GMC 2010 Sierra 1500 Crew Cab Owner's Manual page 247

The heating, cooling, and ventilation in the vehicle can
be controlled with this system. The vehicle also has a
flow-through ventilation system described later in this
section.
A. Driver and Passenger
Temperature Controls
B. Fan Control
C. AUTO
D. Defrost
E. Recirculation
F. Outside Air
G. Air Delivery Mode
Control
H. Display
I. Power Button
Press to turn the climate control system on
or off. Outside air still enters the vehicle, and is directed
to the floor. This direction can be changed by pressing
the mode button. Recirculation can be selected once
you have selected vent or bi-level mode. The
temperature can also be adjusted using either
temperature button. If the air delivery mode or
temperature settings are adjusted with the system off,
the display illuminates briefly to show the settings and
then returns to off. The system can be turned back on
by pressing either , , ,
button.
J. Rear Window
Defogger
K. Air Conditioning
L. PASS (Passenger)
, the defrost or the AUTO
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