WARNING: This page is about a different car, the 2003 Nissan Altima. However, it is still accessible from the selected car via links, so may be relevant.
For circuit terminal identification, see Fig 1 - Fig 2.
Fig 1: Circuit Testing Value Chart For Fuel Level Sensor (2.5L)
Courtesy of NISSAN MOTOR CO., U.S.A.
Fig 2: Circuit Testing Value Chart For Fuel Level Sensor (3.5L)