Cadillac 2007 XLR Owner's Manual page 182

There is also a sensor located behind the front
bumper. This sensor reads the outside air
temperature and helps maintain the temperature
inside the vehicle. The outside temperature will be
displayed in the navigation system only when
the engine is running. Any cover on the front of the
vehicle could give a false reading of the
temperature.
If the outside temperature goes up, the display
temperature will not change until:
•
The vehicle's speed is above 15 mph
(24 km/h) for five minutes.
•
The vehicle's speed is above 32 mph
(51 km/h) for two and one-half minutes.
These delays prevent false readings. If the
temperature goes down, the outside temperature
will be shown when you start the vehicle. If it
has been turned off for less than three hours, the
temperature will be recalled from the previous
vehicle operation.
There is also an inside temperature sensor
located to the left of the ignition button. The
automatic climate control system uses this sensor
to receive information, so if you block or cover
it, the system will not function properly.
182
Defogging and Defrosting
Fog on the inside of windows is a result of high
humidity (moisture) condensing on the cool window
glass. This can be minimized if the climate control
system is used properly. There are two modes to
clear fog or frost from your windshield. Use the
floor/defog mode to clear the windows of fog or
moisture and warm the passengers. Use defrost to
remove fog or frost from the windshield more
quickly.
-
(Floor/Defog): Press the mode button until the
defog mode appears on the display. This mode
directs the air between the windshield, floor outlets
and side windows. When you select this mode,
the system turns off recirculation and runs the air
conditioning compressor unless the outside
temperature is near or below freezing.
1
(Defrost): Press this button to direct most of
the air to the windshield, with some air directed
to the side windows. In this mode, the system will
automatically turn off the recirculation and run
the air conditioning compressor, unless the outside
temperature is near or below freezing. Do not
drive the vehicle until all the windows are clear.