2003 Nissan Sentra Owner's Manual - Page 74

KEYS A key number is only necessary when you have lost all keys and do not have 1 to duplicate from. If you still have a key, your NISSAN dealer can duplicate it. will only recognize keys coded into the NISSAN Vehicle Immobilizer System (NVIS) during registration. Any key that is not given to your dealer at the time of registration will no longer be able to start your vehicle. NISSAN VEHICLE IMMOBILIZER SYSTEM (NVIS) KEYS (if so equipped) You can only drive your vehicle using the master or valet keys which are registered to the NISSAN Vehicle Immobilizer System components in your vehicle. These keys have a transponder chip in the key head. WPD0203 1. 2. 3. 4. Master keys (black) with transponder chip (if so equipped) Valet key (red) with transponder chip (if so equipped) Key number plate Transponder chip (if so equipped) The master key can be used for all the locks. The valet key cannot be used for the trunk lid lock. To protect belongings when you leave a key with someone, give them the valet key only. Never leave these keys in the vehicle. NISSAN Vehicle Immobilizer System KEY - Master and Valet keys: As many as five NVIS keys can be used with one vehicle. You should bring all NVIS keys that you have to your NISSAN dealer for registration. This is because the registration process will erase the memory of all key codes previously registered into the NISSAN Vehicle Immobilizer System. After the registration process, these components A key number plate is supplied with your keys. Record the key number and keep it in a safe place (such as your wallet), not in the vehicle. If you lose your keys, see a NISSAN dealer for duplicates by using the key number. NISSAN does not record key numbers so it is very important to keep track of your key number plate. 3-2 Pre-driving checks and adjustments