HouseCallAuto 10/3/2012Replace the lock cylinder but do not use the original key, have a new key made by replicating the key code from the cylinder that is removed. You can do this yourself. if you buy ACDELCO lock cylinder, AKA a passlock sensor, it will come with instructions how to rekey the cylinder to match the original. It does not come with a new key.
HouseCallAuto 10/4/2012I assume you will follow your auto repair guide for the specifics, but simply, the only component that has to come out is the radio and the small round bezel surrounding the ignition lock cylinder. All keys become worn and a new key should not be made from a worn key because the wear will be duplicated on to the new key. After you replace the lock cylinder the car will not run until you relearn the passlock cylinder code. I can post it if you need the procedure but the guide will likely have it.
HouseCallAuto 10/5/20121. Verify that the battery is fully charged.
2. Use the scan tool to clear any Diagnostic Trouble Codes (DTC)s.
3. Turn the ignition switch from the OFF position to the CRANK position, allowing the engine to start/stall.
4. Release the key, leave the ignition in the ON position for a minimum of 10 minutes. Do not continue until at least 10 minutes has passed or the relearn will abort. Going over 10 minutes is OK.
5. After the 10 minute cycle, turn the key off for 15 seconds.
6. Repeat Steps 3-5 two more times (3 times total).
7. After the 3rd cycle, the theft system should synchronize to the new Passlock sensor. It should start and run normally.
NOTE: In some cases, the vehicle may start and run before the 3rd relearn cycle. This means that the relearn has finished early, the vehicle should start and run normally from this point.