2004 GMC YUKON air
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Seat Position Sensors
Vehicles with dual stage air bags are also equipped with
special sensors which enable the sensing system to
monitor the position of both the driver and passenger
front seats. The seat position sensor provides
information which is used to determine if the air bags
should deploy at a reduced level or at full deployment.
Side Impact Air Bags
Your vehicle may or may not have a side impact air
bag. SeeAir Bag Systems on page 1-72. Side impact air
bags are designed to in ate in moderate to severe
side crashes. A side impact air bag will in ate if
the crash severity is above the system’s designed
“threshold level.” The threshold level can vary with
speci c vehicle design. Side impact air bags are
not designed to in ate in frontal or near-frontal impacts,
rollovers or rear impacts, because in ation would not
help the occupant. A side impact air bag will only deploy
on the side of the vehicle that is struck.
Air Bag Systems
In any particular crash, no one can say whether an air
bag should have in ated simply because of the damage
to a vehicle or because of what the repair costs were. For
frontal air bags, in ation is determined by the angle of the
impact and how quickly the vehicle slows down in frontal
and near-frontal impacts. For side impact air bags,
in ation is determined by the location and severity of the
impact.
The air bag system is designed to work properly under
a wide range of conditions, including off-road usage.
Observe safe driving speeds, especially on rough
terrain. As always, wear your safety belt. See Off-Road
Driving with Your Four-Wheel Drive Vehicle in the
Index for tips on off-road driving.
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What Makes an Air Bag In ate?
In an impact of sufficient severity, the air bag sensing
system detects that the vehicle is in a crash. For both
frontal and side impact air bags, the sensing system
triggers a release of gas from the in ator, which in ates
the air bag. The in ator, the air bag and related hardware
are all part of the air bag modules. Frontal air bag
modules are located inside the steering wheel and
instrument panel. For vehicles with side impact air bags,
the air bag modules are located in the seatback closest to
the driver’s and/or right front passenger’s door.
How Does an Air Bag 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. The air bag supplements the protection
provided by safety belts. Air bags distribute the force of
the impact more evenly over the occupant’s upper
body, stopping the occupant more gradually. But the
frontal air bags would not help you in many types
of collisions, including rollovers, rear impacts, and many
side impacts, primarily because an occupant’s motion
is not toward the air bag. Side impact air bags would not
help you in many types of collisions, including frontal
or near frontal collisions, rollovers, and rear impacts,
primarily because an occupant’s motion is not toward
those air bags. Air bags should never be regarded
as anything more than a supplement to safety belts, and
then only in moderate to severe frontal or near-frontal
collisions for the driver’s and right front passenger’s
frontal air bags, and only in moderate to severe
side collisions for vehicles with a driver’s and right front
passenger’s side impact air bag.
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What Will You See After an Air Bag
In ates?
After the air bag in ates, it quickly de ates, so quickly
that some people may not even realize the air bag
in ated. Some components of the air bag module will be
hot for a short time. These components include the
steering wheel hub for the driver’s frontal air bag and the
instrument panel for the right front passenger’s frontal
air bag. For vehicles with side impact air bags, the side
of the seatback closest to the driver’s and/or right
front passenger’s door will be hot. The parts of the bag
that come into contact with you may be warm, but
not too hot to touch. There will be some smoke and dust
coming from the vents in the de ated air bags. Air
bag in ation doesn’t prevent the driver from seeing or
being able to steer the vehicle, nor does it stop
people from leaving the vehicle.
{CAUTION:
When an air bag in ates, there is 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
can’t get out of the vehicle after an air bag
in ates, then get fresh air by opening a
window or a door. If you experience breathing
problems following an air bag deployment, you
should seek medical attention.
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In many crashes severe enough to in ate an air bag,
windshields are broken by vehicle deformation.
Additional windshield breakage may also occur from the
right front passenger air bag.
Air bags are designed to in ate only once. After an
air bag in ates, you’ll need some new parts for
your air bag system. If you don’t get them, the air
bag system won’t be there to help protect you
in another crash. A new system will include air bag
modules and possibly other parts. The service
manual for your vehicle covers the need to replace
other parts.
Your vehicle is equipped with electronic frontal
sensors which help the sensing system distinguish
between a moderate and a more severe frontal
impact. Your vehicle is also equipped with a crash
sensing and diagnostic module, which records
information about the frontal air bag system. The
module records information about the readiness of
the system and when the system commands air
bag in ation. It records the status of the driver’s
safety belt usage in a crash in which the air
bag deploys or a crash in which the air bag nearly
deploys. The module also records speed, engine
rpm, brake and throttle data.
Let only quali ed technicians work on your air bag
systems. Improper service can mean that an air
bag system won’t work properly. See your dealer for
service.
Notice:If you damage the covering for the driver’s
or the right front passenger’s air bag, or the air
bag covering on the driver’s and right front
passenger’s seatback, the bag may not work
properly. You may have to replace the air bag
module in the steering wheel, both the air bag
module and the instrument panel for the right front
passenger’s air bag, or both the air bag module
and seatback for the driver’s and right front
passenger’s side impact air bag. Do not open or
break the air bag coverings.
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Passenger Sensing System
If your rearview mirror has one of the indicators pictured
in the following illustrations, your vehicle has a passenger
sensing system. The indicator will be visible when you
turn your ignition key to START or RUN. The words ON
and OFF or the symbol for on and off, will be visible on
the rearview mirror 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 Air Bag Status Indicator on
page 3-43. If your rearview mirror does not have either of
the indicators pictured, then your vehicle does not have
the passenger sensing system.The passenger sensing system will turn off the right
front passenger’s frontal air bag under certain
conditions. The driver’s air bag and the side air bags
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 and safety
belt. The sensors are designed to detect the presence of
a properly-seated occupant and determine if the
passenger’s frontal air bag should be enabled (may
in ate) or not.
Accident statistics show that children are safer if they
are restrained in the rear rather than the front seat.
General Motors recommends that child restraints
be secured in a rear seat, including an infant riding in a
rear-facing infant seat, a child riding in a forward-facing
child seat and an older child riding in a booster seat.
Your vehicle has a rear seat that will accommodate
a rear-facing child restraint. 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 air bag deploys. Passenger Air Bag Status Indicator – United States
Passenger Air
Bag Status
Indicator – Canada
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{CAUTION:
A child in a rear-facing child restraint can be
seriously injured or killed if the right front
passenger’s air bag in ates. This is because
the back of the rear-facing child restraint
would be very close to the in ating air bag.
Even though the passenger sensing system is
designed to turn off the passenger’s frontal air
bag if the system detects a rear-facing child
restraint, no system is fail-safe, and no one can
guarantee that an air bag will not deploy under
some unusual circumstance, even though it is
turned off. General Motors recommends that
rear-facing child restraints be secured in the
rear seat, even if the air bag is off.The passenger sensing system is designed to turn off
the right front passenger’s frontal air bag 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 forward-facing 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 air bag
system or the passenger sensing system.
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When the passenger sensing system has turned off the
passenger’s frontal air bag, the off indicator will light
and stay lit to remind you that the air bag is off.
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
toSecuring a Child Restraint in the Right Front
Seat Position on page 1-68.
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.
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.The passenger sensing system is designed to enable
(may in ate) the right front passenger’s frontal air
bag 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
air bag to be enabled, the on indicator will light and stay
lit to remind you that the air bag 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 air bag, 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 air bag
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 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 about two
minutes. This will allow the system to detect that person
and then enable the passenger’s air bag.
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{CAUTION:
If the air bag readiness light in the instrument
panel cluster ever comes on and stays on, it
means that something may be wrong with the
air bag system.
CAUTION: (Continued)
CAUTION: (Continued)
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 frontal air bag. See “Air
Bag Readiness Light” in the Index for more on
this, including important safety information.
Aftermarket equipment, such as seat covers, can affect
how well the passenger sensing system operates.
You may want to consider not using seat covers or other
aftermarket equipment if your vehicle has the passenger
sensing system. SeeAdding Equipment to Your Air
Bag-Equipped Vehicle on page 1-86for more
information about modi cations 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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