air conditioning GMC YUKON 2012 User Guide

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 (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.

Black plate (13,1)GMC Yukon/Yukon XL Owner Manual - 2012
Climate Controls 8-13
Air Vents
Use the air outlets located in the
center and on the side of the
instrument panel to direct the
airflow.
Operation Tips
.Keep the hood and front air
inlets free of ice, snow, or any
other obstruction (such as
leaves). The heater and
defroster will work far better,
reducing the chance of fogging
the inside of the windows.
.When you enter a vehicle in cold
weather, press the fan up button
to the maximum fan level before
driving. This helps clear the
intake ducts of snow and
moisture, and reduces the
chance of fogging the inside of
the window.
.Keep the air path under the front
seats clear of objects. This helps
air to circulate throughout the
vehicle.
.Adding outside equipment to the
front of the vehicle, such as
hood-air deflectors, may affect
the performance of the heating
and air conditioning system.
Check with your dealer before
adding equipment to the outside
of the vehicle.

Black plate (23,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-23
.Idles for long periods in traffic.
.Tows a trailer. SeeTrailer
Towing on page 9‑72.
If the overheat warning is displayed
with no sign of steam:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and to the highest
fan speed. Open the windows as
necessary.
3. In heavy traffic, let the engine idle in N (Neutral) while stopped.
If it is safe to do so, pull off the
road, shift to P (Park) or
N (Neutral) and let the
engine idle.
If the temperature overheat gauge
is no longer in the overheat zone
or an overheat warning no longer
displays, the vehicle can be driven.
Continue to drive the vehicle slowly
for about 10 minutes. Keep a safe
vehicle distance from the vehicle in
front. If the warning does not come
back on, continue to drive normally. If the warning continues, pull
over, stop, and park the vehicle
right away.
If there is no sign of steam, idle
the engine for three minutes
while parked. If the warning is still
displayed, turn off the engine until it
cools down. Also, see
“Overheated
Engine Protection Operating Mode”
later in this section.
Overheated Engine
Protection
Operating Mode
If an overheated engine condition
exists and the ENGINE POWER IS
REDUCED message is displayed,
an overheat protection mode which
alternates firing groups of cylinders
helps prevent engine damage. In
this mode, a loss in power and
engine performance will be noticed.
This operating mode allows the
vehicle to be driven to a safe place
in an emergency. Driving extended distances and/or towing a trailer in
the overheat protection mode
should be avoided.
Notice:
After driving in the
overheated engine protection
operating mode, to avoid engine
damage, allow the engine to cool
before attempting any repair.
The engine oil will be severely
degraded. Repair the cause of
coolant loss, change the oil and
reset the oil life system. See
Engine Oil on page 10‑8.
Engine Fan
If the vehicle has a clutched engine
cooling fan, when the clutch is
engaged, the fan spins faster to
provide more air to cool the engine.
In most everyday driving conditions,
the fan is spinning slower and the
clutch is not fully engaged.
This improves fuel economy and
reduces fan noise. Under heavy
vehicle loading, trailer towing, and/
or high outside temperatures, the
fan speed increases as the clutch

Black plate (24,1)GMC Yukon/Yukon XL Owner Manual - 2012
10-24 Vehicle Care
more fully engages, so an increase
in fan noise may be heard. This is
normal and should not be mistaken
as the transmission slipping or
making extra shifts. It is merely the
cooling system functioning properly.
The fan will slow down when
additional cooling is not required
and the clutch disengages.
This fan noise may also be heard
when starting the engine. It will go
away as the fan clutch partially
disengages.
If the vehicle has electric cooling
fans, the fans may be heard
spinning at low speed during most
everyday driving. The fans may turn
off if no cooling is required. Under
heavy vehicle loading, trailer
towing, high outside temperatures,
or operation of the air conditioning
system, the fans may change to
high speed and an increase in fan
noise may be heard. This is normal
and indicates that the cooling
system is functioning properly.The fans will change to low speed
when additional cooling is no longer
required.
Power Steering Fluid
If the vehicle is a hybrid, see the
hybrid supplement for more
information.
See
Engine Compartment Overview
on page 10‑6 for reservoir location.
When to Check Power Steering
Fluid
It is not necessary to regularly
check power steering fluid unless
there is a leak suspected in the
system or an unusual noise is
heard. A fluid loss in this system
could indicate a problem. Have the
system inspected and repaired.
How to Check Power Steering
Fluid
Notice:Extremely small amounts
of contamination can cause
steering system damage and
cause it to not work properly. Do
not allow contaminants to contact
the fluid side of the reservoir
cap/dipstick or from entering the
reservoir.
To check the power steering fluid:
1. Turn the key off and let the engine compartment cool down.
2. Wipe the cap and the top of the reservoir clean.
3. Unscrew the cap and wipe the dipstick with a clean rag.
4. Replace the cap and completely tighten it.
5. Remove the cap again and look at the fluid level on the dipstick.

Black plate (43,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-43
The vehicle may not be equipped
with all of the fuses, relays, and
features shown.Fuses Usage
1 Right Trailer
Stop/Turn Lamp
2 Electronic Stability
Suspension Control,
Automatic Level
Control Exhaust
3 Left Trailer
Stop/Turn Lamp
4 Engine Controls
5 Engine Control
Module, Throttle
Control
6 Trailer Brake
Controller
7 Front Washer
8 Oxygen Sensors
9 Antilock Brakes
System 2 Fuses
Usage
10 Trailer Back-up
Lamps
11 Driver Side
Low-Beam Headlamp
12 Engine Control
Module (Battery)
13 Fuel Injectors, Ignition
Coils (Right Side)
14 Transmission Control
Module (Battery)
15 Vehicle Back-up
Lamps
16 Passenger Side
Low-Beam Headlamp
17 Air Conditioning
Compressor
18 Oxygen Sensors
19 Transmission Controls
(Ignition)
20 Fuel Pump Fuses
Usage
21 Fuel System Control
Module
22 Headlamp Washer
23 Rear Windshield
Washer
24 Fuel Injectors, Ignition
Coils (Left Side)
25 Trailer Parking Lamps
26 Driver Side Parking
Lamps
27 Passenger Side
Parking Lamps
28 Fog Lamps
29 Horn
30 Passenger Side
High-Beam Headlamp
31 Daytime Running
Lamps (DRL)
(If Equipped)
32 Driver Side
High-Beam Headlamp

Black plate (45,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-45
J-CaseFuses Usage
66 Not Used
67 Transfer Case
68 Stud 1 (Trailer
Connector Battery
Power)
69 Mid-Bussed Electrical
Center 1
70 Climate Control
Blower
71 Power Liftgate
Module
72 Left Bussed Electrical
Center 2
Relays Usage
FAN HI Cooling Fan High
Speed
FAN LO Cooling Fan Low
Speed
FAN
CNTRL Cooling Fan Control Relays Usage
HDLP
LO/HID Low-Beam Headlamp
FOG
LAMP Front Fog Lamps
A/C
CMPRSR Air Conditioning
Compressor
STRTR Starter
PWR/TRN Powertrain
FUEL
PMP Fuel Pump
PRK
LAMP Parking Lamps
REAR
DEFOG Rear Defogger
RUN/
CRNK Switched PowerInstrument Panel Fuse
Block
The instrument panel fuse block
access door is located on the driver
side edge of the instrument panel.
Pull off the cover to access the fuse
block.

Black plate (53,1)GMC Yukon/Yukon XL Owner Manual - 2012
Vehicle Care 10-53
size mean a light truck tire
engineered to standards
set by the U.S. Tire and Rim
Association.
(B) Tire Width
:The three‐digit
number indicates the tire section
width in millimeters from
sidewall to sidewall.
(C) Aspect Ratio
:A two‐digit
number that indicates the tire
height‐to‐width measurements.
For example, if the tire size
aspect ratio is 75, as shown
in item C of the light truck
(LT‐Metric) tire illustration, it
would mean that the tire's
sidewall is 75 percent as high
as it is wide. (D) Construction Code
:A
letter code is used to indicate
the type of ply construction in
the tire. The letter R means
radial ply construction; the
letter D means diagonal or bias
ply construction; and the letter B
means belted‐bias ply
construction.
(E) Rim Diameter
:Diameter of
the wheel in inches.
(F) Load Range
:Load Range.
(G) Service Description
:The
service description indicates the
load index and speed rating of a
tire. If two numbers are given as
in the example, 120/116, then
this represents the load index for
single versus dual wheel usage
(single/dual). The speed rating is
the maximum speed a tire is
certified to carry a load.
Tire Terminology and
Definitions
Air Pressure:The amount of
air inside the tire pressing
outward on each square inch
of the tire. Air pressure is
expressed in kPa (kilopascal)
or psi (pounds per square inch).
Accessory Weight
:The
combined weight of optional
accessories. Some examples
of optional accessories are
automatic transmission, power
steering, power brakes, power
windows, power seats, and air
conditioning.
Aspect Ratio
:The relationship
of a tire's height to its width.
Belt
:A rubber coated layer of
cords that is located between
the plies and the tread. Cords
may be made from steel or other
reinforcing materials.

Black plate (2,1)GMC Yukon/Yukon XL Owner Manual - 2012
12-2 Technical Data
Vehicle Data
Capacities and Specifications
If your vehicle is a Hybrid, see the Hybrid manual for more information.
The following approximate capacities are given in metric and English conversions. SeeRecommended Fluids and
Lubricants on page 11‑11 for more information.
Application Capacities
Metric English
Air Conditioning Refrigerant R134a For the air conditioning system refrigerant charge
amount, see the refrigerant label located under the hood. See your dealer for more information.
Cooling System
5.3L V8 17.3 L 18.3 qt
6.0L V8 16.5 L 17.4 qt
Engine Oil with Filter 5.7 L 6.0 qt
Fuel Tank
Regular 98.4 L 26.0 gal
Extended 1500 Series 119.2 L 31.5 gal
Extended 2500 Series 147.6 L 39.0 gal