Fresh/Recirculated Air Control
WARNING: This page is about a different car, the 1997 Honda Civic del Sol and 1997 Honda Civic. However, it is still accessible from the selected car via links, so may be relevant.
The position of the fresh/recirculated air door (part of blower unit) determines whether fresh (outside) air or recirculated (inside) air enters the heating system. This door is controlled by an electric recirculation control motor.