2008 GMC YUKON DENALI service indicator

Seats and Restraint Systems........................... 1-1
Front Seats
............................................... 1-2
Rear Seats
............................................... 1-9
Safety Belts
.............................................1-28
Child Restraints
.......................................1-49
Airbag System
.........................................1-75
Restraint System Check
............................1-92
Features and Controls..................................... 2-1
Keys
........................................................ 2-3
Doors and Locks
......................................2-10
Windows
.................................................2-19
Theft-Deterrent Systems
............................2-21
Starting and Operating Your Vehicle
...........2-25
Mirrors
....................................................2-40
Object Detection Systems
..........................2-44
OnStar
®System
......................................2-47
Universal Home Remote System
................2-50
Storage Areas
.........................................2-58
Sunroof
..................................................2-62
Instrument Panel............................................. 3-1
Instrument Panel Overview
.......................... 3-4
Climate Controls
......................................3-23
Warning Lights, Gages, and Indicators
........3-31
Driver Information Center (DIC)
..................3-49
Audio System(s)
.......................................3-73Driving Your Vehicle....................................... 4-1
Your Driving, the Road, and Your Vehicle
..... 4-2
Towing
...................................................4-40
Service and Appearance Care.......................... 5-1
Service
..................................................... 5-3
Fuel
......................................................... 5-5
Checking Things Under the Hood
...............5-10
All-Wheel Drive
........................................5-45
Rear Axle
...............................................5-46
Front Axle
...............................................5-47
Headlamp Aiming
.....................................5-48
Bulb Replacement
....................................5-50
Windshield Wiper Blade Replacement
.........5-53
Tires
......................................................5-55
Appearance Care
.....................................5-98
Vehicle Identication
...............................5-107
Electrical System
....................................5-108
Capacities and Specications
...................5-114
Maintenance Schedule..................................... 6-1
Maintenance Schedule
................................ 6-2
Customer Assistance Information.................... 7-1
Customer Assistance and Information
........... 7-2
Reporting Safety Defects
...........................7-13
Vehicle Data Recording and Privacy
...........7-15
Index.................................................................1
2008 GMC Yukon Denali/Yukon XL Denali Owner ManualM

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

{CAUTION:
If the airbag readiness light stays on after you
start your vehicle, it means the airbag system
may not be working properly. The airbags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the airbag
readiness light stays on after you start your
vehicle.
The airbag readiness light should ash for a few
seconds when you start the engine. If the light does not
come on then, have it xed immediately. If there is a
problem with the airbag system, an airbag Driver
Information Center (DIC) message may also come on.
SeeDIC Warnings and Messages on page 3-56for
more information.
Passenger Airbag Status Indicator
Your vehicle has the passenger sensing system.
Your overhead console has a passenger airbag status
indicator.
When you start the vehicle, the passenger airbag status
indicator will light ON and OFF, or the symbol for on
and off, for several seconds as a system check.
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’s
frontal airbag.United States
Canada
3-35

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/retailer for service.
{CAUTION:
If the airbag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
airbag system. If this ever happens, have the
vehicle serviced promptly, because an
adult-size person sitting in the right front
passenger’s seat may not have the protection
of the airbag(s). SeeAirbag Readiness Light
on page 3-34for more on this, including
important safety information.
Charging System Light
This light will come on
briey when you turn on
the ignition, but the engine
is not running, as a
check to show you it is
working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have a
problem with the charging system. A charging system
Driver Information Center (DIC) message may also
appear. SeeDIC Warnings and Messages on page 3-56
for more information. This light could indicate that you
have problems with a generator drive belt, or another
electrical problem. Have it checked right away. If
you must drive a short distance with the light on, be
certain to turn off all your accessories, such as the radio
and air conditioner.
3-37

Antilock Brake System
Warning Light
For vehicles with the
Antilock Brake System
(ABS), this light will come
on briey when you
start the engine.
That is normal. If the light does not come on then, have it
xed so it will be ready to warn you if there is a problem.
If the ABS light stays on, turn the ignition off, if the light
comes on when you are driving, stop as soon as it
is safely possible and turn the ignition off. Then start the
engine again to reset the system. If the ABS light still
stays on, or comes on again while you are driving, your
vehicle needs service. If the regular brake system
warning light is not on, you still have brakes, but you do
not have antilock brakes. If the regular brake system
warning light is also on, you do not have antilock brakes
and there is a problem with your regular brakes. See
Brake System Warning Light on page 3-39
For vehicles with a Driver Information Center (DIC), see
DIC Warnings and Messages on page 3-56for all
brake related DIC messages.
StabiliTrak®Indicator Light
For vehicles that have the
StabiliTrak®system, this
warning light should
come on briey when the
engine is started.
If the warning light does not come on then, have it xed
so it will be ready to warn you if there is a problem. If
it stays on, or comes on when you are driving, there may
be a problem with your StabiliTrak
®system and your
vehicle may need service. When this warning light is on,
the system will not limit wheel spin. Adjust your driving
accordingly.
If the StabiliTrak
®system warning light comes on and
stays on for an extended period of time when the system
is turned on, your vehicle needs service. See
StabiliTrak
®System on page 4-6for more information.
3-40

Malfunction Indicator Lamp
Check Engine Light
A computer system called OBD II (On-Board
Diagnostics-Second Generation) monitors operation of
the fuel, ignition, and emission control systems. It makes
sure that emissions are at acceptable levels for the life of
the vehicle, helping to produce a cleaner environment.
The check engine light
comes on to indicate that
there is an OBD II
problem and service is
required.
Malfunctions often are indicated by the system before
any problem is apparent. This can prevent more serious
damage to your vehicle. This system is also designed
to assist your service technician in correctly diagnosing
any malfunction.
Notice:If you keep driving your vehicle with this
light on, after a while, the emission controls
might not work as well, your vehicle’s 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 your warranty.Notice:Modications made to the engine,
transmission, exhaust, intake, or fuel system of
your vehicle or the replacement of the original tires
with other than those of the same Tire Performance
Criteria (TPC) can affect your vehicle’s emission
controls and can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions
and could damage the emission control system on
your vehicle. Diagnosis and service might be
required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
3-42

Fuel
Use of the recommended fuel is an important part of the
proper maintenance of your vehicle. To help keep the
engine clean and maintain optimum vehicle
performance, we recommend the use of gasoline
advertised as TOP TIER Detergent Gasoline.
Gasoline Octane
Use premium unleaded gasoline with a posted octane
rating of 91 or higher. You can also use regular
unleaded gasoline rated at 87 octane or higher, but
your vehicle’s acceleration could be slightly reduced,
and you might notice a slight audible knocking noise,
commonly referred to as spark knock. If the octane is less
than 87, you might notice a heavy knocking noise when
you drive. If this occurs, use a gasoline rated at 87 octane
or higher as soon as possible. Otherwise, you could
damage the engine. If you are using gasoline rated at 87
octane or higher and you hear heavy knocking, the
engine needs service.
Gasoline Specications
At a minimum, gasoline should meet ASTM specication
D 4814 in the United States or CAN/CGSB-3.5 or 3.511
in Canada. Some gasolines contain an octane-enhancing
additive called methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend against the use of
gasolines containing MMT. SeeAdditives on page 5-6for
additional information.
California Fuel
If your vehicle is certied to meet California Emissions
Standards, it is designed to operate on fuels that meet
California specications. See the underhood emission
control label. If this fuel is not available in states adopting
California emissions standards, your vehicle will operate
satisfactorily on fuels meeting federal specications, but
emission control system performance might be affected.
The malfunction indicator lamp could turn on and your
vehicle might fail a smog-check test. SeeMalfunction
Indicator Lamp on page 3-42. If this occurs, return to your
authorized dealer/retailer for diagnosis. If it is determined
that the condition is caused by the type of fuel used,
repairs might not be covered by your warranty.
5-5

Additives
To provide cleaner air, all gasolines in the United States
are now required to contain additives that help prevent
engine and fuel system deposits from forming, allowing
the emission control system to work properly. In most
cases, you should not have to add anything to the fuel.
However, some gasolines contain only the minimum
amount of additive required to meet U.S. Environmental
Protection Agency regulations. To help keep fuel injectors
and intake valves clean, or if your vehicle experiences
problems due to dirty injectors or valves, look for gasoline
that is advertised as TOP TIER Detergent Gasoline. Also,
your dealer/retailer has additives that will help correct and
prevent most deposit-related problems.
Gasolines containing oxygenates, such as ethers and
ethanol, and reformulated gasolines might be available
in your area. We recommend that you use these
gasolines, if they comply with the specications described
earlier. However, E85 (85% ethanol) and other fuels
containing more than 10% ethanol must not be used in
vehicles that were not designed for those fuels.
Notice:Your vehicle was not designed for fuel that
contains methanol. Do not use fuel containing
methanol. It can corrode metal parts in the fuel
system and also damage plastic and rubber parts.
That damage would not be covered under your
warranty.Some gasolines that are not reformulated for low
emissions can contain an octane-enhancing additive
called methylcyclopentadienyl manganese tricarbonyl
(MMT); ask the attendant where you buy gasoline
whether the fuel contains MMT. We recommend against
the use of such gasolines. Fuels containing MMT can
reduce the life of spark plugs and the performance of the
emission control system could be affected. The
malfunction indicator lamp might turn on. If this occurs,
return to your dealer/retailer for service.
Fuels in Foreign Countries
If you plan on driving in another country outside the
United States or Canada, the proper fuel might be hard
to nd. Never use leaded gasoline or any other fuel
not recommended in the previous text on fuel. Costly
repairs caused by use of improper fuel would not be
covered by your warranty.
To check the fuel availability, ask an auto club, or
contact a major oil company that does business in the
country where you will be driving.
5-6