page 5 GMC ENVOY 2008 Owner's Guide

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 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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{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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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). SeePassenger Sensing
System on page 1-61.
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.
SeeCustomer Satisfaction Procedure on page 7-2.
If your vehicle has rollover roof-rail airbags, see
Different Size Tires and Wheels on page 5-76
for additional important information.Q:Because I have a disability, I have to get my
vehicle modied. How can I nd out whether
this will affect my airbag system?
A:If you have questions, call Customer Assistance.
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 7-2.
In addition, your dealer/retailer and the service manual
have information about the location of the airbag sensors,
sensing and diagnostic module and airbag wiring.
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Restraint System Check
Checking the Restraint Systems
Safety Belts
Now and then, make sure the safety belt reminder light
and all your belts, buckles, latch plates, retractors
and anchorages are working properly.
Look for any other loose or damaged safety belt system
parts. If you see anything that might keep a safety belt
system from doing its job, have it repaired. Torn or frayed
safety belts may not protect you in a crash. They can rip
apart under impact forces. If a belt is torn or frayed, get a
new one right away.
Make sure the safety belt reminder light is working.
SeeSafety Belt Reminders on page 3-32for more
information.
Keep safety belts clean and dry. SeeCare of Safety
Belts on page 5-103.
Airbags
The airbag system does not need regularly scheduled
maintenance or replacement. Make sure the airbag
readiness light is working. SeeAirbag Readiness
Light on page 3-33for more information.
Notice:If an airbag covering is damaged, opened,
or broken, the airbag may not work properly.
Do not open or break the airbag coverings. If there
are any opened or broken airbag covers, have
the airbag covering and/or airbag module replaced.
For the location of the airbag modules, seeWhat
Makes an Airbag Inflate? on page 1-59.
See your dealer/retailer for service.
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Replacing Restraint System Parts
After a Crash
{CAUTION:
A crash can damage the restraint systems in
your vehicle. A damaged restraint system may
not properly protect the person using it,
resulting in serious injury or even death in
a crash. To help make sure your restraint
systems are working properly after a crash,
have them inspected and any necessary
replacements made as soon as possible.If you have had a crash, do you need new belts or
LATCH system (if equipped) parts?
After a very minor crash, nothing may be necessary.
But the belt assemblies that were used during any crash
may have been stressed or damaged. See your dealer/
retailer to have your safety belt assemblies inspected or
replaced.
If your vehicle has the LATCH system and it was being
used during a crash, you may need new LATCH
system parts.
New parts and repairs may be necessary even if the
belt or LATCH system (if equipped), was not being used
at the time of the crash.
If an airbag inates, you will need to replace airbag
system parts. See the part on the airbag system earlier
in this section.
Have your safety belt pretensioners checked if your
vehicle has been in a crash, if your airbag readiness
light stays on after you start your vehicle, or while you
are driving. SeeAirbag Readiness Light on page 3-33.
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