Buick Lucerne 2007 Owner's Manual page 191

Sensors
The solar sensor, located in the defrost grille,
middle of the instrument panel, monitors the solar
radiation. Do not cover the solar sensor or the
system will not work properly.
There is also an interior temperature sensor
located next to the steering wheel that measures
the temperature of the air inside your vehicle.
There is also an exterior temperature sensor
located behind the front grille. This sensor reads
the outside air temperature and helps maintain the
temperature inside the vehicle. Any cover on
the front of the vehicle could cause a false reading
in the displayed temperature.
In order to prevent false temperature readings at
startup, the displayed temperature will not
change until the following occurs:
•
Vehicle speed is above 10 mph (16 k/mh) for
5 minutes.
•
Vehicle speed is above 32 mph (51 k/mh) for
2 and a half minutes.
The climate control system uses the information
from these sensors to maintain your comfort setting
by adjusting the outlet temperature, fan speed, and
the air delivery mode. The system may also supply
cooler air to the side of the vehicle facing the sun.
The recirculation mode will also be used as needed
to maintain cool outlet temperatures.
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