GMC ENVOY XL 2004 Repair Manual

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.
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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.
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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.
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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.
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Servicing Your Air Bag-Equipped
Vehicle
Air bags affect how your vehicle should be serviced.
There are parts of the air bag systems in several places
around your vehicle. Your dealer and the service manual
have information about servicing your vehicle and the
air bag systems. To purchase a service manual, see
Service Publications Ordering Information on page 7-12.
{CAUTION:
For up to 10 minutes after the ignition key is
turned off and the battery is disconnected,
an air bag can still inate during improper
service. You can be injured if you are close
to an air bag when it inates. Avoid yellow
connectors. They are probably part of the air
bag system. Be sure to follow proper service
procedures, and make sure the person
performing work for you is qualied to do so.
The air bag systems do not need regular maintenance.
Restraint System Check
Checking Your Restraint Systems
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.
Also look for any opened or broken air bag covers,
and have them repaired or replaced. (The air bag
system does not need regular maintenance.)
1-59

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’ve had a crash, do you need new belts or
LATCH system parts?
After a very minor collision, nothing may be necessary.
But if the belts were stretched, as they would be if
worn during a more severe crash, then you need
new parts.
If the LATCH system was being used during a more
severe crash, you may need new LATCH system parts.
If belts are cut or damaged, replace them. Collision
damage also may mean you will need to have LATCH
system, safety belt or seat parts repaired or replaced.
New parts and repairs may be necessary even if the belt
or LATCH system wasn’t being used at the time of
the collision.
If an air bag inates, you’ll need to replace air bag
system parts. See the part on the air bag system
earlier in this section.
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Keys...............................................................2-3
Remote Keyless Entry System.........................2-5
Remote Keyless Entry System Operation...........2-6
Doors and Locks.............................................2-8
Power Door Locks..........................................2-9
Delayed Locking...........................................2-10
Programmable Automatic Door Locks..............2-10
Rear Door Security Locks..............................2-13
Lockout Protection........................................2-13
Leaving Your Vehicle....................................2-13
Liftgate/Liftglass............................................2-14
Windows........................................................2-15
Power Windows............................................2-16
Sun Visors...................................................2-17
Theft-Deterrent Systems..................................2-17
Content Theft-Deterrent.................................2-17
Passlock
®....................................................2-19
Starting and Operating Your Vehicle................2-19
New Vehicle Break-In....................................2-19
Ignition Positions..........................................2-20Starting Your Engine.....................................2-21
Adjustable Throttle and Brake Pedal................2-22
Engine Coolant Heater..................................2-23
Automatic Transmission Operation...................2-24
Four-Wheel Drive..........................................2-26
Parking Brake..............................................2-29
Shifting Into Park (P).....................................2-31
Shifting Out of Park (P).................................2-33
Parking Over Things That Burn.......................2-33
Engine Exhaust............................................2-34
Running Your Engine While
You Are Parked........................................2-34
Mirrors...........................................................2-36
Automatic Dimming Rearview Mirror
with OnStar
®and Compass........................2-36
Outside Manual Mirrors..................................2-38
Outside Power Mirrors...................................2-38
Outside Curb View Assist Mirrors....................2-39
Outside Convex Mirror...................................2-39
Outside Heated Mirrors..................................2-39
Section 2 Features and Controls
2-1

OnStar®System.............................................2-40
HomeLink®Transmitter...................................2-42
Programming the HomeLink®Transmitter.........2-43
Storage Areas................................................2-46
Glove Box...................................................2-46
Overhead Console........................................2-46
Front Storage Area.......................................2-47
Luggage Carrier...........................................2-48Rear Storage Area........................................2-49
Rear Floor Storage Lid..................................2-51
Convenience Net..........................................2-51
Cargo Cover................................................2-52
Sunroof.........................................................2-53
Vehicle Personalization...................................2-53
Memory Seat...............................................2-53
Section 2 Features and Controls
2-2

Keys
{CAUTION:
Leaving children in a vehicle with the ignition
key is dangerous for many reasons. They could
operate the power windows or other controls or
even make the vehicle move. The children or
others could be badly injured or even killed.
Do not leave the keys in a vehicle with children.
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This vehicle has one
double-sided key for the
ignition and door lock.
It will t with either
side up.
When a new vehicle is delivered, the dealer provides
the owner with a pair of identical keys and a key
code number.The key code number tells your dealer or a qualied
locksmith how to make extra keys. Keep this number
in a safe place. If you lose your keys, you’ll be able
to have new ones made easily using this number.
Your selling dealer should also have this number.
Notice:If you ever lock your keys in your vehicle,
you may have to damage the vehicle to get in.
Be sure you have spare keys.
If you ever do get locked out of your vehicle, call the
GM Roadside Assistance Center. SeeRoadside
Assistance Program on page 7-7.
If your vehicle is equipped with the OnStar
®system
with an active subscription and you lock your keys inside
the vehicle, OnStar
®may be able to send a command
to unlock your vehicle. SeeOnStar®System on
page 2-40for more information.
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