2003 Lexus GX 470 Owners Manual - Page 505

KEYS AND DOORS KEYS Since the side doors and back door can be locked without a key, you should always carry a spare master key in case you accidentally lock your keys inside the vehicle. If you should lose your keys or if you need additional keys, duplicates can be made by a Lexus dealer using the key number. We recommend writing down the key number and storing it in a safe place. 1 Master keys (black) − These keys work in every lock. For your Lexus dealer to make a new key with a built−in transponder chip, your dealer will need one of them. Sub key (gray) − This key will not open the glove box. Key number plate − Keep the plate in a safe place such as your wallet, not in the vehicle. 2 3 A transponder chip for the engine immobiliser system has been placed in the head of the master and sub keys. These chips are required for the system to function correctly, so be careful not to lose these keys. If you make your own duplicate key, you will not be able to cancel the system or start the engine. To protect items locked in the glove box when using valet parking, leave the sub key with the attendant. 8