GMC 2008 Yukon Denali Owner's Manual page 187

O (On/Off): Press this button to turn off the climate
control system. Outside air will still enter the vehicle, and
will be directed to the floor. This direction can be
changed by pressing the mode button. Recirculation
can be selected once vent or bi-level mode has
been selected. 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 will illuminate briefly to show you
the settings and then return off. Press the on/off button
or the up down arrows on the fan switch, the defrost
button, AUTO button, or the air conditioning button
to turn the system on when it is off.
Manual Operation
You may manually adjust the air delivery mode or
fan speed.
y9 z
(Fan): The buttons with the fan symbols
allow you to manually adjust the fan speed. Press the
up arrow to increase fan speed and the down arrow
to decrease fan speed.
Pressing one of these buttons when the system is off
will turn the system on. Pressing one of these buttons
when in automatic control will place the fan under
manual control. The fan setting will remain displayed
and the AUTO light will turn off. The air delivery
mode will remain under automatic control.
yN z
(Mode): Press the mode up and down
buttons to manually change the direction of the airflow
in the vehicle. Repeatedly press the button until the
desired mode appears on the display. Pressing one of
these buttons when the system is off will change air
delivery mode without turning the system on. Pressing
one of these buttons when in automatic control will place
the mode under manual control.
The air delivery mode setting will be displayed and the
AUTO light will turn off. The fan will remain under
automatic control.
H
(Vent): This setting will deliver air to the instrument
panel outlets.
)
(Bi-Level): This mode directs half of the air to the
instrument panel outlets and half to the floor outlets.
The flow can be divided between vent and floor outlets
depending upon where the knob is placed between
the settings. A little air is directed towards the windshield
and side window outlets. Cooler air is directed to the
upper outlets and warmer air to the floor outlets.
6
(Floor): This mode directs most of the air to the
floor outlets, with some of the air directed to the
windshield, side window outlets, and second row floor
outlets. In this mode, the system automatically
selects outside air.
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