GMC Sierra Denali 2009 Owner's Manual page 168

0
(Defrost): This mode removes fog or frost from
the windshield more quickly. Air is directed to the
windshield and the side window vents, with some air
directed to the floor vents. The system automatically
forces outside air into the vehicle.
The recirculation mode cannot be selected in the defog
or defrost mode. When either mode is selected, the
system runs the air conditioning compressor, unless the
outside temperature is close to freezing.
Do not drive the vehicle until all the windows are clear.
:
(Outside Air): Press to turn the outside air
mode on. An indicator light comes on to show that
outside air is on. In this mode outside air circulates
throughout the vehicle. The outside air mode can
be used with all modes, but it cannot be used with the
recirculation mode.
?
(Recirculation): Press to turn the recirculation
mode on. An indicator light comes on to show that
recirculation is on.
3-22
This mode recirculates and helps to quickly cool the air
inside the vehicle. It can be used to help prevent
outside air and odors from entering the vehicle.
The recirculation mode cannot be used with floor,
defog or defrost modes. If recirculation is selected
with one of these modes, the indicator light flashes
three times and then turns off. While in recirculation
mode the windows may fog when the weather is cold
and damp. To clear the fog, select either the defog
or defrost mode and increase the fan speed.
The recirculation mode can be turned off by pressing
the outside air button, or by turning off the ignition.
#
(Air Conditioning): Press to turn the air conditioning
system on or off. An indicator light comes on to show that
the air conditioning is on. The air conditioning can be
selected in any mode as long as the fan switch is on.
The air conditioning system removes moisture from the
air, so a small amount of water might drip under the
vehicle while idling or after turning off the engine. This is
normal.