GMC ENVOY DENALI 2008 Repair Manual

The roof-rail airbags for the driver, right front passenger,
and second row outboard passengers are in the
ceiling above the side windows.
{CAUTION:
If something is between an occupant and an
airbag, the airbag might not inate properly
or it might force the object into that person
causing severe injury or even death. The path
of an inating airbag must be kept clear.
Do not put anything between an occupant and
an airbag, and do not attach or put anything
on the steering wheel hub or on or near any
other airbag covering.
If your vehicle has roof-rail airbags, never
secure anything to the roof of your vehicle by
routing the rope or tie down through any door
or window opening. If you do, the path of an
inating roof-rail airbag will be blocked. Driver Side shown, Passenger Side similar
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When Should an Airbag Inate?
Frontal airbags are designed to inate in moderate to
severe frontal or near-frontal crashes to help reduce the
potential for severe injuries mainly to the driver’s or right
front passenger’s head and chest. However, they are only
designed to inate if the impact exceeds a predetermined
deployment threshold. Deployment thresholds are used
to predict how severe a crash is likely to be in time for the
airbags to inate and help restrain the occupants.
Whether your frontal airbags will or should deploy is not
based on how fast your vehicle is traveling. It depends
largely on what you hit, the direction of the impact,
and how quickly your vehicle slows down.
Frontal airbags may inate at different crash speeds.
For example:
If the vehicle hits a stationary object, the airbags
could inate at a different crash speed than if the
vehicle hits a moving object.
If the vehicle hits an object that deforms, the
airbags could inate at a different crash speed than
if the vehicle hits an object that does not deform.
If the vehicle hits a narrow object (like a pole), the
airbags could inate at a different crash speed
than if the vehicle hits a wide object (like a wall).
If the vehicle goes into an object at an angle, the
airbags could inate at a different crash speed
than if the vehicle goes straight into the object.Thresholds can also vary with specic vehicle design.
Frontal airbags are not intended to inate during vehicle
rollovers, rear impacts, or in many side impacts.
In addition, your vehicle has dual-stage frontal airbags.
Dual-stage airbags adjust the restraint according to
crash severity. Your vehicle has electronic frontal
sensors, which help the sensing system distinguish
between a moderate frontal impact and a more severe
frontal impact. For moderate frontal impacts, dual-stage
airbags inate at a level less than full deployment.
For more severe frontal impacts, full deployment occurs.
Your vehicle has seat position sensors which enables
the sensing system to monitor the position of the driver’s
and right front passenger’s seat. The sensors provide
information that is used to determine if the airbags
should deploy at a reduced level or at full deployment.
Your vehicle has roof-rail airbags. SeeAirbag System
on page 1-53. Roof-rail airbags are intended to inate
in moderate to severe side crashes. In addition,
these roof-rail airbags are intended to inate during a
rollover. Roof-rail airbags will inate if the crash severity
is above the system’s designed threshold level. The
threshold level can vary with specic vehicle design.
Roof-rail airbags are not intended to inate in frontal
impacts, near-frontal impacts, or rear impacts.
Both roof-rail airbags will deploy when either side
of the vehicle is struck or if the sensing system
predicts that the vehicle is about to roll over.
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In any particular crash, no one can say whether an
airbag should have inated simply because of the
damage to a vehicle or because of what the repair
costs were. For frontal airbags, ination is determined
by what the vehicle hits, the angle of the impact,
and how quickly the vehicle slows down. For 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 Inate?
In a deployment event, the sensing system sends
an electrical signal triggering a release of gas from
the inator. Gas from the inator lls the airbag causing
the bag to break out of the cover and deploy. The
inator, 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 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. 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 rst and second rows.
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. SeeWhen Should an Airbag Inflate? on
page 1-58for more information.
Airbags should never be regarded as anything more
than a supplement to safety belts.
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What Will You See After an Airbag
Inates?
After the frontal airbags inate, they quickly deate,
so quickly that some people may not even realize
an airbag inated. Roof-rail airbags may still be at
least partially inated for some time after they deploy.
Some components of the airbag module may be hot for
several minutes. For location of the airbag modules,
seeWhat Makes an Airbag Inflate? on page 1-59.
The parts of the airbag that come into contact with you
may be warm, but not too hot to touch. There may be
some smoke and dust coming from the vents in the
deated airbags. Airbag ination does not prevent the
driver from seeing out of the windshield or being able to
steer the vehicle, nor does it prevent people from leaving
the vehicle.
{CAUTION:
When an airbag inates, there may be dust
in the air. This dust could cause breathing
problems for people with a history of asthma or
other breathing trouble. To avoid this, everyone
in the vehicle should get out as soon as it is
safe to do so. If you have breathing problems
but cannot get out of the vehicle after an airbag
inates, then get fresh air by opening a window
or a door. If you experience breathing problems
following an airbag deployment, you should
seek medical attention.
Your vehicle has a feature that may automatically
unlock the doors, turn the interior lamps on, and turn
the hazard warning ashers on when the airbags inate.
You can lock the doors, turn the interior lamps off,
and turn the hazard warning ashers off by using the
controls for those features.
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In many crashes severe enough to inate the airbag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur
from the right front passenger airbag.
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 7-18andEvent Data Recorders on page 7-18.
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 in the rearview
mirror 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 3-34. United States
Canada
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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.
The passenger sensing system works with sensors
that are part of the right front passenger’s seat.
The sensors are designed to detect the presence
of a properly-seated occupant and determine if the
right front passenger’s frontal airbag should be enabled
(may inate) or not.
Accident statistics show that children are safer if they
are restrained in the rear rather than the front seat.
We recommend that children 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.
{CAUTION:
A child in a rear-facing child restraint can be
seriously injured or killed if the right front
passenger’s airbag inates. This is because
the back of the rear-facing child restraint
would be very close to the inating airbag.
Even though the passenger sensing system is
designed to turn off the right front passenger’s
frontal airbag if the system detects a
rear-facing child restraint, no system is
fail-safe, and no one can guarantee that an
airbag will not deploy under some unusual
circumstance, even though it is turned off. We
recommend that rear-facing child restraints be
secured 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.
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The passenger sensing system is designed to turn off
the right front passenger’s frontal airbag if:
The right front passenger seat is unoccupied.
The system determines that an infant is present in
a rear-facing infant seat.
The system determines that a small child is present
in a child restraint.
The system determines that a small child is present
in a booster seat.
A right front passenger takes his/her weight off of
the seat for a period of time.
The right front passenger seat is occupied by a
smaller person, such as a child who has outgrown
child restraints.
Or, if there is a critical problem with the airbag
system or the passenger sensing system.
When the passenger sensing system has turned off the
right front passenger’s frontal airbag, the off indicator
will light and stay lit to remind you that the airbag is off.
SeePassenger Airbag Status Indicator on page 3-34.If a child restraint has been installed and the on indicator
is lit, turn the vehicle off. Remove the child restraint from
the vehicle and reinstall the child restraint following the
child restraint manufacturer’s directions and refer to
Securing a Child Restraint in the Right Front Seat
Position on page 1-50.
If, after reinstalling the child restraint and restarting the
vehicle, the on indicator is still lit, check to make sure that
the vehicle’s seatback is not pressing the child restraint
into the seat cushion. If this happens, slightly recline
the vehicle’s seatback and adjust the seat cushion if
possible. Also make sure the child restraint is not trapped
under the vehicle head restraint. If this happens, adjust
the head restraint. SeeHead Restraints on page 1-10.
Remove any additional material from the seat such as
blankets, cushions, seat covers, seat heaters or seat
massagers before reinstalling or securing the child
restraint.
If the on indicator is still lit, secure the child in the child
restraint in a rear seat position in the vehicle, and
check with your dealer/retailer.
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The passenger sensing system is designed to enable
(may inate) the right front passenger’s frontal
airbag anytime the system senses that a person of adult
size is sitting properly in the right front passenger’s
seat. When the passenger sensing system has allowed
the airbag to be enabled, the on indicator will light
and stay lit to remind you that the airbag is active.
For some children who have outgrown child restraints
and for very small adults, the passenger sensing system
may or may not turn off the right front passenger’s frontal
airbag, depending upon the person’s seating posture
and body build. Everyone in your vehicle who has
outgrown child restraints should wear a safety belt
properly — whether or not there is an airbag for that
person.
If a person of adult-size is sitting in the right front
passenger’s seat, but the off indicator is lit, it could be
because that person is not sitting properly in the seat.
If this happens, turn the vehicle off, remove any additional
material from the seat, such as blankets, cushions, seat
covers, seat heaters or seat massagers and ask the
person to place the seatback in the fully upright position,
then sit upright in the seat, centered on the seat cushion,
with the person’s legs comfortably extended. Restart the
vehicle and have the person remain in this position for
two to three minutes. This will allow the system to detect
that person and then enable the right front passenger’s
frontal airbag.Safety belts help keep the passenger in position on
the seat during vehicle maneuvers and braking, which
helps the passenger sensing system maintain the
passenger airbag status. See “Safety Belts” and “Child
Restraints” in the Index for additional information
about the importance of proper restraint use.
If you ever pull the shoulder portion of the belt out all the
way, you will engage the child restraint locking feature.
This may unintentionally cause the passenger sensing
system to turn the airbag(s) off for some adult size
occupants. If this happens, just let the belt go back
all the way and start again.
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{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 3-33for more on this, including
important safety information.A thick layer of additional material, such as a blanket or
cushion, or aftermarket equipment such as seat covers,
seat heaters, and seat massagers can affect how well
the passenger sensing system operates. We recommend
that you not use seat covers or other aftermarket
equipment other than any that GM has approved for
your specic vehicle. SeeAdding Equipment to Your
Airbag-Equipped Vehicle on page 1-66for more
information about modications that can affect
how the system operates.
{CAUTION:
Stowing of articles under the passenger’s seat
or between the passenger’s seat cushion
and seatback may interfere with the proper
operation of the passenger sensing system.
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Servicing Your Airbag-Equipped
Vehicle
Airbags affect how your vehicle should be serviced.
There are parts of the airbag system in several places
around your vehicle. Your dealer/retailer and the service
manual have information about servicing your vehicle
and the airbag system. To purchase a service manual,
seeService Publications Ordering Information on
page 7-16.
{CAUTION:
For up to 10 seconds after the ignition is
turned off and the battery is disconnected, an
airbag can still inate during improper service.
You can be injured if you are close to an airbag
when it inates. Avoid yellow connectors. They
are probably part of the airbag system. Be sure
to follow proper service procedures, and make
sure the person performing work for you is
qualied to do so.
Adding Equipment to Your
Airbag-Equipped Vehicle
Q:Is there anything I might add to or change
about the vehicle that could keep the airbags
from working properly?
A:Yes. If you add things that change your vehicle’s
frame, bumper system, height, front end or side
sheet metal, they may 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, rearview mirror, front sensors,
rollover sensor module, or airbag wiring can
affect the operation of the airbag system.
In addition, your vehicle has 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.
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