Battery Current Sensor

WARNING: This page is about a different car, the 2005 Nissan Xterra. However, it is still accessible from the selected car via links, so may be relevant.

Reconnect harness connectors disconnected.
Disconnect battery negative cable.
Install jumper cable between battery negative terminal and body ground.
Turn ignition switch ON.

Fig 1: Disconnecting Battery Negative Cable
Courtesy of NISSAN MOTOR CO., U.S.A.
Check voltage between ECM terminal 71 (battery current sensor signal) and ground.
Voltage: Approximately 2.5V
If NG, replace battery negative cable assembly.

Fig 2: Checking Voltage Between ECM Terminal 71 (Battery Current Sensor Signal) And Ground
Courtesy of NISSAN MOTOR CO., U.S.A.