Maximum Defrost  Press the button.
Air flows through the windshield air vents, and the blower motor adjusts to the highest speed.
You can also use this setting to defog and clear the windshield of a thin covering of ice.
Note:   There is also a button on the lighting control.
Note:   To prevent window fogging, you cannot select recirculated air when maximum defrost is on.
Note:   The heated rear window also turns on when you select maximum defrost.