Page 257 of 518

Black plate (5,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-5
Driver and Passenger Side
Temperature Control
The driver and passenger side
temperature buttons are used to
adjust the temperature of the air
coming through the system on the
driver or passenger side of the
vehicle. The temperature can be
adjusted even if the system is
turned off. This is possible since
outside air always flows through the
system as the vehicle is moving
forward unless it is set to
recirculation mode. See
“Recirculation”later in this section.
Press the + or −buttons to increase
or decrease the cabin temperature.
The driver side or passenger side
temperature display shows the
temperature setting decreasing or
increasing. The passenger temperature setting
can be set to match the driver
temperature setting by pressing the
PASS button and turning off the
PASS indicator.
When in defrost mode the
passenger temperature setting
cannot be changed.
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 temperature(s) and
AUTO will be lit on the display.
The current delivery mode and
fan speed will also be displayed
for approximately 5 seconds. When AUTO is selected, the air
conditioning operation and air
inlet will be automatically
controlled. The air conditioning
compressor will run when the
outside temperature is over
about 4°C (40°F). The air inlet
will normally be set to outside
air. If it is hot outside, the air
inlet may automatically switch to
recirculate inside air to help
quickly cool down the vehicle.
The light on the button comes on
in recirculation.
2. Set the driver and passenger temperature.
To find your comfort setting, start
with a 23°C (74°F) temperature
setting and allow about
20 minutes for the system to
regulate. Use the driver or
passenger temperature buttons
to adjust the temperature setting
as necessary. If a temperature
setting of 15°C (60°F) is chosen,
Page 258 of 518

Black plate (6,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-6 Climate Controls
the system remains at the
maximum cooling setting. 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 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
D C(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.
H G(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.
Page 259 of 518

Black plate (7,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-7
-(Defog):This mode clears the
windows of fog or moisture. Air is
directed to the windshield, floor
outlets, and side window vents. In
this mode, the system turns off
recirculation and runs the air
conditioning compressor unless the
outside temperature is close to
freezing. The recirculation mode
cannot be selected while in the
defog mode.
0(Defrost): This mode removes
fog or frost from the windshield
more quickly. Air is directed to the
windshield and side window vents,
with some directed to the floor
vents. In this mode, the system
automatically forces outside air into
the vehicle and runs the air
conditioning compressor unless the
outside temperature is close to
freezing. The recirculation mode
cannot be selected while in the
defrost mode. The passenger temperature control
cannot be activated while in defrost
mode. If the PASS button is
pressed, the button indicator flashes
three times and will not work. If the
passenger temperature buttons are
adjusted, the driver temperature
indicator changes. The passenger
temperature will not be displayed.
If vent, bi-level, or floor mode is
selected again, the climate control
system displays the previous
temperature settings.
Do not drive the vehicle until all the
windows are clear.
#(Air Conditioning):
Press to
turn the air conditioning (A/C)
compressor on and off. An indicator
light comes on to show that the air
conditioning is on. If this button is pressed when the air
conditioning compressor is
unavailable, the indicator flashes
three times and then turns off. If the
air conditioning is on and the
outside temperature drops below a
temperature which is too cool for air
conditioning to be effective, the air
conditioning light turns off to show
that the air conditioning mode has
been canceled.
On hot days, open the windows long
enough to let hot inside air escape.
This helps to reduce the time it
takes for the vehicle to cool down.
It also helps the system to operate
more efficiently.
The air conditioning system
removes moisture from the air, so a
small amount of water might drip
under the vehicle while idling or
after turning off the engine. This is
normal.
Page 260 of 518

Black plate (8,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-8 Climate Controls
@(Recirculation):Press to turn
the recirculation mode on or off. An
indicator light comes on to show
that the recirculation is on.
This mode recirculates and helps to
quickly cool the air inside the
vehicle. It can be used to help
prevent outside air and odors from
entering the vehicle.
The recirculation mode cannot be
used with floor, defog, or defrost
modes. If recirculation is selected
with one of those modes, the
indicator light flashes three times
and then turns off. The air
conditioning compressor also comes
on when this mode is activated.
While in recirculation mode the
windows may fog when the weather
is cold and damp. To clear the fog,
select either the defog or defrost
mode and increase the fan speed.
The recirculation mode can also be
turned off by turning off the ignition. PASS:
Press to set the passenger
temperature setting to match the
driver temperature setting. The
PASS indicator will turn off. When
the passenger temperature setting
is set different than the driver
setting, the indicator on the PASS
button illuminates and both the
driver side and passenger side
temperature displays are shown.
REAR: For vehicles with the rear
heat and air conditioning controls.
Press to turn the rear climate control
system on or off. See Rear Climate
Control System (Rear Climate
Control Only) on page 8‑10 orRear
Climate Control System (Rear
Climate with Rear Seat Audio) on
page 8‑11.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
1(Rear Window Defogger):
Press to turn the rear window
defogger on or off. It automatically
turns off several minutes after it has
been activated. The defogger can
also be turned off by turning off the
engine. Do not drive the vehicle until
all the windows are clear.
Notice: Do not use a razor blade
or sharp object to clear the inside
rear window. Do not adhere
anything to the defogger grid
lines in the rear glass. These
actions may damage the rear
defogger. Repairs would not be
covered by your warranty.
Heated Mirrors: Press
1to help
clear fog or frost from the surface of
the outside mirror. See Power
Mirrors on page 2‑17.
Page 261 of 518

Black plate (9,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-9
Sensors
The solar sensor, located in the
defrost grille in the middle of the
instrument panel, monitors the solar
heat. Do not cover the solar sensor
or the system will not work properly.
The interior temperature sensors
located in the headliner above the
driver side seat and if equipped, in
the headliner above the second row
seats measure the temperature of
the air inside the vehicle.There is also an exterior
temperature sensor located behind
the front grille. This sensor reads
the outside air temperature and
helps maintain the temperature
inside the vehicle. Any cover on the
front of the vehicle could cause a
false reading in the displayed
temperature.
The climate control system uses the
information from these sensors to
maintain your comfort setting by
adjusting the outlet temperature, fan
speed, and the air delivery mode.
The system may also supply cooler
air to the side of the vehicle facing
the sun. The recirculation mode will
also be used as needed to maintain
cool outlet temperatures.
Page 262 of 518

Black plate (10,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-10 Climate Controls
Rear Climate Control System
(Rear Climate Control Only)
For vehicles with this system, the rear controls are three knobs located in
the headliner. The system can also be controlled with the front controls.
A. Fan Control
B. Temperature Control
C. Air Delivery Mode ControlREAR:
Press the REAR button on
the front climate control system to
turn the rear climate control system
on or off. An indicator comes on
when the rear system is on.
See Climate Control Systems on
page 8‑1 orDual Automatic Climate
Control System on page 8‑4. The rear system can also be turned
off by turning the rear fan knob to
the
9position.
Mimic Mode: This mode matches
the rear climate control to the front
climate control airflow settings.
It comes on when REAR is pressed
the first time.
Independent Mode: This mode
directs rear seating airflow
according to the settings of the rear
controls. It comes on when any rear
control is adjusted.
Temperature Control: Turn
clockwise or counterclockwise to
increase or decrease the airflow
temperature into the
passenger area.
Fan Control: Turn clockwise or
counterclockwise to increase or
decrease the fan speed.
Page 263 of 518

Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-11
Air Delivery Mode Control:Turn
clockwise or counterclockwise to
change the direction of the airflow.
H(Vent): Air is directed through
the headliner outlets.
)(Bi-Level): Air is directed
through the floor and headliner
outlets. The rear system floor
outlets are located directly behind
the second row seats. The flow can
be divided between vent and floor
outlets depending upon where the
knob is placed between the settings.
6(Floor): Air is directed to the
floor outlets. The rear system floor
outlets are located directly behind
the second row seats.
Rear Climate Control System
(Rear Climate with Rear Seat Audio)
For vehicles with the rear heat and air conditioning controls, they are
integrated with the rear seat audio controls located in the center console.
The system can be controlled from the front controls as well as the rear
controls.
Rear Climate Control with Rear Seat Audio Controls
A. Fan Control
B. Air Delivery Mode Control
C. Temperature Control REAR:
Press the REAR button on
the front climate control system to
turn the rear climate control system
on or off. An indicator comes on
when the rear system is on.
Page 264 of 518

Black plate (12,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-12 Climate Controls
The rear climate control system can
also be turned off by pressing and
holding the
Cbutton. To turn the
system on from the rear seats,
press any rear climate control
button, except the
Cbutton.
Mimic Mode: This mode matches
the rear climate control to the front
climate control airflow settings.
It comes on when REAR is pressed
the first time.
Independent Mode: This mode
directs rear seating airflow
according to the settings of the rear
controls.
To turn the system on from the rear,
press any rear climate control
button, except the
Cbutton.
Automatic Operation,
If Equipped
AUTO: Press the air delivery mode
button until this setting is selected to
control the inside temperature, air
delivery, and fan speed. AUTO
appears in the display when
automatic operation is active.
+ or −(Increase/Decrease
Temperature): Press the + or−
buttons to increase or decrease the
cabin temperature. The rear control
temperature display will show the
temperature setting increasing or
decreasing.
The display only indicates climate
control functions when the system is
in rear independent mode.
Manual Operation
D C(Fan Control): Press these
buttons on the rear seat audio
control panel to increase or
decrease the airflow. Pressing the
fan up button when the system is off
will turn the system on. The air
delivery mode will remain under
automatic control.
+ or −(Temperature Control):
Press these buttons to adjust the
temperature of the air flowing into
the passenger area. Press the +
button for warmer air and press the
− button for cooler air.
N(Air Delivery Mode Control):
Press the mode button to change
the direction of the airflow in the
vehicle. Repeatedly press the
button until the desired mode
appears on the display. Multiple
presses will cycle through the
delivery selections.