GM Service Manual Online
For 1990-2009 cars only

Your vehicle has a passive theft-deterrent system. The immobilizer system prevents your vehicle from being started by unauthorized persons.

Your vehicle has a special key that works with the theft-deterrent system. There is a transponder in the key head that is electronically coded. The correct key will start the vehicle. An invalid key immobilizes the engine. The immobilizer system isolates the power supply to the ignition system, the fuel pump and the fuel injectors.

The engine immobilizer is activated after the key is turned to LOCK and removed from the ignition. The security light located to the right of the clock will flash when the immobilizer is active. If the light does not flash after removing the key, have the system checked by your dealer.

The immobilizer system works when you turn the key to START. If the immobilizer system does not recognize the electronic code, the engine will not start and the security indicator will continue blinking. If your key is ever damaged, you may not be able to start your vehicle.

When trying to start the vehicle, if the engine does not start and the security light continues flashing, the key may have a damaged transponder. Turn the ignition off and try again.

If the engine still does not start, and the key appears to be undamaged, try another key. At this time, you may also want to check the fuse. See Fuses and Circuit Breakers . If the engine still does not start with the other key, your vehicle needs service. If your vehicle does start, the first key may be faulty. See your dealer who can have a new key made.

Up to five keys may be programmed for the vehicle. If you lose or damage your keys, only a GM dealer can have new keys made.

If you are ever driving and the security light comes on and stays on, you will be able to restart your engine if you turn it off. The theft-deterrent system, however, is not working properly and must be serviced by your dealer. Your vehicle is not protected by the theft-deterrent system at this time.