You can avoid paying a dealer to change the lock cylinder by performing a simple modification on your vehicle. But before you start, you should make sure that your vehicle is one that uses this system. My owner's manual was in the glove box, so I read the section about the security light, (page 2-68) which said: "This light will come on when you turn the key to ON and will stay on until the vehicle starts. Disconnect the battery negative terminal Remove the kick panels below the dash on the passenger side of the car so you can get to the Body Control Module Once the kick panels are off, you will be able to see the module hanging below the. How am I going to see my dealer, when I'm 40 miles from his shop? Thankfully, there is also an entry for "Passlock" in the index of the owner's manual. (page 2-18). It reads in part: "After attempting to start the engine, if the SECURITY. On the 2002 Pontiac Grand Am, Olds Alero, and several other GM cars, the Ignition lock cylinder is the most likely cause of cars not starting because of security system malfunctions. Wear in the ignition cylinder causes the electronics within the security module to present. Most of the posts on m advised doing the modifications through the space in the dash that is occupied by the radio. On my car, however, I could not get sufficient slack in the wires to do the work. If you know that this procedure works on your car, then you can proceed with the modification. CAUTION - If you are going to do this modification, read this entire web page thoroughly, and perform each step. After spending several days reading through most of them, I decided I would try to follow some of the advise presented, and bypass the security system. Three methods were described. All involved modifying the wiring of the passlock system. I decided instead to work with the same wires at the point where they connect to the Body Control Module. So, before you clip your yellow wire, take a few extra minutes to inspect everything you can concerning the Passlock system. From then on, each time the car is started, the Body Control Module checks to see if the signal on the yellow wire matches the stored value. If a key is not inserted into the ignition switch, and the lock cylinder is not rotated to. Of the three, this would make the system behave as though there were no problem at all. The SECURITY light wouldn't be on all the time, and I wouldn't have to worry about re-setting the system with a switch should I lose battery power to. The Body Control Module will then send a signal to the Powertrain Control Module telling it to shut down the fuel injectors. In some model GM cars, the signal from the ignition system is controlled by a resistor embedded in the key.