2002 GMC YUKON XL DENALI air condition

1-46
When should an air bag inflate?
The driver's and right front passenger's frontal air bags
are designed to inflate in moderate to severe frontal or
near
-frontal crashes. But they are designed to inflate
only if the impact speed is above the system's designed
ªthreshold level.º
If your vehicle goes straight into a wall that doesn't move
or deform, the threshold level is about 9 to 16 mph
(14 to 26 km/h). The threshold level can vary, however,
with specific 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 inflate in rollovers, rear
impacts, or in many side impacts because inflation
would not help the occupant.
The side impact air bags are designed to inflate in
moderate to severe side crashes. A side impact air bag
will inflate if the crash severity is above the system's
designed ªthreshold level.º The threshold level can vary
with specific vehicle design. Side impact air bags are not
designed to inflate in frontal or near
-frontal impacts,
rollovers or rear impacts, because inflation 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 inflated simply because of the damage
to a vehicle or because of what the repair costs were. For
frontal air bags, inflation 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, inflation 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 ªOff
-Road
Drivingº in the Index for more tips on off
-road driving.
What makes an air bag inflate?
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 inflator, which inflates
the air bag. The inflator, air bag and related hardware
are all part of the air bag modules inside the steering
wheel, instrument panel and the side of the front
seatbacks closest to the door.

2-29
CAUTION:
It can be dangerous to get out of your vehicle if
the shift lever is not fully in PARK (P) with the
parking brake firmly set. Your vehicle can roll.
Don't leave your vehicle when the engine is
running unless you have to. If you've left the
engine running, the vehicle can move suddenly.
You or others could be injured. To be sure your
vehicle won't move, even when you're on fairly
level ground, always set your parking brake and
move the shift lever to PARK (P).
Follow the proper steps to be sure your vehicle won't
move. See ªShifting Into PARK (P)º in the Index.
If you're pulling a trailer, see ªTowing a Trailerº in
the Index.
Autoride

The Autoride
feature provides superior vehicle
ride and handling under a variety of passenger and
loading conditions.
The system is fully automatic and uses a computer
controller to continuously monitor vehicle speed, wheel
to body position, lift/dive and steering position of the
vehicle. The controller then sends signals to each shock
absorber to independently adjust the damping level to
provide the optimum vehicle ride.
Autoride also interacts with the tow/haul mode that,
when activated, will provide additional control of the
shock absorbers. This additional control results in better
ride and handling characteristics when the vehicle is
loaded or towing a trailer. See ªTow/Haul Modeº in the
Index for more information.

2-67
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 inflate in a crash, or they
could even inflate 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 flash for a few
seconds when you turn the ignition key to RUN. If the
light doesn't come on then, have it fixed so it will be
ready to warn you if there is a problem.
Voltmeter
United States Canada
When your engine is not running, but the ignition is in
RUN, this gage shows your battery's state of charge in
DC volts.
When the engine is running, the gage shows the
condition of the charging system. Readings between
the low and high warning zones indicate the normal
operating range.

2-73
This light should come on, as a check to show you it is
working, when the ignition is on and the engine is not
running. If the light doesn't come on, have it repaired.
This light will also come on during a malfunction in
one of two ways:

Light Flashing
-- A misfire condition has been
detected. A misfire increases vehicle emissions and
may damage the emission control system on your
vehicle. Dealer or qualified service center diagnosis
and service may be required.

Light On Steady
-- An emission control system
malfunction has been detected on your vehicle.
Dealer or qualified service center diagnosis and
service may be required.
If the Light Is Flashing
The following may prevent more serious damage to
your vehicle:

Reducing vehicle speed.

Avoiding hard accelerations.

Avoiding steep uphill grades.

If you are towing a trailer, reduce the amount of
cargo being hauled as soon as it is possible.If the light stops flashing and remains on steady, see
ªIf the Light Is On Steadyº following.
If the light continues to flash, when it is safe to do so,
stop the vehicle. Find a safe place to park your vehicle.
Turn the key off, wait at least 10 seconds and restart the
engine. If the light remains on steady, see ªIf the Light
Is On Steadyº following. If the light is still flashing,
follow the previous steps, and drive the vehicle to your
dealer or qualified service center for service.
If the Light Is On Steady
You may be able to correct the emission system
malfunction by considering the following:
Did you recently put fuel into your vehicle?
If so, reinstall the fuel cap, making sure to fully install
the cap. See ªFilling Your Tankº in the Index. The
diagnostic system can determine if the fuel cap has been
left off or improperly installed. A loose or missing fuel
cap will allow fuel to evaporate into the atmosphere. A
few driving trips with the cap properly installed should
turn the light off.

2-77
Here are some situations you may experience with
your fuel gage. None of these indicate a problem with
the fuel gage.

At the gas station, the fuel pump shuts off before the
gage reads full.

It takes a little more or less fuel to fill up than the
fuel gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank's capacity to fill
the tank.

The gage goes back to empty when you turn off
the ignition.
Message Center
The message center is located on the left side of the
instrument panel cluster. It gives you important safety
and maintenance facts. When you turn the ignition on,
the entire center lights up for just a few seconds. As
needed, the message center will display one of the
following messages. The message center is capable of
alternating among different messages if needed.
Battery
If this message is displayed
when the engine is running,
you may have a problem
with your charging system.
The battery display will also stay on while the key is in
RUN until the engine is started.
If the message stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this message displayed could drain
your battery.
If you must drive a short distance with this message
displayed, it helps to turn off all your accessories, such
as the radio and the air conditioner.

2-80 Low Coolant
This message is displayed
when the cooling system is
low on coolant.
The engine may overheat. See ªEngine Coolantº in
the Index and have your vehicle serviced as soon as
you can.
Check Coolant Temp
This message is displayed
when the cooling system
temperature gets hot.
Check the coolant temperature gage and the coolant
level. See ªEngine Coolant,º ªEngine Coolant
Temperature Gageº and ªEngine Overheatingº in the
Index for further information.
Engine Overheated
This message is displayed
when the cooling system
temperature gets too hot.
This message will be displayed after the air conditioning
system has automatically turned off for the engine
coolant protection mode. See ªEngine Overheatingº in
the Index for further information.
Reduced Engine Power
This message is displayed
when the cooling system
temperature gets too hot
and the engine further
enters the engine coolant
protection mode.
See ªEngine Overheatingº in the Index for
further information.

3-
3-1
Section 3 Comfort Controls and Audio Systems
In this section, you'll find out how to operate the comfort control and audio systems offered with your vehicle.
Be sure to read about the particular systems supplied with your vehicle.
3
-2 Comfort Controls
3
-2 Electronic Climate Control System
3
-8 Air Conditioning
3
-8 Heating
3
-9 Defogging and Defrosting
3
-9 Rear Window Defogger
3
-10 Ventilation System
3
-11 Audio Systems
3
-11 Setting the Clock
3
-12 AM-FM Stereo with Cassette Tape
Player (Bose
)3
-17 Rear Seat Audio (RSA)
3
-19 Compact Disc Changer
3
-22 Theft-Deterrent Feature
3
-24 Audio Steering Wheel Controls
3
-25 Understanding Radio Reception
3
-25 Tips About Your Audio System
3
-26 Care of Your Cassette Tape Player
3
-27 Care of Your Compact Discs
3
-27 Care of Your Compact Disc Player
3
-27 Fixed Mast Antenna

3-3
Mode Knob - Manual Operation
The right knob on the control panel allows you to
choose the direction of air delivery.
You can choose to set the climate control system
operations manually, or let the system work
automatically by turning the knob on the control panel
to AUTO. See ªMode Knob
-- Automatic Operationº
later in this section.
(Vent): This setting directs most of the air through
the instrument panel outlets and a small amount through
the floor outlets.
(Bi-level): This setting directs air through the
floor outlets as well as the instrument panel outlets.
(Floor): This setting directs most of the airflow
through the floor outlets and some air through the
windshield defroster outlets. Recirculation will not be
available in this mode. See ªRecirculationº following
for more information.
(Blend): This setting divides airflow equally
between the floor outlets and the windshield defroster
outlets. The air conditioning compressor may run to
dehumidify the air to prevent window fogging.
Recirculation will not be available in this mode. See
ªRecirculationº following for more information.
(Defrost): This setting directs most air through the
windshield defroster outlets and some through the floor
outlets. The air conditioning compressor may run to
dehumidify the air to prevent window fogging.
Recirculation will not be available in this mode. See
ªRecirculationº following for more information.
Mode Buttons
(Outside air): Press this button, located
under the fan knob, to use outside air. Using outside
air will limit stale air odors and help to prevent
excessively humid interior air (from wet boots or
clothing or maximum passenger loads) from being
redirected onto windows.
Pressing the outside air button will cancel the
recirculation button.