See also:

Freeing a frozen door lock
To prevent a door lock from freezing, apply deicer through the key hole. If the lock becomes frozen, heat the key before inserting it into the key hole or use the remote keyless entry keyfob. ...

Safety note
WARNING • Do not disassemble or modify this system. If you do, it may result in accidents, fire, or electric shock. • Do not use this system if you notice any abnormality, such as a frozen s ...

Keys
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 ...