2011 Chevrolet Silverado 2500 HD Extended Cab Owner's Manual - Page 57

Keys, Doors and Windows The security light will come on if there is a problem with arming or disarming the theft-deterrent system. When the PASS-Key III+ system senses that someone is using the wrong key, it prevents the vehicle from starting. Anyone using a trial-and-error method to start the vehicle will be discouraged because of the high number of electrical key codes. If the engine does not start and the security light on the instrument panel cluster comes on when trying to start the vehicle, there may be a problem with the theft-deterrent system. Turn the ignition off and try again. If the engine still does not start, and the key appears to be undamaged, try another ignition key. At this time, you may also want to check the fuse. See Fuses and Circuit Breakers on page 10‑48. If the engine still does not start with the other key, the vehicle needs service. If the vehicle does start, the first key may be faulty. See your dealer who can service the PASS-Key III+ to have a new key made. It is possible for the PASS-Key III+ decoder to learn the transponder value of a new or replacement key. Up to 10 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. 2-13 See your dealer or a locksmith who can service PASS-Key III+ to get a new key blank cut exactly as the ignition key that operates the system. To program the new additional key: 1. Verify that the new key has a 1 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 LOCK/OFF, and remove the key.