Mode selection
The mode selection button controls the direction of the air flow through the ventilation system.

The air flow outlet port is converted as follows:

Face-Level (B, D)
Air flow is directed toward the upper body and face. Additionally, each outlet can be controlled to direct the air discharged from the outlet.
Bi-Level (B, C, D, E)
Air flow is directed towards the face and the floor.
Floor-Level (A, C, D, E)
Most of the air flow is directed to the floor, with a small amount of the air being directed to the windshield and side window defrosters.
Floor/Defrost-Level (A, C, D, E)
Most of the air flow is directed to the floor and the windshield with a small amount directed to the side window defrosters.
Defrost-Level (A, D)

Most of the air flow is directed to the windshield with a small amount of air directed to the side window defrosters.
Instrument panel vents

The outlet vents can be opened or closed separately using the thumb-wheel.: (if equipped)
Also, you can adjust the direction of air delivery from these vents using the vent control lever as shown.