Late-model Nissan cars and trucks come with one of two kinds of key systems. One is the standard mechanical key, which comes with a keyless-entry remote-control key fob. The upgraded key is known as the Intelligent Key. This key houses an internal battery, while the standard key does not. However, the standard key's remote-control key fob does contain an internal battery. You can change either battery yourself; both setups use the same battery type.
Flip the Intelligent Key over to expose its backside. On the back, you will find a small lever. Pull this lever down to release the backup key from the assembly.
Insert the tip of a small flathead screwdriver into the slit on top of the Intelligent Key (above the backup key's storage). Turn the screwdriver to open the Intelligent Key.
Lift the old battery out with your finger. Insert the new battery, with the plus sign (+) facing the back part of the casing. Push the two pieces together to snap the Intelligent Key's latches. Insert the backup key back into its mount.
Insert a coin into the fob's key chain loop. Twist the coin to pry apart the key fob.
Lift the old battery out with your fingers.
Insert the new battery with the plus sign (+) facing down.