System Description: Operation

WARNING: This page is about a different car, the 2004 Infiniti M45. However, it is still accessible from the selected car via links, so may be relevant.

The lock and unlock switch on driver's door trim and passenger's door trim can lock and unlock all doors.
With the door key inserted in the key cylinder on front LH door, turning it to "LOCK", will lock all doors; turning it to "UNLOCK" once unlocks the corresponding door; turning it to "UNLOCK" again within 5 seconds after the first unlock operation unlocks all of the other doors. (Signals from front door key cylinder switch)

Key Reminder Door System

However, if the electronic key is in the electronic key cylinder and one or more of the front doors are open, setting the lock & unlock switch to "LOCK" locks the doors once but then immediately unlocks them. (Combination signals from key switch, door switch)