2018 GMC SIERRA DENALI Owners Manual

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
224 Climate Controls
Climate Controls Climate Control Systems Climate Control Systems (with
Heater Only) . . . . . . . . . . . . . . . . 224
Climate Control Systems (with
Air Conditioning) . . . . . . . . . . . . 226
Dual Automatic Climate
Control System . . . . . . . . . . . . . 228
Air Vents Air Vents . . . . . . . . . . . . . . . . . . . . . 231
Maintenance Passenger Compartment Air
Filter . . . . . . . . . . . . . . . . . . . . . . . . 232
Service . . . . . . . . . . . . . . . . . . . . . . . 233 Climate Control Systems Climate Control Systems (with Heater Only) With this system, the heating and ventilation can be controlled.
1. Fan Control
2. Air Recirculation
3. Air Delivery Mode Controls
4. Defrost
5. TEMP (Temperature Control) TEMP : Turn clockwise or
counterclockwise to increase or
decrease the temperature inside the
vehicle.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 225
9 : 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 Controls :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets. [ : Air is directed to the floor
outlets, with some air directed to the
windshield, side window, and
second row floor outlets.
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The system
automatically forces outside air into
the vehicle. Do not drive the vehicle until all the
windows are clear.
See Air Vents 0 231 .
@ : 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
226 Climate Controls
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 Controls
4. Defrost
5. TEMP (Temperature Control) 6.
K (Rear Window Defogger, If
Equipped)
f (Outside Heated Mirror, If
Equipped)
8 (Outside Air, If Equipped)
7.
@ Air Recirculation TEMP : Turn clockwise or
counterclockwise to increase or
decrease the temperature inside the
vehicle.
9 : 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 Controls :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets.
[ : Air is directed to the floor
outlets, with some air directed to the
windshield and side window outlets.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 227
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
side window vents.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the 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.
See Air Vents 0 231 .
@ : 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 : If equipped, press to turn the
outside air mode on. An indicator
light on the button comes on to
show that outside air is on. When
selected, air from outside the
vehicle circulates throughout the
vehicle. The recirculation mode
cannot be used with the outside
air mode.
A/C : 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 : 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 on. The
defogger turns off if the ignition is
turned to ACC/ACCESSORY or 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.
CautionUsing 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.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
228 Climate Controls
Dual Automatic Climate Control System With this system the heating, cooling, and ventilation in the vehicle can be
controlled.
For an eAssist vehicle, see the Silverado/Sierra eAssist supplement.
1. Driver Temperature Control
2. A/C (Air Conditioning)
3. Air Delivery Mode Controls
4. Fan Control
5. Defrost
6. Passenger Temperature
Control 7. SYNC (Synchronized
Temperature)
8. Rear Window Defogger
9. Power Button
10. Air Recirculation
11. AUTO (Automatic Operation) Automatic Operation
The system automatically controls
the fan speed, air delivery, air
conditioning, and recirculation in
order to heat or cool the vehicle to
the desired temperature.
When the indicator light is on, the
system is in full automatic operation.
If the air delivery mode or fan
setting is manually adjusted, the
auto indicator turns off and displays
will show the selected settings.
To place the system in
automatic mode:
1. Press AUTO.
2. Set the driver and passenger
temperature.
To find your comfort setting,
start with 22 °C (72 °F) and
allow the system time to
stabilize. Then adjust the
temperature as needed for best
comfort.
To improve fuel efficiency and to
cool the vehicle faster, recirculation
may be automatically selected in
warm weather.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 229The recirculation light will not come
on when automatically controlled.
Press
@ to manually select
recirculation; press it again to select
outside air.
Do not cover the solar sensor on the
top of the instrument panel near the
windshield. This sensor regulates
air temperature based on sun load.
See “ Sensors ” later in this section.
Manual Operation
O : Press to turn the climate control
system on or off. Outside air still
enters the vehicle, and is directed to
the floor. This direction can be
changed by pressing the air
delivery mode.
9 : Turn clockwise or
counterclockwise to increase or
decrease the fan speed. Press the
knob to turn the fan off.
Press AUTO to return to automatic
operation. Driver and Passenger
Temperature Control : The
temperature can be adjusted
separately for the driver and
passenger.
Turn the knob clockwise or
counterclockwise to increase or
decrease the driver or passenger
temperature setting.
SYNC : Press to link the passenger
temperature setting to the driver
setting. The SYNC indicator light will
turn on. When the passenger setting
is adjusted, the SYNC indicator light
is off.
The driver side or passenger side
temperature display shows the
temperature setting increasing or
decreasing.
Air Delivery Mode Control :
Press
Y ,
\ ,
[ , or
- to change
the direction of the airflow. An
indicator light comes on in the
selected mode button. Changing the mode cancels the
automatic operation and the system
goes into manual mode. Press
AUTO to return to automatic
operation.
Y : Air is directed to the instrument
panel outlets.
\ : Air is divided between the
instrument panel and floor outlets.
Some air is directed toward the
windshield and side window outlets.
[ : Air is directed to the floor
outlets, with some to the windshield,
side window outlets, and second
row floor outlets.
- : This mode clears the windows
of fog or moisture. Air is directed to
the windshield, floor outlets, and
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.
0 : Press to clear the windshield
of fog or frost more quickly. Air is
directed to the windshield and the
side window vents. The air

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
230 Climate Controls 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 0 231 .
A/C : 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.
@ : 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 : 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 defogger turns off if the
ignition is turned to ACC/
ACCESSORY or LOCK/OFF.
CautionUsing 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,
press
K to heat the mirrors. See
Heated Mirrors 0 50 . Sensors
The solar sensor, located in the
defrost grille in the middle of the
instrument panel, monitors the solar
heat. Do not cover the solar sensor
or the system will not work properly.
There is also an exterior
temperature sensor behind the front
grille. This sensor reads the outside
air temperature and helps maintain
the temperature inside the vehicle.
Any cover on the front of the vehicle
including a snow plow, could cause
a false reading in the displayed
temperature.
Some vehicles may have the
exterior temperature sensor in the
passenger side mirror instead of the
front grille area.

GMC Sierra/Sierra Denali Owner Manual (GMNA-Localizing-U.S./Canada/
Mexico-11349177) - 2018 - CRC - 10/17/17
Climate Controls 231The climate control system uses the
information from these sensors to
maintain comfort settings by
adjusting the outlet temperature, fan
speed, and the air delivery mode.
The system may also supply cooler
air to the side of the vehicle facing
the sun. The recirculation mode will
also be used as needed to maintain
cool outlet temperatures.
Air Vents Use the sliding knobs on the center
and side air vents to direct the
airflow. Use the thumbwheels near
the air vents to open or close off the
airflow.
Air vents blow warm air on the side
windows in cold weather. If Floor,
Defog, or Defrost modes are
selected, a small amount of air will
come from the vents close to the
window. If the airflow is shut off
using the thumbwheels, warm air
will be directed to the other
instrument panel vents. This is
normal operation.
Use the thumbwheels to turn vent
airflow on or off based on the mode
selected. Operation Tips
.
Clear away any ice, snow,
or leaves from air inlets at the
base of the windshield that could
block the flow of air into the
vehicle.
.
Clear snow off the hood to
improve visibility and help
decrease moisture drawn into
the vehicle.
.
Keep the path under the front
seats clear of objects to help
circulate the air inside of the
vehicle more effectively.
.
Use of non-GM approved hood
deflectors can adversely affect
the performance of the system.
Check with your dealer before
adding equipment to the outside
of the vehicle.