WARNING: This page is about a different car, the 2004 Nissan Titan. However, it is still accessible from the selected car via links, so may be relevant.
Check resistance between fuel level sensor unit and fuel pump connector terminals 2 and 5.
Fig 1: Sensor Resistance Values Table
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Fuel Level Sensor Test Terminal Identification