GMC 2012 GMC Sierra Denali, Owner'S Manual, Page: 247 / 502

Black plate (5,1)
GMC Sierra Denali Owner Manual - 2012 - 2nd - 11/10/11
Climate Controls 8-5
If this button is pressed when
the air conditioning compressor
is unavailable due to outside
conditions, the indicator flashes
three times and then turns off. If the
air conditioning is on and the
outside temperature drops below a
temperature which is too cool for air
conditioning to be effective, the air
conditioning light turns off to show
that the air conditioning mode has
been canceled.
On hot days, open the windows long
enough to let hot inside air escape.
This helps to reduce the time it
takes for the vehicle to cool down.
It also helps the system to operate
more efficiently.
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.
@
(Recirculation): Press to turn
the recirculation mode on. An
indicator light comes on to show
that recirculation is on.
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 those modes, the
indicator light flashes three times
and then turns off. The air
conditioning compressor also comes
on when this mode is activated.
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.
;
(Outside Air): Press to turn the
outside air mode on. An indicator
light on the button comes on to
show that outside is on. When
selected, air from outside the
vehicle circulates throughout the
vehicle. The recirculation mode
cannot be used with the outside
air mode.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
1
(Rear Window Defogger): For
vehicles with this feature, press to
turn the defogger on or off.
It automatically turns off
several minutes after it has been
activated. The defogger can also be
turned off by turning the engine off.
Do not drive the vehicle until all
windows are clear.