GMC 2006 Sierra - Manual (Page 207)

Air Conditioning
#
(Air Conditioning): Press this button to turn the air
conditioning (A/C) compressor on and off. The snowflake
symbol will appear on the display when the A/C is on and
will turn off when the air conditioning is off.
Pressing this button when the outside temperature is too
cool for air conditioning will make the snowflake symbol
flash three times and then turn off to let you know the air
conditioning mode is not available. If the air conditioning
is on and the outside temperature drops below a
temperature which is too cool for air conditioning to be
effective, the snowflake symbol will turn off to let you
know the air conditioning mode has been canceled.
When air conditioning is selected or in AUTO mode, the
system will run the air conditioning automatically to cool
and dehumidify the air entering the vehicle. If you select
A/C off while in front defrost, defog or recirculation,
the A/C snowflake symbol will turn off, but the A/C
compressor will still run to help prevent fogging.
On hot days, open the windows long enough to let hot
inside air 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.
On cool, but sunny days while using manual operation of
the automatic system, use bi-level to deliver warm air to
the floor and cooler air to the instrument panel outlets. To
warm or cool the air delivered, turn the temperature knob
to the desired setting.
In AUTO mode the system will cool and dehumidify the
air inside the vehicle. Also while in AUTO mode, the
system will maximize its performance by using
recirculation as necessary.
Defogging and Defrosting
You can use either defog or front defrost to clear fog
or frost from your windshield. Use the defog mode
to clear the windows of fog or moisture. Use the
front defrost button to defrost the front windshield.
-
(Defog): Use this setting to clear the windows
of fog or moisture. Press the mode button to select
this setting. This setting will deliver air to the floor
and windshield outlets.
0
(Front Defrost): Press the front defrost button to
defrost the windshield. The system will automatically
control the fan speed if you select defrost from AUTO
mode. If the outside temperature is 40°F (4°C) or warmer,
your air conditioning compressor will automatically run to
help dehumidify the air and dry the windshield.
3-29