GMC Yukon 2021 Owner's Manual page 210

Yukon/Yukon XL is shown, Denali similar
Move the slider knobs to change the
direction of the airflow. To close the vent
adjust slider knob away from you.
Rear System Air Vents
This vehicle has four round or rectangular
air vents in the headliner above the second
and third row seats.
Press on the center vane rear edge to open
the round outlet. Use the center vane to
rotate the outlet and change the direction
of the airflow. Press on the center vane
leading edge to shut off the air flow.
Move the slider knob on rectangular vents
and rotate the outlet barrel left to right to
change the direction of the air flow and to
shut off the air flow.
Operation Tips
Clear away any ice, snow, or leaves from
the 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.
When you enter a vehicle in cold
weather, press the fan up button to the
maximum fan level before driving. This
helps clear the intake ducts of snow and
moisture, and reduces the chance of
fogging the inside of the window.
Climate Controls
Keep the air 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.
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 0 384. To find out
what type of filter to use, see Maintenance
Replacement Parts 0 394.
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