Air Conditioning; Heating - GMC 2002 Yukon Denali Owner's Manual

Air Conditioning

On hot days, open the windows long enough to let hot
air inside escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
The A/C button, located below the mode knob, allows
the air coming into your vehicle to be cooled. This
setting is useful for normal cooling on hot days.
Use A/C with recirculation on to allow the air inside
your vehicle to be recirculated. This setting will help to
maximize your air conditioner's performance and your
vehicle's fuel economy. This setting also cools the air
the fastest and can be used to keep unwanted odors
and/or dust from entering the vehicle.
When using the air conditioner, turn off the recirculation
setting and use the outside air setting after the vehicle
reaches a comfortable interior temperature. When the
right knob on the control panel is between floor and
defrost, the recirculation feature will not function.
This helps reduce window fogging.
3-8
Passenger Compartment Air Filter
Your vehicle is equipped with a passenger compartment
air filter which filters outside air entering the vehicle.
For information on replacing the filter see "Passenger
Compartment Air Filter" in the Index.

Heating

The heater works best if you keep your windows closed
while using it. On cold days, use the floor or bi
(mode knob set between vent and floor) setting with the
temperature knob in the red area.
On cold days, approximately 32 _ F (
you may experience differences in how the transmission
shifts until the engine is warm. This feature
automatically reduces the time it takes for the engine to
reach normal operating temperature and shortens the
time it takes the heater to reach full output.
If you use the engine coolant heater before starting your
engine in cold weather, 20 _ F (
heating system will produce warmer air faster to heat the
passenger compartment.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature. For more information, see "Engine Coolant
Heater" in the Index.
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level
0 _ C) or lower,
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8 _ C) or lower, the
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