2006 Chevrolet Monte Carlo Owner's Manual - Page 91

It is possible for the PASS-Key® III+ decoder to "learn" the transponder value of a new or replacement key. Up to nine additional keys may be programmed for the vehicle. The following procedure is for programming additional keys only. If all the currently programmed keys are lost or do not operate, you must see your dealer or a locksmith who can service PASS-Key® III+ to have keys made and programmed to the system. See your dealer or a locksmith who can service PASS-Key® III+ to get a new key blank that is cut exactly as the ignition key that operates the system. To program the new additional key do the following: 1. Verify that the new key has a + stamped on it. 2. Insert the original, already programmed, key in the ignition and start the engine. If the engine will not start, see your dealer for service. 3. After the engine has started, turn the key to OFF, and remove the key. 4. Insert the new key to be programmed and turn it to the RUN position within five seconds of removing the original key. 5. The security light will turn off once the key has been programmed. 6. Repeat Steps 1 through 5 if additional keys are to be programmed. If you are driving and the security light comes on and stays on, you may be able to restart your engine. Your PASS-Key® III+ system, however, may not be working properly and must be serviced by your dealer. If you lose or damage your PASS-Key® III+ key, see your dealer or a locksmith who can service PASS-Key® III+ to have a new key made. 2-17