Black plate (34,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
3-34 Seats and Restraints
In any particular crash, no one can
say whether an airbag should have
inflated simply because of the
damage to a vehicle or because of
what the repair costs were. For
frontal airbags, inflation is
determined by what the vehicle hits,
the angle of the impact, and how
quickly the vehicle slows down. For
seat-mounted side impact and
roof-rail airbags, deployment is
determined by the location and
severity of the side impact. In a
rollover event, roof-rail airbag
deployment is determined by the
direction of the roll.
What Makes an Airbag
Inflate?
In a deployment event, the sensing
system sends an electrical signal
triggering a release of gas from the
inflator. Gas from the inflator fills the
airbag causing the bag to break out
of the cover and deploy. The inflator,
the airbag, and related hardware are
all part of the airbag module.Frontal airbag modules are located
inside the steering wheel and
instrument panel. For vehicles with
seat‐mounted side impact airbags,
there are airbags modules in the
side of the front seatbacks closest
to the door. For vehicles with
roof-rail airbags, there are airbag
modules in the ceiling of the vehicle,
near the side windows that have
occupant seating positions.
How Does an Airbag
Restrain?
In moderate to severe frontal or
near frontal collisions, even belted
occupants can contact the steering
wheel or the instrument panel. In
moderate to severe side collisions,
even belted occupants can contact
the inside of the vehicle.
Airbags supplement the protection
provided by safety belts. Frontal
airbags distribute the force of the
impact more evenly over the
occupant's upper body, stopping the
occupant more gradually. Seat‐mounted side impact and roof-rail
airbags distribute the force of the
impact more evenly over the
occupant's upper body.
Rollover capable roof-rail airbags
are designed to help contain the
head and chest of occupants in the
outboard seating positions in the
first, second, and third rows,
if equipped with a third row seat.
The rollover capable roof-rail
airbags are designed to help reduce
the risk of full or partial ejection in
rollover events, although no system
can prevent all such ejections.
But airbags would not help in many
types of collisions, primarily
because the occupant's motion is
not toward those airbags. See
When
Should an Airbag Inflate? on
page 3‑32 for more information.
Airbags should never be regarded
as anything more than a supplement
to safety belts.
Black plate (58,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
9-58 Driving and Operating
Recommended Fuel
Use regular unleaded gasoline with
a posted octane rating of 87 or
higher. If the octane rating is less
than 87, an audible knocking noise,
commonly referred to as spark
knock, might be heard when driving.
If this occurs, use a gasoline rated
at 87 octane or higher as soon as
possible. If heavy knocking is heard
when using gasoline rated at
87 octane or higher, the engine
needs service.
Gasoline Specifications
At a minimum, gasoline should meet
ASTM specification D 4814. Some
gasolines contain an
octane-enhancing additive called
methylcyclopentadienyl manganese
tricarbonyl (MMT). We recommend
against the use of gasolines
containing MMT. SeeFuel Additives
on page 9‑58.
California Fuel
Requirements
If the vehicle is certified to meet
California Emissions Standards, it is
designed to operate on fuels that
meet California specifications. See
the underhood emission control
label. If this fuel is not available in
states adopting California Emissions
Standards, the vehicle will operate
satisfactorily on fuels meeting
federal specifications, but emission
control system performance might
be affected. The malfunction
indicator lamp could turn on and the
vehicle might fail a smog‐check test.
See Malfunction Indicator Lamp on
page 5‑19. If this occurs, return to
your authorized dealer for diagnosis.
If it is determined that the condition
is caused by the type of fuel used,
repairs might not be covered by the
vehicle warranty.
Fuels in Foreign
Countries
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 the vehicle
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.
Fuel 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, nothing
should have to be added to the fuel.
However, some gasolines contain
only the minimum amount of
additive required to meet U.S.
Environmental Protection Agency
Black plate (31,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
Vehicle Care 10-31
4. Replace the wiper blade.
5. Return the wiper blade assemblyto the park rest position.
Glass Replacement
If the windshield or front side glass
must be replaced, see your dealer
to determine the correct
replacement glass.
Headlamp Aiming
Headlamp aim has been preset and
should need no further adjustment.
If the vehicle is damaged in a crash,
the headlamp aim may be affected.
If adjustment to the headlamps is
necessary, see your dealer.
Bulb Replacement
For the proper type of replacement
bulbs, see Replacement Bulbs on
page 10‑33.
For any bulb‐changing procedure
not listed in this section, contact
your dealer.
Halogen Bulbs
{WARNING
Halogen bulbs have pressurized
gas inside and can burst if you
drop or scratch the bulb. You or
others could be injured. Be sure
to read and follow the instructions
on the bulb package.
Taillamps, Turn Signal,
Sidemarker, Stoplamps,
and Back-Up Lamps
If the vehicle is a Hybrid, see the
Hybrid Supplement for the bulb
changing procedure.
Black plate (79,1)GMC Yukon/Yukon XL Owner Manual - 2013 - CRC 2nd edition - 8/15/12
Vehicle Care 10-79
Notice:If the vehicle has
four-wheel drive and a different
size spare tire is installed, do not
drive in four-wheel drive until the
flat tire is repaired and/or
replaced. The vehicle could be
damaged and the repairs would
not be covered by the warranty.
Never use four-wheel drive when
a different size spare tire is
installed on the vehicle.
Your vehicle may have a different
size spare tire than the road tires
originally installed on your vehicle.
This spare tire was developed for
use on your vehicle, so it is all right
to drive on it. If your vehicle has
four-wheel drive and the different
size spare tire is installed, keep the
vehicle in two-wheel drive. After installing the spare tire on your
vehicle, you should stop as soon as
possible and make sure the spare
tire is correctly inflated. Have the
damaged or flat road tire repaired or
replaced as soon as you can and
installed back onto your vehicle.
This way, the spare tire will be
available in case you need it again.
Do not mix tires and wheels of
different sizes, because they will not
fit. Keep your spare tire and its
wheel together. If your vehicle has a
spare tire that does not match your
vehicle's original road tires and
wheels in size and type, do not
include the spare in the tire rotation.Jump Starting
For more information about the
vehicle battery, see
Battery on
page 10‑25.
If the vehicle is a Hybrid, see the
Hybrid manual for more information.
If the vehicle's battery (or batteries)
has run down, you may want to use
another vehicle and some jumper
cables to start your vehicle. Be sure
to use the following steps to do it
safely.
{WARNING
Batteries can hurt you. They can
be dangerous because:
.They contain acid that can
burn you.
.They contain gas that can
explode or ignite.
.They contain enough
electricity to burn you.
(Continued)