Buick LaCrosse Owner's Manual page 199

When the indicator light is on, air is
recirculated inside the vehicle. If the
indicator light is off, outside air will
flow into the vehicle. Press AUTO or
to return to automatic
operation.
The climate control
system may have a sensor to
automatically detect high humidity
inside the vehicle. When high
humidity is detected, the climate
control system may adjust to
outside air supply and turn on the
air conditioner. The fan speed may
slightly increase to help prevent
fogging. If the climate control
system does not detect possible
window fogging, it returns to normal
operation. For eAssist vehicles,
there may be shorter and less
frequent auto stops when auto
defog is in use.
To turn Auto Defog off or on, see
Climate and Air Quality under
.
Press to turn the rear window
defogger on or off.
The rear window defogger turns off
automatically after about
10 minutes. If turned on again it
runs for about five minutes before
turning off. The defogger can also
be turned off by turning the ignition
to ACC/ACCESSORY or
LOCK/OFF.
The rear window defogger can be
set to automatic operation. See
Climate and Air Quality under
. When auto rear defog is
selected, the rear window defogger
turns on automatically when the
interior temperature is cold and the
outside temperature is about 4°C
(40°F) and below. The auto rear
defogger turns off automatically
after about 10 minutes, or after
five minutes if the outside
temperature is not as cold.
For eAssist vehicles, auto rear
defog will only run during a remote
start and the feature is not available
in the Vehicle Personalization menu.
For vehicles with heated outside
rearview mirrors, they turn on when
the rear window defogger button is
on and help to clear fog or frost from
the surface of the mirror. See
vehicles with this feature, press to
turn on or off. See
.
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For