belt GMC ENVOY XL 2004 Service Manual

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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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.
1-60

Doors and Locks
{CAUTION:
Unlocked doors can be dangerous.
Passengers — especially children — can
easily open the doors and fall out of a
moving vehicle. When a door is locked,
the handle will not open it. You increase
the chance of being thrown out of the
vehicle in a crash if the doors are not
locked. So, wear safety belts properly
and lock the doors whenever you drive.
Young children who get into unlocked
vehicles may be unable to get out. A child
can be overcome by extreme heat and can
suffer permanent injuries or even death
from heat stroke. Always lock your vehicle
whenever you leave it.
CAUTION: (Continued)
CAUTION: (Continued)

Outsiders can easily enter through an
unlocked door when you slow down or
stop your vehicle. Locking your doors can
help prevent this from happening.
There are several ways to lock and unlock your vehicle.
You can use the remote keyless entry system.
You can use your key to unlock your door from the
outside.
2-8

Instrument Panel Overview...............................3-4
Hazard Warning Flashers................................3-6
Other Warning Devices...................................3-6
Horn.............................................................3-7
Tilt Wheel.....................................................3-7
Turn Signal/Multifunction Lever.........................3-7
Exterior Lamps.............................................3-16
Interior Lamps..............................................3-18
Accessory Power Outlets...............................3-21
Ashtrays and Cigarette Lighter........................3-21
Climate Controls............................................3-22
Dual Climate Control System..........................3-22
Dual Automatic Climate Control System...........3-25
Rear Climate Control System.........................3-31
Climate Controls Personalization.....................3-34
Warning Lights, Gages, and Indicators............3-35
Instrument Panel Cluster................................3-36
Speedometer and Odometer...........................3-37
Tachometer.................................................3-37
Safety Belt Reminder Light.............................3-38
Air Bag Readiness Light................................3-38
Charging System Light..................................3-39Voltmeter Gage............................................3-40
Brake System Warning Light..........................3-40
Anti-Lock Brake System Warning Light.............3-42
Engine Coolant Temperature Gage..................3-42
Malfunction Indicator Lamp.............................3-43
Oil Pressure Gage........................................3-46
Change Engine Oil Light................................3-47
Security Light...............................................3-47
Cruise Control Light......................................3-48
Reduced Engine Power Light.........................3-48
Service Four-Wheel Drive Warning Light..........3-48
Check Gages Warning Light...........................3-49
Gate Ajar Light.............................................3-49
Fuel Gage...................................................3-50
Low Fuel Warning Light.................................3-50
Driver Information Center (DIC).......................3-51
DIC Operation and Displays...........................3-51
DIC Warnings and Messages.........................3-60
Audio System(s).............................................3-64
Setting the Time...........................................3-64
Radio with CD..............................................3-65
Radio with Cassette and CD..........................3-76
Section 3 Instrument Panel
3-1

Safety Belt Reminder Light
When the key is turned to RUN, a chime will come on
for several seconds to remind people to fasten their
safety belts, unless the driver’s safety belt is already
buckled.
The safety belt light will
also come on and stay
on for several seconds,
then it will ash for
several more.
If the driver’s belt is already buckled, neither the chime
nor the light will come on.
Air Bag Readiness Light
There is an air bag readiness light on the instrument
panel, which shows the air bag symbol. The system
checks the air bag’s electrical system for malfunctions.
The light tells you if there is an electrical problem.
The system check includes the air bag sensors, the air
bag modules, the wiring and the crash sensing and
diagnostic module. For more information on the air bag
system, seeAir Bag Systems on page 1-49.
This light will come on
when you start your
vehicle, and it will ash
for a few seconds.
Then the light should
go out. This means the
system is ready.
If the air bag readiness light stays on after you start
the vehicle or comes on when you are driving, your air
bag system may not work properly. Have your vehicle
serviced right away.
3-38

{CAUTION:
If the air bag readiness light stays on after you
start your vehicle, it means the air bag system
may not be working properly. The air bags in
your vehicle may not inate in a crash, or they
could even inate without a crash. To help
avoid injury to yourself or others, have your
vehicle serviced right away if the air bag
readiness light stays on after you start your
vehicle.
The air bag readiness light should ash for a few
seconds when you turn the ignition key to RUN.
If the light doesn’t come on then, have it xed so it
will be ready to warn you if there is a problem.
Charging System Light
The charging system light
will come on briey when
you turn on the ignition,
but the engine is not
running, as a check to
show you it is working.
It should go out once the engine is running. If it stays
on, or comes on while you are driving, you may have
a problem with the charging system. It could indicate
that you have problems with a generator drive belt,
or another electrical problem. Have it checked
right away. Driving while this light is on could drain
your battery.
If you must drive a short distance with the light on,
be certain to turn off all your accessories, such as the
radio and air conditioner.
3-39

Care of Your Cassette Tape Player
A tape player that is not cleaned regularly can cause
reduced sound quality, ruined cassettes, or a damaged
mechanism. Cassette tapes should be stored in their
cases away from contaminants, direct sunlight, and
extreme heat. If they are not, they may not operate
properly or may cause failure of the tape player.
The tape player should be cleaned regularly after every
50 hours of use. The radio may display CLEAN to
indicate that the tape player has been used for 50 hours
without resetting the tape clean timer. If this message
appears on the display, the cassette tape player
needs to be cleaned. It will still play tapes, but it should
be cleaned as soon as possible to prevent damage
to the tapes and player. If there is a reduction in sound
quality, try a known good cassette to see if the tape
or the tape player is at fault. If this other cassette has
no improvement in sound quality, clean the tape player.
For best results, use a scrubbing action, non-abrasive
cleaning cassette with pads which scrub the tape head as
the hubs of the cleaner cassette turn. The recommended
cleaning cassette is available through your dealer.
The broken tape detection feature of the cassette
tape player may identify the cleaning cassette as a
damaged tape, in error. To prevent the cleaning cassette
from being ejected, use the following steps:1. Turn the ignition on.
2. Turn the radio off.
3. Press and hold the TAPE CD button for ve
seconds. READY will appear on the display and
a cassette symbol will ash for ve seconds.
4. Insert the scrubbing action cleaning cassette.
5. Eject the cleaning cassette after the manufacturer’s
recommended cleaning time.
After the cleaning cassette is ejected, the broken
tape detection feature will be active again.
A non-scrubbing action, wet-type cleaner which uses a
cassette with a fabric belt to clean the tape head
can be used. This type of cleaning cassette will not
eject on its own. A non-scrubbing action cleaner may not
clean as thoroughly as the scrubbing type cleaner.
The use of a non-scrubbing action, dry-type cleaning
cassette is not recommended.
After the player is cleaned, press and hold the EJT
button for ve seconds to reset the CLEAN indicator.
The radio will display CLEANED to show the indicator
was reset.
Cassettes are subject to wear and the sound quality may
degrade over time. Always make sure the cassette tape
is in good condition before the tape player is serviced.
3-121

Your Driving, the Road, and
Your Vehicle
Defensive Driving
The best advice anyone can give about driving is: Drive
defensively.
Please start with a very important safety device in your
vehicle: Buckle up. SeeSafety Belts: They Are for
Everyone on page 1-8.
Defensive driving really means “be ready for anything.”
On city streets, rural roads or freeways, it means
“always expect the unexpected.”
Assume that pedestrians or other drivers are going to
be careless and make mistakes. Anticipate what
they might do. Be ready for their mistakes.
Rear-end collisions are about the most preventable of
accidents. Yet they are common. Allow enough following
distance. It is the best defensive driving maneuver, in
both city and rural driving. You never know when the
vehicle in front of you is going to brake or turn suddenly.
Defensive driving requires that a driver concentrate on
the driving task. Anything that distracts from the driving
task — such as concentrating on a cellular telephone call,
reading, or reaching for something on the oor — makesproper defensive driving more difficult and can even
cause a collision, with resulting injury. Ask a passenger to
help do things like this, or pull off the road in a safe place
to do them yourself. These simple defensive driving
techniques could save your life.Drunken Driving
Death and injury associated with drinking and driving is
a national tragedy. It is the number one contributor
to the highway death toll, claiming thousands of victims
every year.
Alcohol affects four things that anyone needs to drive
a vehicle:
Judgment
Muscular Coordination
Vision
Attentiveness.
Police records show that almost half of all motor
vehicle-related deaths involve alcohol. In most cases,
these deaths are the result of someone who was
drinking and driving. In recent years, more than
16,000 annual motor vehicle-related deaths have been
associated with the use of alcohol, with more than
300,000 people injured.
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