2008 GMC YUKON DENALI air condition

Shoulder Belt Height Adjuster
Your vehicle has a shoulder belt height adjuster for the
driver and right front passenger position.
Adjust the height so that the shoulder portion of the belt is
centered on your shoulder. The belt should be away from
your face and neck, but not falling off your shoulder.
Improper shoulder belt height adjustment could reduce
the effectiveness of the safety belt in a crash.
To move it down, squeeze
the buttons (A) on the sides
of the height adjuster and
move the height adjuster to
the desired position.
You can move the adjuster up just by pushing up on the
shoulder belt guide.
After you move the adjuster to where you want it, try to
move it down without squeezing the buttons to make
sure it has locked into position.
Safety Belt Pretensioners
Your vehicle has safety belt pretensioners for front
outboard occupants. Although you cannot see them,
they are part of the safety belt assembly. They can help
tighten the safety belts during the early stages of a
moderate to severe frontal, near frontal, or rear crash if
the threshold conditions for pretensioner activation
are met. And, if your vehicle has side impact airbags,
safety belt pretensioners can help tighten the safety
belts in a side crash or a rollover event.
Pretensioners work only once. If they activate in a
crash, you will need to get new ones, and probably other
new parts for your safety belt system. SeeReplacing
Restraint System Parts After a Crash on page 1-93.
1-43

Securing a Child Restraint in the
Center Front Seat Position
{CAUTION:
A child in a child restraint in the center front
seat can be badly injured or killed by the
frontal airbags if they inate. 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 a Child Restraint in the
Right Front Seat Position
Your vehicle has airbags. A rear seat is a safer place to
secure a forward-facing child restraint. SeeWhere to
Put the Restraint on page 1-58.
In addition, your vehicle has a passenger sensing
system which is designed to turn off the right front
passenger’s frontal airbag under certain conditions. See
Passenger Sensing System on page 1-85and
Passenger Airbag Status Indicator on page 3-35for
more information on this, including important safety
information.
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Airbags are designed to inate only once. After an
airbag inates, you will need some new parts for
the airbag system. If you do not get them, the airbag
system will not be there to help protect you in
another crash. A new system will include airbag
modules and possibly other parts. The service
manual for your vehicle covers the need to replace
other parts.
Your vehicle has a crash sensing and diagnostic
module which records information after a crash.
SeeVehicle Data Recording and Privacy on
page 7-15andEvent Data Recorders on page 7-16.
Let only qualied technicians work on the airbag
systems. Improper service can mean that an
airbag system will not work properly. See your
dealer/retailer for service.
Passenger Sensing System
Your vehicle has a passenger sensing system for the
right front passenger’s position. The passenger
airbag status indicator will be visible on the overhead
console when you start your vehicle.
The words ON and OFF, or the symbol for on and off,
will be visible during the system check. When the
system check is complete, either the word ON or the
word OFF, or the symbol for on or the symbol for off, will
be visible. SeePassenger Airbag Status Indicator on
page 3-35.
The passenger sensing system will turn off the right
front passenger’s frontal airbag under certain conditions.
The driver’s airbags are not part of the passenger
sensing system.United States
Canada
1-85

Remote Vehicle Start
Your vehicle may have a remote starting feature. This
feature allows you to start the engine from outside of the
vehicle. It may also start up the vehicle’s heating or
air conditioning systems and rear window defogger.
Normal operation of the system will return after the key
is turned to the ON/RUN position.
If your vehicle has an automatic climate control system,
the climate control system will default to a heating or
cooling mode depending on the outside temperatures. If
your vehicle does not have an automatic climate control
system, the system will turn on at the setting the vehicle
was set to when the vehicle was last turned off.
During a remote start, if your vehicle has an automatic
climate control system and heated seats, the heated
seats will turn on during colder outside temperatures and
will shut off when the key is turned to ON/RUN. If
your vehicle does not have an automatic climate control
system, during remote start, you will need to manually
turn the heated seats on and off. SeeHeated Seats
on page 1-4for additional information.Laws in some communities may restrict the use of
remote starters. For example, some laws may require a
person using the remote start to have the vehicle in
view when doing so. Check local regulations for
any requirements on remote starting of vehicles.
Do not use the remote start feature if your vehicle is low
on fuel. Your vehicle may run out of fuel.
The RKE transmitter with the remote start button,
provides an increased range of operation. However, the
range may be less while the vehicle is running. As a
result, you may need to be closer to your vehicle to turn
it off, than you were to turn it on.
There are other conditions which can affect the
performance of the transmitter, seeRemote Keyless
Entry (RKE) System on page 2-4for additional
information.
/(Remote Start):This button will be on the RKE
transmitter if you have remote start.
2-8

DRIVE (D):This position is for normal driving. It
provides the best fuel economy for your vehicle. If you
need more power for passing, and you are:
Going less than about 35 mph (55 km/h), push your
accelerator pedal about halfway down.
Going about 35 mph (55 km/h) or more, push the
accelerator all the way down.
DRIVE (D) can be used when towing a trailer, carrying a
heavy load, driving on steep hills, or for off-road
driving. You may want to shift the transmission to a
lower gear selection if the transmission shifts too often.
Downshifting the transmission in slippery road
conditions could result in skidding, see “Skidding” under
Loss of Control on page 4-12
When temperatures are very cold, the Hydra-Matic
®
Automatic Transmission’s gear shifting may be delayed
providing more stable shifts until the engine warms
up. Shifts may be more noticeable with a cold
transmission. This difference in shifting is normal.
MANUAL MODE (M):This position lets drivers select
the range of gears appropriate for current driving
conditions. See Range Selection Mode later in
this section.Notice:Spinning the tires or holding the vehicle in
one place on a hill using only the accelerator
pedal may damage the transmission. The repair will
not be covered by your warranty. If you are stuck,
do not spin the tires. When stopping on a hill,
use the brakes to hold the vehicle in place.
Your vehicle has a shift stabilization feature that adjusts
the transmission shifting to the current driving conditions
in order to reduce rapid upshifts and downshifts. This shift
stabilization feature is designed to determine, before
making an upshift, if the engine will be able to maintain
vehicle speed by analyzing things such as throttle
position, vehicle load, and hill grade. If the shift
stabilization feature determines that a current vehicle
speed cannot be maintained, the transmission does not
upshift and instead holds the current gear. In some
cases, this may appear to be a delayed shift, however the
transmission is operating normally.
Your vehicle’s transmission uses adaptive shift controls.
Adaptive shift controls continually compares key shift
parameters to pre programmed ideal shift conditions
stored in the transmissions computer. The transmission
constantly makes adjustments to improve vehicle
performance according to the way the vehicle is being
used, such as with a heavy load. During this adaptive
shift controls process, some shifts may feel different as
the transmission determines the best settings for a
particular shift.
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A tow bar is attached to your vehicle.
The vehicle’s bumper is damaged. Take the vehicle
to your dealer/retailer to repair the system.
Other conditions may affect system performance,
such as vibrations from a jackhammer or the
compression of air brakes on a very large truck.
If the system is still disabled, after driving forward at
least 15 mph (25 km/h), take your vehicle to your
dealer/retailer.
OnStar®System
OnStar uses several innovative technologies and live
advisors to provide you with a wide range of safety,
security, information, and convenience services. If your
airbags deploy, the system is designed to make an
automatic call to OnStar Emergency advisors who can
request emergency services be sent to your location.If you lock your keys in the vehicle, call OnStar at
1-888-4-ONSTAR and they can send a signal to unlock
your doors. If you need roadside assistance, press
the OnStar button and they can contact Roadside
Service for you.
OnStar service is provided to you subject to the OnStar
Terms and Conditions. You may cancel your OnStar
service at any time by contacting OnStar. A complete
OnStar Owner’s Guide and the OnStar Terms and
Conditions are included in the vehicle’s OnStar
Subscriber glove box literature. For more information,
visit onstar.com or onstar.ca, contact OnStar at
1-888-4-ONSTAR (1-888-466-7827) or TTY
1-877-248-2080, or press the OnStar button to speak
with an OnStar advisor 24 hours a day, 7 days a week.
Not all OnStar features are available on all vehicles.
To check if your vehicle is equipped to provide the
services described below, or for a full description of
OnStar services and system limitations, see the OnStar
Owner’s Guide in your glove box or visit onstar.com.
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Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Other Warning Devices...................................3-6
Horn.............................................................3-6
Tilt Wheel.....................................................3-7
Heated Steering Wheel...................................3-7
Turn Signal/Multifunction Lever.........................3-8
Turn and Lane-Change Signals........................3-8
Headlamp High/Low-Beam Changer..................3-9
Flash-to-Pass.................................................3-9
Windshield Wipers........................................3-10
Rainsense™ II Wipers...................................3-10
Windshield Washer.......................................3-11
Rear Window Wiper/Washer...........................3-12
Cruise Control..............................................3-13
Exterior Lamps.............................................3-16
Headlamps on Reminder................................3-17
Daytime Running Lamps (DRL).......................3-17
Automatic Headlamp System..........................3-18
Fog Lamps..................................................3-19
Instrument Panel Brightness...........................3-19
Dome Lamps...............................................3-19
Dome Lamp Override....................................3-20
Entry Lighting...............................................3-20
Exit Lighting.................................................3-20Front Reading Lamps....................................3-20
Electric Power Management...........................3-20
Battery Run-Down Protection..........................3-21
Accessory Power Outlet(s).............................3-21
Ashtray(s) and Cigarette Lighter......................3-22
Climate Controls............................................3-23
Dual Automatic Climate Control System...........3-23
Outlet Adjustment.........................................3-29
Rear Air Conditioning and Heating System
and Electronic Climate Controls
...................3-29
Warning Lights, Gages, and Indicators............3-31
Instrument Panel Cluster................................3-32
Speedometer and Odometer...........................3-33
Trip Odometer..............................................3-33
Tachometer.................................................3-33
Safety Belt Reminders...................................3-33
Airbag Readiness Light..................................3-34
Passenger Airbag Status Indicator...................3-35
Charging System Light..................................3-37
Voltmeter Gage............................................3-38
Brake System Warning Light..........................3-39
Antilock Brake System Warning Light...............3-40
StabiliTrak
®Indicator Light..............................3-40
Section 3 Instrument Panel
3-1

The passenger’s temperature setting can be set to match
the driver’s temperature setting by pressing the PASS
button and turning off the PASS indicator. When the
passenger’s temperature setting is set different than the
driver’s setting, the indicator on the PASS button will
illuminate and both the driver’s side and passenger’s side
temperature displays will be shown.
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
40°F (4°C). 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 will
illuminate in recirculation.
2. Set the driver’s and passenger’s temperature.
To nd your comfort setting, start with a 74°F (23°C)
temperature setting and allow about 20 minutes
for the system to regulate. Use the driver’s or
passenger’s temperature buttons to adjust the
temperature setting as necessary. If you choose the
temperature setting of 60°F (15°C), the system
will remain at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C),
the system will remain at the maximum heat setting.
Choosing either maximum setting will not cause
the vehicle to heat or cool any faster.
Be careful not to 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.
3-24