Check Key Fob Battery

WARNING: This page is about a different car, the 2004 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.

CHECK KEY FOB BATTERY
1. Remove key fob battery. Refer to "KEY FOB BATTERY REPLACEMENT ".
2. Check voltage between battery positive and negative terminals, (+) and (-).
  Voltage: 2.5V - 3.0V
NOTE: Key fob does not function if battery is not set correctly.

OK or NG
1. OK: Key fob battery is OK.
2. NG: Replace key fob battery.
  
  Fig 1: Checking Voltage Between Battery Positive And Negative Terminals
  Courtesy of NISSAN MOTOR CO., U.S.A.