Hi Daron. I found this info on the web - I can't verify that it works, but it might be worth a try.
Cheers,
Adding Keys
Important:
• To initiate, this procedures requires that a learned master key be available.
• A total of 10 keys may be programmed to a single vehicle.
• This procedure adds keys only. The procedure does not erase previously learned keys.
• The keys to be learned must duplicate the mechanical cut of the current key.
• If more than one valet key is to be learned, immediately precede each valet key with a learned master key.
1 With a previously learned master key, turn ON the ignition, with the engine OFF.
2 Turn OFF the ignition and remove the key.
3 Within 10 seconds of turning OFF the ignition, insert the key to be learned and turn ON the ignition. The vehicle has now learned the new key.