Battery had corrision, so put a
new battery in, still nothing. Any ideas? Anyone with similar experience on
unlocking the "Theft System" in a 2002 Cavalier??? Any help is greatly

2 Answers


Don't really know why removing the seat would trigger the security system. If you clipped some wires that might have done it. HTH. -Jim

Justin Hatfield

This is the dreaded antitheft security system. Look for a picture on the dash when this happens that says SECURITY or a picture of a car with a lock through it. This a visual indication that something in the car's antitheft system is failing. In most GM cars and trucks there is a hidden system that most people are unaware even exists. From the moment you put your key in the ignition, there begins a constant line of communication between your key's security chip or transponder, to the ignition's lock cylinder, and then to the car's TDM (Theft Deterrent Module). These 3 parts are in CONSTANT communication. If the key is in the ignition, then these parts are sending signals to each other. The security light illuminates when that signal gets broken, or not seen at all. When the communication breaks, the car misinterprets this as an attempt at theft and goes into antitheft mode. (like it thinks it's being hot wired) The car shuts down because it is not getting that signal from YOUR specific key. This is why the security light turns on and shuts down your vehicle. It will either turn off the starter, or the fuel injectors. The vehicle may run for 2-3 seconds before shutting down. This link explains it pretty well. http://www.diy-gm-security.com/ http://newrockies.com/

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