Buick 2008 Lucerne Owner's Manual page 165

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(Outside Air): This mode lets outside air enter
the vehicle. When the button is pressed, an indicator
light turns on. Pressing the recirculation button cancels
this mode.
?
(Recirculation): Press this button to recirculate
cabin air through the vehicle. An indicator light below the
button comes on to show that this mode is activated.
This mode can be used to prevent outside air and odors
from entering the vehicle or to help cool the air inside
the vehicle more quickly. This mode cannot be selected
while in the defog or defrost modes. If you try to
select the recirculation mode, the indicator light flashes
three times and turns off.
Operation in this mode during periods of high humidity
and cool outside temperatures may result in increased
window fogging. If window fogging is experienced, select
the defrost mode.
wx
(Driver Temperature Controls): Press these
buttons next to the fan control to manually increase or
decrease the temperature inside the vehicle.
wx
(Passenger Temperature Controls): Press
these buttons next to the mode control to manually
increase or decrease the temperature for the front
passenger. If the passenger climate control system is
off, pressing one of these buttons turns it on.
PASS (Passenger Climate Control): Press this button
to turn the passenger climate control systems on or off.
When the passenger climate control system is on, the
passenger temperature setting is displayed.
If the PASS button is pressed to turn the passenger
temperature setting off, the driver temperature setting
controls the temperature for the entire vehicle.
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