Buick 2009 Lucerne - Manual (Page 167)

Automatic Operation
AUTO (Automatic Fan): When AUTO is selected on
the fan control, the system automatically adjusts the fan
speed. If the OnStar
® system is activated when this
position is selected, the fan speed will lower.
AUTO (Automatic Mode)
1. Turn the fan control to AUTO.
2. Turn the mode control to AUTO.
3. Adjust the temperature to a comfortable setting
between 68°F (21°C) and 78°F (26°C).
Choosing the coldest or warmest temperature setting
will not cause the system to heat or cool any faster.
In cold weather, the system starts at reduced fan
speeds to avoid blowing cold air into the vehicle until
warmer air is available. The system will start out
blowing air to the floor, but may change modes
automatically as the vehicle warms up to maintain the
chosen temperature setting. The length of time
needed to warm the interior depends on the outside
temperature.
4. Wait a few minutes for the system to automatically
regulate. Then adjust the temperature as necessary
to find your comfort setting.
Do not cover the solar sensor located in the center of
the instrument panel, near the windshield. For more
information on the solar sensor, see “Sensors” later in
this section.
After the vehicle is started, the display shows the
interior temperature settings.
When the ENG/MET (English/metric) button on the
Driver Information Center (DIC) is pressed, the display
shows readings in Fahrenheit or Celsius. Use the
ENG/MET button to toggle between the readings.
AUTO (Automatic Air Conditioning): If AUTO is
selected on the fan or mode control, the system
automatically controls the air conditioning compressor.
The A/C compressor runs automatically even at cool
outside temperatures in order to dehumidify the air.
The A/C indicator light is lit when the system is operating
automatically. Press the A/C button on the fan control
to turn off the A/C. To clear windows better in defog
or defrost modes, the A/C compressor runs
automatically in damp cool conditions.
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