See also:

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 ...

Jump starting
If jump starting is necessary, see “Jump starting” in the “In case of emergency” section of this manual. If the engine does not start by jump starting, the battery may have to be replaced. ...

Safety
At this time, the Sentra has not been crash tested by the Insurance Institute for Highway Safety. Standard safety features include antilock brakes with electronic brake-force distribution, active ...