Add duplicate key (Requires at least one working key):

1. Verify that the new key has “PK3” or “+”
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 key to be programmed and turn
it to on within 10 seconds of removing the
original key.
5. The security light will turn off once the
key has been programmed. It may not be
apparent that the security light went on due
to how quickly the key is programmed. (If
your vehicle does not have a security light
(04-07 Grand Prix, Bonneville, Impala), wait
10 minutes 45 seconds to make sure the key
has been programmed).
6. Repeat steps 1 through 5 if additional keys
are to be programmed.

* Canadian VIN vehicles excluded. On-board
programming not available for these vehicles.
In many cases a Tech II or dealer equivalent
tool would need to be used.