System Operation
WARNING: This page is about a different car, the 2004 Nissan Quest. However, it is still accessible from the selected car via links, so may be relevant.
The intake door control determines the intake door (driver and passenger) positions based on the position of the recirculation switch. When the recirculation switch is depressed the intake door motors rotate closing off the fresh air inlet and recirculating the cabin air. If the recirculation switch is depressed again, the intake door motors rotate in the opposite direction, again allowing fresh air into the cabin.
In the AUTO mode, the front air control determines the intake doors positions based on the ambient temperature, the intake air temperature and the in-vehicle temperature. When the DEFROST, or OFF switches are pushed or A/C switch is OFF, the front air control sets the intake doors at the fresh position.