GMC Yukon 2011 Owner's Manual page 272

8-6 Climate Controls
If a temperature setting
of 32°C (90°F) is chosen, the
system remains at the maximum
heat setting. Choosing either
maximum setting will not cause
the vehicle to heat or cool any
faster.
Do not to cover the solar sensor
located on the top of the instrument
panel near the windshield. This
sensor regulates air temperature
based on sun load and also turns
on the headlamps. For more
information on the solar sensor,
see Sensors later in this section.
To avoid blowing cold air in cold
weather, the system will delay
turning on the fan until warm air
is available. The length of delay
depends on the engine coolant
temperature. Pressing the fan
switch will override this delay and
change the fan to a selected speed.
Manual Operation
(Fan Control): Press these
buttons to increase or decrease the
fan speed.
Pressing either fan button while in
automatic control places the fan
under manual control. The fan
setting remains displayed and
the AUTO light turns off. The air
delivery mode remains under
automatic control.
(Air Delivery Mode Control):
Press these buttons to change the
direction of the airflow in the vehicle.
Repeatedly press either button until
the desired mode appears on the
display. Pressing either mode button
while the system is off changes the
air delivery mode without turning the
system on. Pressing either mode
button while in automatic control
places the mode under manual
control.
The air delivery mode setting is
displayed and the AUTO light
turns off. The fan remains under
automatic control.
H
(Vent): Air is directed to the
instrument panel outlets.
)
(Bi-Level): Air is divided
between the instrument panel and
floor outlets. Some air is directed
towards the windshield and side
window outlets.
6
(Floor): Air is directed to the
floor outlets, with some to the
windshield, side window outlets,
and second row floor outlets. In this
mode, the system automatically
selects outside air.