2021 GMC SIERRA Climate

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Infotainment System 191
.Set Number of Audio Favorites: Touch to
select how many favorites pages can be
viewed from the audio application. The
Auto setting will automatically adjust this
number based on the number of favorites
you have saved. Touch Auto, 5, 10, 15, 20,
25, 30, 35, or 40.
.RDS: This allows the Radio Data System
(RDS) to be turned on or off.
Touch the controls on the infotainment
display to disable or enable.
.HD Radio: This allows HD Radio reception
to be turned on or off.
Touch the controls on the infotainment
display to disable or enable.
.Explicit Content Filter: This setting allows
access to explicit content SiriusXM
channels.
Touch Off or On.
.Manage Phones: Select to connect to a
different phone source, disconnect a
phone, or delete a phone.
.Reset Music Index: This allows the music
index to be reset if you are having
difficulty accessing all of the media
content on your device.
Touch Yes or No.Climate
Touch and the following may display:
.Auto Fan Speed: This setting specifies the
amount of airflow when the climate
control fan setting is Auto Fan.
Touch Low, Medium, or High.
.Air Quality Sensor: This setting switches
the system into Recirculation Mode based
on the quality of the outside air.
Touch Off, Low Sensitivity, or High
Sensitivity.
.Auto Cooled Seats: This setting
automatically turns on and regulates the
ventilated seats when the cabin
temperature is warm.
Touch the controls on the infotainment
display to disable or enable.
.Auto Heated Seats: This setting
automatically turns on and regulates the
heated seats when the cabin temperature
is cool. The auto heated seats can be
turned off by using the heated seat
controls on the center stack.
Touch the controls on the infotainment
display to disable or enable.
.Auto Defog: This setting automatically
turns the front defogger on when the
vehicle engine is started. Touch the controls on the infotainment
display to disable or enable.
.Auto Rear Defog: This setting
automatically turns the rear window
defogger on when the vehicle engine is
started.
Touch the controls on the infotainment
display to disable or enable.
Navigation
Touch and the following may display:
.Set Up My Places
.Map Preferences
.Route Preferences
.Navigation Voice Control
.Traffic Preferences
.Alert Preferences
.Manage History
.Predictive Navigation
.About
See Using the Navigation System 0163.
Phone
Touch and the following may display:
.My Number: Displays the cell phone
number of the Bluetooth connected
device.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
204 Climate Controls
Climate Controls
Climate Control Systems
Climate Control Systems . . . . . . . . . . . . . . 204
Dual Automatic Climate ControlSystem . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206
Air Vents
Air Vents . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 209
Maintenance
Passenger Compartment Air Filter . . . . . 209
Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210
Climate Control Systems
The heating, cooling, and ventilation in the vehicle can be controlled with this system.
1. Fan Control
2. MAX Defrost
3. Air Delivery Mode Controls
4. A/C (Air Conditioning)
5. TEMP (Temperature Control)
6. Recirculation
7. Rear Window Defogger (If Equipped) or Heated Mirrors (If Equipped)9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Turn the
knob all the way counterclockwise to turn
the fan off.
TEMP : Turn clockwise or counterclockwise
to increase or decrease the temperature
inside the vehicle.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Climate Controls 205
Air Delivery Mode Controls :Pressz,Y,
or
[to change the direction of the
airflow. Any combination of the three
controls can be selected. An indicator light
comes on in the selected mode button.
To change the current mode, select one or
more of the following. An indicator light will
illuminate:
z: Air is directed to the windshield,
outboard a/c outlets, and side window
outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor outlets,
with some air directed to the windshield,
outboard a/c outlets, and side window
outlets.
0MAX : Air is directed to the windshield
and the fan runs at a higher speed if not
already above a medium fan speed. This
mode overrides the previous mode selected
and clears fog or frost from the windshield
more quickly. When the control is pressed
again, the system returns to the previous
mode setting and fan speed. For best results, clear all snow and ice from
the windshield before defrosting.
@:
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.
Avoid using recirculation for long periods of
time in cold or damp conditions. Using
recirculation in cold or damp conditions can
result in window fogging.
A/C : Press to turn the air conditioning 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
1REAR : 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 engine is running. The defogger turns
off if the ignition is turned off or to
ACC/ACCESSORY.
If equipped with heated outside mirrors,
press
fto turn them on or off. See Heated
Mirrors 037.
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.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
206 Climate Controls
Dual Automatic Climate Control System
The heating, cooling, and ventilation in the vehicle can be controlled with this system.
1. Driver and Passenger TemperatureControls
2. MAX Defrost
3. Air Delivery Mode Controls
4. A/C (Air Conditioning)
5. SYNC (Synchronized Temperature) 6. Recirculation
7. Power Button
8. Fan Control
9. Rear Window Defogger (If Equipped) or
Heated Mirrors (If Equipped)
10. AUTO (Automatic Operation)
Climate Control Display
1. Driver and Passenger Temperature Settings
2. Fan Control
3. Driver and Passenger Temperature Controls
4. Sync (Synchronized Temperature)
5. Recirculation
6. Air Delivery Mode Controls
7. Auto (Automatic Operation)
8. A/C (Air Conditioning)
9. On/Off (Power)

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Climate Controls 207
The fan, air delivery mode, air conditioning,
driver and passenger temperatures, and Sync
settings can be controlled by touching
CLIMATE on the infotainment Home Page or
the climate button in the climate control
display application tray. A selection can then
be made on the front climate control page
displayed.
Climate Control Status Display
The climate control status display appears
briefly when the center stack climate
controls are adjusted.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 AUTO is lit, all four functions operate
automatically. Each function can also be
manually set and the selected setting is
displayed. Functions not manually set will
continue to be automatically controlled,
even if the AUTO indicator is not lit.
For automatic operation:
1. Press AUTO.
2. Set the temperature. Allow the system time to stabilize. 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.
The recirculation light will not come on
when automatically controlled. See@
under “Manual Operation” for more details.
Manual Operation
9:Turn clockwise or counterclockwise to
increase or decrease the fan speed. Press the
knob to turn the fan off. When off is selected, a small amount of air may still
come out of the outlets depending on
vehicle speed. If any buttons are pressed or
knobs are turned, the climate control system
will turn on and operate at the current
setting.
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. The driver
side or passenger side temperature display
shows the temperature setting increasing or
decreasing.
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 will turn off.
Air Delivery Mode Control : Press
z,Y,
or
[to change the direction of the
airflow. Any combination of the three
controls can be selected. An indicator light
comes on in the selected mode button.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
208 Climate Controls
Changing the mode cancels the automatic
operation and the system goes into manual
mode. Press AUTO to return to automatic
operation.
To change the current mode, select one or
more of the following:
z:Air is directed to the windshield,
outboard a/c outlets, and side window
outlets.
Y: Air is directed to the a/c outlets.
[:Air is directed to the floor outlets,
with some air directed to the windshield,
outboard a/c outlets, and side window
outlets.
0MAX : Air is directed to the windshield
and the fan runs at a higher speed if not
already above a medium fan speed. This
mode overrides the previous mode selected
and clears fog or frost from the windshield
more quickly. When the control is pressed
again, the system returns to the previous
mode setting and fan speed.
For best results, clear all snow and ice from
the windshield before defrosting.
@: 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.
Avoid using recirculation for long periods of
time in cold or damp conditions. Using
recirculation in cold or damp conditions can
result in window fogging.
A/C : Press to turn the air conditioning 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
1REAR : 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 engine is running. The defogger turns
off if the ignition is turned off or to ACC/
ACCESSORY.
If equipped with heated outside mirrors,
press
fto turn them on or off. See Heated
Mirrors 037.
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.
Remote Start Climate Control Operation :
If equipped with remote start, the climate
control system may run when the vehicle is
started remotely. If equipped with heated or
ventilated seats or a heated steering wheel,
these features may come on during a
remote start. See Remote Vehicle Start 020,
Heated and Ventilated Front Seats 052, and
Heated Steering Wheel 0100.
Sensors

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
Climate Controls 209
The solar sensor, on top of the instrument
panel near the windshield, monitors the
solar heat.
The climate control system uses the sensor
information to adjust the temperature, fan
speed, recirculation, and air delivery mode
for best comfort.
Do not cover the sensor; otherwise the
automatic climate control system may not
work properly.
Air Vents
Use the sliding knobs on the center and side
air vents to change the direction of 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.
To close the front a/c vents, move the
sliding knobs to the full down position.
To close the rear a/c vents, move the sliding
knobs to the full inboard position.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.
.Do not attach any devices to the air vent
slats. This will restrict airflow and may
cause damage to the air vents.
Maintenance
Passenger Compartment Air Filter
The filter reduces the dust, pollen, and other
airborne irritants from outside air that is
pulled into the vehicle.
The filter should be replaced as part of
routine scheduled maintenance. See
Maintenance Schedule
0409. To find out
what type of filter to use, see Maintenance
Replacement Parts 0419.
1. Open the lower glove box door
completely.

GMC Sierra/Sierra Denali 1500 Owner Manual (GMNA-Localizing-U.S./
Canada/Mexico-14632426) - 2021 - CRC - 11/5/20
210 Climate Controls
2. Push the dampener arm to the left untilit releases the glovebox.
3. Press the sides of the glove box doorinward and rotate the door downward to
remove.
4. Pull lever on left side of the filter doorand slide left, then remove the door.
Remove the old filter.
5. Install the new air filter.
6. Reinstall the filter door.
7. Reverse the steps to reinstall the glove box.
See your dealer if additional assistance is
needed.
Service
All vehicles have a label underhood that
identifies the refrigerant used in the vehicle.
The refrigerant system should only be
serviced by trained and certified technicians.
The air conditioning evaporator should never
be repaired or replaced by one from a
salvage vehicle. It should only be replaced
by a new evaporator to ensure proper and
safe operation.
During service, all refrigerants should be
reclaimed with proper equipment. Venting
refrigerants directly to the atmosphere is
harmful to the environment and may also
create unsafe conditions based on
inhalation, combustion, frostbite, or other
health-based concerns.
The air conditioning system requires periodic
maintenance. See Maintenance Schedule
0 409.