Air Inlet Control
WARNING: This page is about a different car, the 2011 Nissan Murano. However, it is still accessible from the selected car via links, so may be relevant.
While air inlet is in automatic control, A/C auto amp. selects air inlet (fresh air intake, 20% fresh air intake, or recirculation) depending on set temperature, in-vehicle temperature, and ambient temperature.
Courtesy of NISSAN MOTOR CO., U.S.A.