GMC Yukon Denali 2006 Manual page 167

Driver's Side Temperature Knob
The driver's side knob is used to adjust the temperature
of the air coming through the system on the driver's
side. The temperature can be adjusted even if the
system is turned off. This is possible since outside air
will always flow through the system as the vehicle
is moving forward unless it is set to recirculation mode.
See "Recirculation" later in this section.
Turn the knob counterclockwise or clockwise to lower or
increase the cabin temperature. The display will show
the temperature setting decreasing or increasing and an
arrow pointing to the driver will be displayed under
and to the left of the temperature setting.
Passenger's Side Temperature Knob
The passenger's side knob can be used to change the
temperature of the air coming through the system
on the passenger's side of the vehicle. The temperature
can be adjusted even if the system is turned off. This
is possible since outside air will always flow through the
system as the vehicle is moving forward unless it is
set to recirculation mode. See "Recirculation" later in
this section.
Turn the knob counterclockwise or clockwise to lower or
increase the cabin temperature. The display will show
the temperature setting decreasing or increasing and an
arrow pointing to the passenger will be displayed
under and to the right of the temperature setting.
The passenger's temperature setting can be set to
match the driver's temperature setting by pressing and
holding the AUTO button for four seconds. Both the
driver and passenger arrows will be displayed.
Automatic Operation
AUTO (Automatic): When automatic operation is
active the system will control the inside temperature, the
air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display will change to
show the current driver's set temperature, delivery
mode and fan speed. Press the AUTO button again
within five seconds to display the passenger's set
temperature.
If the driver's and passenger's temperature settings
are the same when AUTO is pressed, the
temperature setting and both arrows will be displayed
for five seconds along with the automatic air delivery
mode and fan speed. After the five-second update,
the display will change to show the temperature
setting, both arrows and AUTO.
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