2012 GMC YUKON light

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual - 2012
8-2 Climate Controls
9(Fan Control):Turn the left
knob clockwise or counterclockwise
to increase or decrease the fan
speed. Turn the knob all the way
counterclockwise to turn the front
system off.
Air Delivery Mode Control: Turn
clockwise or counterclockwise to
change the airflow direction inside
the vehicle. By positioning the knob
between two modes, a combination
of those modes is selected.
Select from the following modes:
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. Cooler air is
directed to the upper outlets and
warmer air to the floor outlets.
6(Floor): Air is directed to the
floor outlets, with some of the air
directed to the windshield, side window, and second row floor
outlets. In this mode, the system
automatically selects outside air.
Recirculation cannot be selected
when in Floor Mode.
-(Defog):
The defog mode is
used to clear 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): The defrost mode is
used to remove 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. The recirculation
mode cannot be selected while
in the defrost mode. The air
conditioning compressor runs automatically in this setting, unless
the outside temperature is close to
freezing.
Do not drive the vehicle until all the
windows are clear.
#(Air Conditioning):
Press this
button to turn the air conditioning
system on or off. An indicator light
comes on to show that the air
conditioning is on. The air
conditioning can be selected in
any mode as long as the fan
switch is on.
On hot days, open the windows to
let hot inside air escape; then close
them. 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.

Black plate (3,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-3
h(Recirculation):Press this
button to turn the recirculation mode
on or off. An indicator light comes
on to show that 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, defrost, or defogging
modes. If recirculation is selected
while in one of those modes, the
indicator flashes three times and
turns off. The air conditioning
compressor will also come 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 engine. REAR:
Press to turn the rear
heating and air conditioning on. See
Rear Climate Control System (Rear
Climate Control Only) on page 8‑10
or Rear Climate Control System
(Rear Climate with Rear Seat Audio)
on page 8‑11 for more information.
Rear Window Defogger
The rear window defogger uses a
warming grid to remove fog from the
rear window.
1(Rear Window Defogger):
Press this button to turn the rear
window defogger on or off. The
system 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. For vehicles with heated outside
rearview mirrors, the mirrors will
heat to help clear fog or frost from
the surface of the mirror when the
rear window defog button is
pressed.
Notice:
Do not use anything
sharp on the inside of the rear
window. If you do, you could cut
or damage the warming grid, and
the repairs would not be covered
by the vehicle warranty. Do not
attach a temporary vehicle
license, tape, a decal, or anything
similar to the defogger grid.

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,

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.

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.

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.

Black plate (8,1)GMC Yukon/Yukon XL Owner Manual - 2012
9-8 Driving and Operating
When driving on hills:
.Use a low gear and keep a firm
grip on the steering wheel.
.Maintain a slow speed.
.When possible, drive straight up
or down the hill.
.Slow down when approaching
the top of the hill.
.Use headlamps even during the
day to make the vehicle more
visible.
{WARNING
Driving to the top of a hill at high
speed can cause an accident.
There could be a drop-off,
embankment, cliff, or even
another vehicle. You could be
seriously injured or killed. As you
near the top of a hill, slow down
and stay alert.
.Never go downhill forward or
backward with either the
transmission or transfer case in
N (Neutral). The brakes could
overheat and you could lose
control.
{WARNING
If the vehicle has the two‐speed
automatic transfer case, shifting
the transfer case to N (Neutral)
can cause your vehicle to roll
even if the transmission is in
P (Park). This is because the
N (Neutral) position on the
transfer case overrides the
transmission. You or someone
else could be injured. If leaving
the vehicle, set the parking brake
and shift the transmission to
P (Park). Shift the transfer case to
any position but N (Neutral).
.When driving down a hill, keep
the vehicle headed straight
down. Use a low gear because
the engine will work with the
brakes to slow the vehicle and
help keep the vehicle under
control.
{WARNING
Heavy braking when going down
a hill can cause your brakes to
overheat and fade. This could
cause loss of control and you or
others could be injured or killed.
Apply the brakes lightly when
descending a hill and use a low
gear to keep vehicle speed under
control.
If the vehicle stalls on a hill:
1. Apply the brakes to stop the vehicle, and then apply the
parking brake.

Black plate (11,1)GMC Yukon/Yukon XL Owner Manual - 2012
Driving and Operating 9-11
After Off-Road Driving
Remove any brush or debris that
has collected on the underbody,
or chassis, or under the hood.
These accumulations can be a fire
hazard.
After operation in mud or sand,
have the brake linings cleaned and
checked. These substances can
cause glazing and uneven braking.
Check the body structure, steering,
suspension, wheels, tires, and
exhaust system for damage and
check the fuel lines and cooling
system for any leakage.
More frequent maintenance
service is required. Refer to the
Maintenance Schedule for more
information.
Driving on Wet Roads
Rain and wet roads can reduce
vehicle traction and affect your
ability to stop and accelerate.
Always drive slower in these types
of driving conditions and avoid
driving through large puddles and
deep‐standing or flowing water.
{WARNING
Wet brakes can cause crashes.
They might not work as well in a
quick stop and could cause
pulling to one side. You could
lose control of the vehicle.
After driving through a large
puddle of water or a car/vehicle
wash, lightly apply the brake
pedal until the brakes work
normally.(Continued)
WARNING (Continued)
Flowing or rushing water creates
strong forces. Driving through
flowing water could cause the
vehicle to be carried away. If this
happens, you and other vehicle
occupants could drown. Do not
ignore police warnings and be
very cautious about trying to drive
through flowing water.