2004 GMC ENVOY XL Owners Manual

{CAUTION:
Both frontal and side impact air bags inate
with great force, faster than the blink of an
eye. If you are too close to an inating air bag,
as you would be if you were leaning forward,
it could seriously injure you. Safety belts
help keep you in position for air bag ination
before and during a crash. Always wear
your safety belt, even with frontal air bags.
The driver should sit as far back as possible
while still maintaining control of the vehicle.
Front occupants should not lean on or sleep
against the door.
{CAUTION:
Anyone who is up against, or very close to,
any air bag when it inates can be seriously
injured or killed. Air bags plus lap-shoulder
belts offer the best protection for adults, but
not for young children and infants. Neither the
vehicle’s safety belt system nor its air bag
system is designed for them. Young children
and infants need the protection that a child
restraint system can provide. Always secure
children properly in your vehicle. To read how,
see the part of this manual called “Older
Children” or “Infants and Young Children.”
1-51

There is an air bag
readiness light on the
instrument panel cluster,
which shows the air
bag symbol.
The system checks the air bag electrical system for
malfunctions. The light tells you if there is an electrical
problem. SeeAir Bag Readiness Light on page 3-38
for more information.Where Are the Air Bags?
The driver’s frontal air bag is in the middle of the
steering wheel.
1-52

The right front passenger’s frontal air bag is in the
instrument panel on the passenger’s side.If your vehicle has a driver’s side impact air bag it is
located in the side of the driver’s seatback closest to
the door.
1-53

If your vehicle has a right front passenger’s side impact
air bag it is located in the side of the passenger’s
seatback closest to the door.
{CAUTION:
If something is between an occupant and an
air bag, the bag might not inate properly or it
might force the object into that person causing
severe injury or even death. The path of an
inating air bag must be kept clear. Do not put
anything between an occupant and an air bag,
and do not attach or put anything on the
steering wheel hub or on or near any other air
bag covering. Do not let seat covers block the
ination path of a side impact air bag.
1-54

When Should an Air Bag Inate?
The driver’s and right front passenger’s frontal air bags
are designed to inate in moderate to severe frontal
or near-frontal crashes. But they are designed to inate
only if the impact speed is above the system’s
designed “threshold level.”
In addition, your vehicle has “dual stage” frontal air bags,
which adjust the amount of restraint according to crash
severity. For moderate frontal impacts, these air bags
inate at a level less than full deployment. For more
severe frontal impacts, full deployment occurs. If the front
of your vehicle goes straight into a wall that doesn’t move
or deform, the threshold level for the reduced deployment
is about 12 to 16 mph (19 to 26 km/h), and the threshold
level for a full deployment is about 16 to 25 mph
(26 to 40 km/h). The threshold level can vary, however,
with specic vehicle design, so that it can be somewhat
above or below this range.
If your vehicle strikes something that will move or
deform, such as a parked car, the threshold level will be
higher. The driver’s and right front passenger’s frontal
air bags are not designed to inate in rollovers, rear
impacts, or in many side impacts because ination
would not help the occupant.Your vehicle may or may not have a side impact air
bag. See Air Bag Systems in the Index. Side impact air
bags are designed to inate in moderate to severe
side crashes. A side impact air bag will inate if
the crash severity is above the system’s designed
“threshold level.” The threshold level can vary with
specic vehicle design. Side impact air bags are
not designed to inate in frontal or near-frontal impacts,
rollovers or rear impacts, because ination would not
help the occupant. A side impact air bag will only deploy
on the side of the vehicle that is struck.
In any particular crash, no one can say whether an air
bag should have inated simply because of the damage
to a vehicle or because of what the repair costs were.
For frontal air bags, ination 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, ination 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. SeeOff-Road
Driving with Your Four-Wheel-Drive Vehicle on
page 4-16for tips on off-road driving.
1-55

What Makes an Air Bag Inate?
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 inator,
which inates the air bag. The inator, 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.
1-56

What Will You See After an Air Bag
Inates?
After the air bag inates, it quickly deates, so quickly
that some people may not even realize the air bag
inated. 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 deated air bags. Air bag ination 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 inates, 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 not get out of the vehicle after an
air bag inates, 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.
Your vehicle has a feature that will automatically unlock
the doors and turn the interior lamps on when the air
bags inate (if battery power is available). You can lock
the doors again and turn the interior lamps off by
using the door lock and interior lamp controls.
1-57

In many crashes severe enough to inate 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 inate only once. After
an air bag inates, 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 frontal impact 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, when the system
commands air bag ination and driver’s safety belt
usage at deployment. The module also records
speed, engine rpm, brake and throttle data.
Let only qualied 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 air 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.
1-58