Automatic Operation - GMC 2008 Sierra 1500 Pickup Owner's Manual

Automatic Operation

AUTO (Automatic): When automatic operation is
active the system controls the inside temperature, the
air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display changes to
show the current temperature(s) and AUTO is lit on
the display. The current air delivery mode and
fan speed are also displayed for about 5 seconds.
When AUTO is selected, the air conditioning
operation and air inlet are automatically controlled.
The air conditioning compressor may run when
the outside temperature is above freezing. The air
inlet will normally be set to outside air. If it is
hot outside, the air inlet may automatically switch to
the recirculate mode to help quickly cool down
the air inside the vehicle. The light on the button
comes on in recirculation.
2. Set the driver's and passenger's temperature.
To find your comfort setting, start with a 74°F (23°C)
temperature setting and allow about 20 minutes
for the system to regulate. Use the driver's or
passenger's temperature buttons to adjust the
temperature setting as necessary. If you choose the
temperature setting of 60°F (15°C), the system
remains at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C), the
system remains at the maximum heat setting.
Choosing either maximum setting will not cause the
vehicle to heat or cool any faster.
Be careful not to cover the solar sensor located on the
top of the instrument panel near the windshield. This
sensor regulates air temperature based on sun load.
For more information on the solar sensor, see "Sensors"
later in this section.
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