2012 GMC YUKON air condition

Black plate (43,1)GMC Yukon/Yukon XL Owner Manual - 2012
Seats and Restraints 3-43
keep the airbag system from
working properly. Changing or
moving any parts of the front
seats, safety belts, the airbag
sensing and diagnostic module,
steering wheel, instrument
panel, roof-rail airbag modules,
ceiling headliner or pillar garnish
trim, overhead console, front
sensors, side impact sensors,
or airbag wiring can affect the
operation of the airbag system.
In addition, the vehicle may have
a passenger sensing system for
the right front passenger's
position, which includes sensors
that are part of the passenger's
seat. The passenger sensing
system may not operate properly
if the original seat trim is
replaced with non-GM covers,
upholstery or trim, or with GM
covers, upholstery or trim
designed for a different vehicle.Any object, such as an
aftermarket seat heater or a
comfort enhancing pad or
device, installed under or on top
of the seat fabric, could also
interfere with the operation of
the passenger sensing system.
This could either prevent proper
deployment of the passenger
airbag(s) or prevent the
passenger sensing system from
properly turning off the
passenger airbag(s). See
Passenger Sensing System on
page 3‑38.
If you have any questions about
this, you should contact
Customer Assistance before you
modify your vehicle. The phone
numbers and addresses for
Customer Assistance are in
Step Two of the Customer
Satisfaction Procedure in this
manual. See
Customer
Satisfaction Procedure on
page 13‑1. If the vehicle has rollover
roof-rail airbags, see
Different
Size Tires and Wheels on
page 10‑66 for additional
important information.
Q: What if I added a snow plow? Will it keep the airbags from
working properly?
A: We have designed our airbag
systems to work properly under
a wide range of conditions,
including snow plowing with
vehicles that have the optional
Snow Plow Prep Package
(RPO VYU). But do not change
or defeat the snow plow's
“tripping mechanism.” If you do,
it can damage your snow plow
and your vehicle, and it may
cause an airbag inflation.

Black plate (52,1)GMC Yukon/Yukon XL Owner Manual - 2012
3-52 Seats and Restraints
We recommend that children and
child restraints be secured in a rear
seat, including: an infant or a child
riding in a rear-facing child restraint;
a child riding in a forward-facing
child seat; an older child riding in a
booster seat; and children, who are
large enough, using safety belts.
A label on your sun visor says,
“Never put a rear-facing child seat in
the front.”This is because the risk to
the rear-facing child is so great,
if the airbag deploys.
{WARNING
A child in a rear-facing child
restraint can be seriously injured
or killed if the right front
passenger airbag inflates. This is
because the back of the
rear-facing child restraint would
be very close to the inflating
airbag. A child in a forward-facing
child restraint can be seriously
injured or killed if the right front
(Continued)
WARNING (Continued)
passenger airbag inflates and the
passenger seat is in a forward
position.
The vehicle may have a
passenger sensing system which
is designed to turn off the right
front passenger frontal airbag
under certain conditions.
Even if the passenger sensing
system, if equipped, has turned
off the right front passenger
frontal airbag, no system is
fail-safe. No one can guarantee
that an airbag will not deploy
under some unusual
circumstance, even though it is
turned off.
Secure rear-facing child
restraints in a rear seat, even if
the airbag is off. If you secure a
forward-facing child restraint in
the right front seat, always move(Continued)
WARNING (Continued)
the front passenger seat as far
back as it will go. It is better to
secure the child restraint in a
rear seat.
SeePassenger Sensing System
on page 3‑38 for additional
information.
{WARNING
A child in a child restraint in the
center front seat can be badly
injured or killed by the frontal
airbags if they inflate. Never
secure a child restraint in the
center front seat. It is always
better to secure a child restraint in
a rear seat.
Do not use child restraints in the
center front seat position.

Black plate (63,1)GMC Yukon/Yukon XL Owner Manual - 2012
Seats and Restraints 3-63
6. If the child restraint has a toptether, follow the child restraint
manufacturer's instructions
regarding the use of the top
tether. See Lower Anchors and
Tethers for Children (LATCH
System) on page 3‑53 for more
information.
7. Before placing a child in the child restraint, make sure it is
securely held in place. To check,
grasp the child restraint at the
safety belt path and attempt
to move it side‐to‐side and
back‐and‐forth. When the child
restraint is properly installed,
there should be no more than
2.5 cm (1 in) of movement.
To remove the child restraint,
unbuckle the vehicle safety belt and
let it return to the stowed position.
If the top tether is attached to a top
tether anchor, disconnect it.Securing Child Restraints
(Center Front Seat
Position)
{WARNING
A child in a child restraint in the
center front seat can be badly
injured or killed by the frontal
airbags if they inflate. Never
secure a child restraint in the
center front seat. It is always
better to secure a child restraint in
a rear seat.
Do not use child restraints in the
center front seat position.
Securing Child Restraints
(Right Front Seat
Position)
This vehicle has airbags. A rear
seat is a safer place to secure a
forward-facing child restraint. See
Where to Put the Restraint on
page 3‑51.
In addition, the vehicle may have a
passenger sensing system which is
designed to turn off the right front
passenger frontal airbag under
certain conditions. See Passenger
Sensing System on page 3‑38 and
Passenger Airbag Status Indicator
on page 5‑19 for more information,
including important safety
information.
A label on the sun visor says,
“Never put a rear-facing child seat in
the front.” This is because the risk to
the rear-facing child is so great if the
airbag deploys.

Black plate (64,1)GMC Yukon/Yukon XL Owner Manual - 2012
3-64 Seats and Restraints
{WARNING
A child in a rear-facing child
restraint can be seriously
injured or killed if the right front
passenger airbag inflates.
This is because the back of the
rear-facing child restraint would
be very close to the inflating
airbag. A child in a forward-facing
child restraint can be seriously
injured or killed if the right front
passenger airbag inflates and the
passenger seat is in a forward
position.
The vehicle may have a
passenger sensing system which
is designed to turn off the right
front passenger frontal airbag
under certain conditions.(Continued)
WARNING (Continued)
Even if the passenger sensing
system, if equipped, has turned
off the right front passenger
frontal airbag, no system is
fail-safe. No one can guarantee
that an airbag will not deploy
under some unusual
circumstance, even
though it is turned off.
Secure rear-facing child
restraints in a rear seat, even if
the airbag is off. If you secure a
forward-facing child restraint in
the right front seat, always move
the front passenger seat as far
back as it will go. It is better to
secure the child restraint in a
rear seat.
SeePassenger Sensing System
on page 3‑38 for additional
information. If the child restraint has the LATCH
system, see
Lower Anchors and
Tethers for Children (LATCH
System) on page 3‑53 for how and
where to install the child restraint
using LATCH. If a child restraint is
secured using a safety belt and it
uses a top tether, see Lower
Anchors and Tethers for Children
(LATCH System) on page 3‑53 for
top tether anchor locations.
Do not secure a child seat in a
position without a top tether anchor
if a national or local law requires
that the top tether be anchored, or if
the instructions that come with the
child restraint say that the top strap
must be anchored.
In Canada, the law requires that
forward-facing child restraints have
a top tether, and that the tether be
attached.

Black plate (20,1)GMC Yukon/Yukon XL Owner Manual - 2012
5-20 Instruments and Controls
Then, after several more seconds,
the status indicator will light either
ON or OFF, or either the on or off
symbol to let you know the status of
the right front passenger frontal
airbag.
If the word ON or the on symbol is
lit on the passenger airbag status
indicator, it means that the right
front passenger frontal airbag is
enabled (may inflate).
If the word OFF or the off symbol is
lit on the airbag status indicator, it
means that the passenger sensing
system has turned off the right front
passenger frontal airbag.
If, after several seconds, both status
indicator lights remain on, or if there
are no lights at all, there may be a
problem with the lights or the
passenger sensing system. See
your dealer for service.{WARNING
If the airbag readiness light ever
comes on and stays on, it means
that something may be wrong
with the airbag system. To help
avoid injury to yourself or others,
have the vehicle serviced right
away. SeeAirbag Readiness
Light on page 5‑18 for more
information, including important
safety information.
Charging System Light
This light comes on briefly when the
ignition key is turned to START, but
the engine is not running, as a
check to show it is working. If it does not, have the vehicle
serviced by your dealer.
The light should go out once the
engine starts. If it stays on,
or comes on while driving, there
could be a problem with the
charging system. A charging system
message in the Driver Information
Center (DIC) can also appear. See
Battery Voltage and Charging
Messages on page 5‑38
for more
information. This light could indicate
that there are problems with a
generator drive belt, or that there is
an electrical problem. Have it
checked right away. If the vehicle
must be driven a short distance with
the light on, turn off accessories,
such as the radio and air
conditioner.
If the vehicle is a hybrid, see the
hybrid supplement for more
information.

Black plate (21,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-21
Malfunction
Indicator Lamp
A computer system called OBD II
(On-Board Diagnostics-Second
Generation) monitors the operation
of the vehicle to ensure emissions
are at acceptable levels, to produce
a cleaner environment. This light
comes on when the vehicle is
placed in ON/RUN, as a check to
show it is working. If it does not,
have the vehicle serviced by your
dealer. SeeIgnition Positions on
page 9‑22 for more information.
If the malfunction indicator lamp
comes on and stays on while the
engine is running, this indicates that
there is an OBD II problem and
service is required.
Malfunctions often are indicated by
the system before any problem is
apparent. Being aware of the light
can prevent more serious damage
to the vehicle. This system assists
the service technician in correctly
diagnosing any malfunction.
Notice:If the vehicle is
continually driven with this light
on, the emission controls might
not work as well, the vehicle fuel
economy might not be as good,
and the engine might not run as
smoothly. This could lead to
costly repairs that might not be
covered by the vehicle warranty. Notice:
Modifications made to the
engine, transmission, exhaust,
intake, or fuel system of the
vehicle or the replacement of the
original tires with other than
those of the same Tire
Performance Criteria (TPC) can
affect the vehicle's emission
controls and can cause this light
to come on. Modifications to
these systems could lead to
costly repairs not covered by the
vehicle warranty. This could also
result in a failure to pass a
required Emission Inspection/
Maintenance test. See
Accessories and Modifications on
page 10‑3.
This light comes on during a
malfunction in one of two ways:
Light Flashing: A misfire condition
has been detected. A misfire
increases vehicle emissions and
could damage the emission control
system on the vehicle. Diagnosis
and service might be required.

Black plate (39,1)GMC Yukon/Yukon XL Owner Manual - 2012
Instruments and Controls 5-39
See“Integrated Trailer Brake
Control System” underTowing
Equipment on page 9‑76 for more
information.
Door Ajar Messages
DRIVER DOOR OPEN
This message displays and a chime
sounds if the driver door is not fully
closed and the vehicle is shifted out
of P (Park). Stop and turn off the
vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
HOOD OPEN
This message displays and a chime
sounds if the hood is not fully
closed. Stop and turn off the
vehicle, check the hood for
obstructions, and close the hood
again. Check to see if the message
still appears on the DIC.
LEFT REAR DOOR OPEN
This message displays and a chime
sounds if the driver side rear door is
not fully closed and the vehicle is
shifted out of P (Park). Stop and turn
off the vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
PASSENGER DOOR OPEN
This message displays and a chime
sounds if the front passenger door
is not fully closed and the vehicle is
shifted out of P (Park). Stop and turn
off the vehicle, check the door for
obstructions, and close the door
again. Check to see if the message
still appears on the DIC.
REAR ACCESS OPEN
This message displays and a chime
sounds if the liftgate or liftglass is
open while the ignition is in ON/
RUN. Turn off the vehicle and check
the liftgate and liftglass. Restart the
vehicle and check for the message
on the DIC display.
RIGHT REAR DOOR OPEN
This message displays and a chime
sounds if the passenger side rear
door is not fully closed and the
vehicle is shifted out of P (Park).
Stop and turn off the vehicle, check
the door for obstructions, and close
the door again. Check to see if the
message still appears on the DIC.
Engine Cooling System
Messages
ENGINE HOT A/C (Air
Conditioning) TURNED OFF
This message displays when the
engine coolant becomes hotter than
the normal operating temperature.
See Engine Coolant Temperature
Gauge on page 5‑16. To avoid
added strain on a hot engine, the air
conditioning compressor
automatically turns off. When the
coolant temperature returns to
normal, the air conditioning
compressor turns back on. You can
continue to drive your vehicle.

Black plate (44,1)GMC Yukon/Yukon XL Owner Manual - 2012
5-44 Instruments and Controls
page 9‑15. To turn the StabiliTrak
system on or off, seeStabiliTrak®
System on page 9‑46.
STABILITRAK OFF may also
display when the stability control
has been automatically disabled.
There are several conditions that
can cause this message to appear.
.One condition is overheating,
which could occur if StabiliTrak
activates continuously for an
extended period of time.
.The message also displays if the
brake system warning light is on.
SeeBrake System Warning
Light on page 5‑23.
.The message could display if the
stability system takes longer
than usual to complete its
diagnostic checks due to driving
conditions.
.The message displays if an
engine or vehicle related
problem has been detected and
the vehicle needs service. See
your dealer. The message turns off as soon as
the conditions that caused the
message to be displayed are no
longer present.
Airbag System Messages
SERVICE AIR BAG
This message displays if there is a
problem with the airbag system.
Have your dealer inspect the
system for problems. See
Airbag
Readiness Light on page 5‑18 and
Airbag System on page 3‑30 for
more information.
Anti-theft Alarm System
Messages
SERVICE THEFT DETERRENT
SYSTEM
This message displays when there
is a problem with the theft-deterrent
system. The vehicle may or may not
restart so you may want to take the
vehicle to your dealer before turning off the engine. See
Immobilizer
Operation on page 2‑15 for more
information.
Tire Messages
SERVICE TIRE MONITOR
SYSTEM
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays if a part on the
TPMS is not working properly. The
tire pressure light also flashes and
then remains on during the same
ignition cycle. See Tire Pressure
Light on page 5‑26. Several
conditions may cause this message
to appear. See Tire Pressure
Monitor Operation on page 10‑59 for
more information. If the warning
comes on and stays on, there may
be a problem with the TPMS. See
your dealer.
TIRE LEARNING ACTIVE
On vehicles with the Tire Pressure
Monitor System (TPMS), this
message displays when the TPMS