Page 258 of 539

Black plate (3,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Climate Controls 8-3
Climate Control Systems (with Air Conditioning)
With this system the heating, cooling, and ventilation can be controlled.
1. Fan Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Control
4. Defrost
5. TEMP (Temperature Control)
6. Air Recirculation7.KRear Window Defogger (If
Equipped)
fOutside Heated Mirror (If
Equipped)
8Outside Air (If Equipped)
TEMP (Temperature Control):
Turn clockwise or counterclockwise
to increase or decrease the
temperature inside the vehicle.
9(Fan Control): Turn clockwise
or counterclockwise to increase or
decrease the fan speed. Turn the
knob all the way counterclockwise
to turn the fan off.
Air Delivery Mode Control: Press
Y,\,[, or-to change the
direction of the airflow. An indicator
light comes on in the selected mode
button.
Y(Vent): Air is directed to the
instrument panel outlets.
\(Bi-Level): Air is divided
between the instrument panel and
floor outlets.
[(Floor): Air is directed to the
floor outlets, with some air directed
to the windshield and side window
outlets.
-(Defog): This mode clears the
windows of fog or moisture. Air is
directed to the windshield, floor
outlets, and side window vents.
0(Defrost): Press to clear the
windshield of fog or frost more
quickly. Air is directed to the
Page 259 of 539

Black plate (4,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
8-4 Climate Controls
windshield and the side window
vents. The system automatically
forces outside air into the vehicle
and the air conditioning compressor
will run, unless the outside
temperature is close to freezing.
Do not drive the vehicle until all the
windows are clear.
SeeAir Vents on page 8-8.
@(Recirculation): Press to turn
on recirculation. An indicator light
comes on. Air is recirculated to
quickly cool the inside of the
vehicle. It can also be used to help
reduce outside air and odors that
enter the vehicle.
8(Outside Air, If Equipped):
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.
f(Outside Heated Mirror, If
Equipped): Press to turn the
heated mirrors on or off. See
Heated Mirrors on page 2-16.
A/C (Air Conditioning): Press to
turn the air conditioning system on
or off. An indicator light comes on to
show that the air conditioning is
enabled. If the fan is turned off, the
air conditioner will not run. The A/C
light will stay on even if the outside
temperatures are below freezing.
Rear Window Defogger
K(Rear Window Defogger, If
Equipped): Press to turn the rear
window defogger on or off. An
indicator light on the button comes
on to show that the rear window
defogger is on.
The rear window defogger only
works when the ignition is in ON/
RUN. The rear window defogger
stays on for approximately
10 minutes after the button is first
pressed. Each subsequent press,
the rear window defogger stays on for five minutes. The defogger also
turns off if the ignition is turned to
ACC/ACCESSORY or LOCK/OFF.
If equipped with heated outside
mirrors, they turn on when the rear
window defogger button is on. They
help to clear fog or frost from the
surface of the mirrors.
{Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.
Page 262 of 539

Black plate (7,1)GMC Sierra Owner Manual (GMNA Localizing-U.S/Canada/Mexico-
7299746) - 2015 - crc - 11/11/13
Climate Controls 8-7
0(Defrost):Press to clear the
windshield of fog or frost more
quickly. Air is directed to the
windshield and the side window
vents. The air conditioning
compressor also comes on, unless
the outside temperature is below
freezing.
Do not drive the vehicle until all
windows are clear.
See Air Vents on page 8-8.
A/C (Air Conditioning): Press to
turn the air conditioning system on
or off. An indicator light comes on to
show that the air conditioning is
enabled. If the fan is turned off, the
air conditioner will not run. The A/C
light will stay on even if the outside
temperatures are below freezing.
@(Recirculation): Press to turn
on recirculation. An indicator light
comes on. Air is recirculated to
quickly cool the inside of the
vehicle. It can also be used to help
reduce outside air and odors that enter the vehicle. The air
conditioning compressor also comes
on when this mode is activated.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
K(Rear Window Defogger):
Press to turn the rear window
defogger on or off. An indicator light
on the button comes on to show that
the rear window defogger is on.
The rear window defogger only
works when the ignition is in ON/
RUN. The rear window defogger
stays on for approximately
10 minutes after the button is first
pressed. Each subsequent press,
the rear window defogger stays on
for five minutes. The defogger also
turns off if the ignition is turned to
ACC/ACCESSORY or LOCK/OFF.
{Caution
Using a razor blade or sharp
object to clear the inside rear
window can damage the rear
window defogger. Repairs would
not be covered by the vehicle
warranty. Do not clear the inside
rear window with sharp objects.
Heated Mirror: If equipped with
heated outside rearview mirrors, the
mirrors heat to help clear fog or frost
from the surface of the mirror when
the rear window defog button is
pressed. See Heated Mirrors on
page 2-16.