WARNING: This page is about a different car, the 2003 Nissan Murano. 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 (main) connector terminal 2 and 6.
Fig 1: Terminal Resistance Value Based On Position
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Checking Fuel Level Sensor Unit And Fuel Pump