See also:

Engine serial number
MR20DE QR25DE The number is stamped on the engine as shown. ...

Relative humidity
Corrosion will be accelerated in areas of high relative humidity, especially those areas where the temperatures stay above freezing and where atmospheric pollution exists and road salt is used. ...

Never leave these keys in the vehicle.
As many as 4 Intelligent Keys can be registered and used with one vehicle. The new keys must be registered by a NISSAN dealer prior to use with the Intelligent Key and NISSAN Vehicle Immobilizer ...