System Description: Notes

WARNING: This page is about a different car, the 2004 Infiniti Q45. However, it is still accessible from the selected car via links, so may be relevant.

Every electronic key (including transponder) has its own key ID No. However, only an electronic key with the key ID registered in the NATS IMMU and ECM can turn ON while inserted in the ignition key cylinder, allowing the engine to start.
An ignition key (electronic key) with straight contour is adopted to prevent the electronic key from vehicle theft by abuse of duplicated key etc.
If the batteries for the vehicle and hand held transmitter are discharged, using the emergency key integrated into the electronic key, the driver/passenger doors and trunk lid can be operated for open/close, and the steering wheel lock can be unlocked.
NOTE: The engine cannot be started with an emergency key.
If any of ECM, NATS IMMU, steering lock control unit (integrated in the key cylinder) or ignition key (electronic key) has been replaced, or if the trouble diagnosis requires additional registration, mandatory re-registration procedure and registration of the electronic key ID code (if an ignition-key is added) are required.
NOTE: All the keys kept by the vehicle owner re-registration of the key ID (electronic key) shall be necessary.
If the vehicle owner requires, electronic key ID codes can be registered for up to four keys (including the electronic key). In this case, the key IDs shall also be registered.

NOTE:

The key ID code and remote controller ID code for the key equipped on the vehicle have already been registered at factory.
When conducting registration of key ID for repair, part replacement, and electronic key addition, even the registered ignition (standard) key shall be registered again. Therefore, collect all the keys from the vehicle owner.