2002 GMC ENVOY air condition

1-27
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.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 the driver's and
right front passenger's side impact air bags.

2-78
Charging System Indicator Light
The charging system
light will come on briefly
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.
Voltmeter Gage
When your engine is not
running, but the ignition is
on (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.

2-83
NOTICE:
Modifications made to the engine, transmission,
exhaust, intake or fuel system of your vehicle or
the replacement of the original tires with other
than those of the same Tire Performance Criteria
(TPC) can affect your vehicle's emission controls
and may cause the SERVICE ENGINE SOON or
CHECK ENGINE light to come on.
Modifications to these systems could lead to
costly repairs not covered by your warranty. This
may also result in a failure to pass a required
Emission Inspection/Maintenance test.
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.

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
-7 Air Conditioning
3
-8 Heating
3
-8 Defogging and Defrosting
3
-9 Rear Window Defogger
3
-11 Ventilation System
3
-13 Audio Systems
3
-13 Setting the Clock
3
-13 AM-FM Stereo with Compact Disc Player
with Radio Data System (RDS) and Automatic
Tone Control
3
-22 AM-FM Stereo with Cassette Tape and
Compact Disc Player with Radio Data
System (RDS) and Automatic Tone Control
(If Equipped)3
-33 AM-FM Stereo with 6-Disc Compact Disc
Player with Programmable Equalization and
Radio Data System (RDS) (If Equipped)
3
-45 Rear Seat Entertainment System (RSE)
(If Equipped)
3
-57 Rear Seat Audio (If Equipped)
3
-58 Theft-Deterrent Feature RDS Radios
3
-59 Audio Steering Wheel Controls (If Equipped)
3
-59 Understanding Radio Reception
3
-60 Tips About Your Audio System
3
-61 Care of Your Cassette Tape Player
3
-62 Care of Your Compact Disc and DVD Player
3
-62 Care of Your Compact Discs and DVDs
3
-62 Cleaning the Video Screen
3
-63 Diversity Antenna System
3
-63 Chime Level Adjustment

3-3
Passenger's Side Temperature Lever
The lever on the right side of the climate control panel
is used to adjust the air temperature on the passenger's
side, independent of the temperature set by the driver.
Slide the lever upward to raise the temperature. Slide
the lever downward to lower the temperature.
This lever also adjusts the temperature to the rear
seat outlets.
Mode Knob
The knob on the right side of the control panel has
several settings to control the direction of airflow:
(Panel): Selecting panel mode will deliver air to
the instrument panel outlets.
(Bi-Level): Selecting bi-level mode will deliver
warmer air to the floor and cooler air to the instrument
panel outlets.
(Floor): Selecting floor mode will deliver air to
the floor outlets and some air to the defroster and side
window vents.
(Defog): Selecting defog will deliver air to the
floor, windshield outlets and side window vents.
(Defrost): Selecting this setting directs most of the
air through the defroster and side window vents. Some
of the air also goes to the floor ducts.
Mode Buttons
(Recirculation): Press this button to limit the
amount of outside air entering your vehicle. This is
helpful when you are trying to limit odors entering your
vehicle and for maximum air conditioning performance
in hot weather. Recirculation cannot be used in floor,
blend or defrost modes. An indicator on the button will
light up, flash three times and turn off when
recirculation is selected in these modes.
While in the recirculation mode the windows may fog
when the weather is cold and damp. To clear the fog,
select either the blend or defrost mode and increase the
fan speed.
(Air Conditioning): Press this button to turn the
air conditioning compressor on and off. The system will
cool and dehumidify the air inside the vehicle when the
air conditioning compressor is engaged.

3-5
Fan Switch
The switch with the fan symbol allows you to manually
adjust the fan speed. Press the up arrow to increase fan
speed and the down arrow to decrease fan speed.
MODE Button
Press this button to manually select the air delivery
mode to the floor, panel or windshield outlets. The
system will stay in the selected mode until the MODE
button is pushed again or the AUTO button is pushed.
Display
In full AUTO mode, the automatic climate control
system display will show the outside temperature,
labeled EXT for external temperature, and AUTO. If
you press the MODE button to select an air delivery
mode, the display will change to also show you the
current system mode. If you press the up or down
arrows on the fan switch, the display will change to
show the selected fan speed. After five seconds, the
display will change to show the EXT temperature and
the selected manual setting.Automatic Operation
Press the AUTO button to set the system to
automatically control the air delivery mode, fan speed,
air temperature and recirculation operations. Whenever
you press AUTO, the display will change to show the
current driver's set temperature, automatic air delivery
mode and fan speed. Press the AUTO button again
within five seconds and the display will show the
passenger's set temperature. After five seconds the
display will change to the EXT (external) temperature
outside the vehicle.
When AUTO is selected, the air conditioning operation
and air inlet will be automatically controlled. The air
conditioning compressor will run when outside
temperature is over approximately 40
F (4
C).
The air inlet will normally be set to outside air. If it's
hot outside, the air inlet will automatically switch to
recirculated inside air to help quickly cool down
your vehicle.

3-7
(Recirculation): Press this button to limit the
amount of outside air entering your vehicle. This is
helpful when you are trying to limit odors entering your
vehicle and for maximum air conditioning performance
in hot weather. Press this button again to allow outside
air to enter the vehicle.
If you select recirculation while in defrost, defog or
floor, the light on the button will flash and go out to let
you know this is not allowed. This is to prevent fogging.
When the weather is cool or damp, operating the system
in recirculation for extended periods of time may cause
fogging of the vehicle's windows. To clear the fog,
select either defog or FRONT defrost. Be sure A/C OFF
is not selected to allow the air conditioning compressor
to run automatically and help dehumidify the air.
(Air Conditioning): Press this button to turn the
air conditioning compressor on and off. When air
conditioning is selected or in AUTO mode, the system
will run the air conditioning automatically to cool and
dehumidify the air entering the vehicle. If you select
A/C OFF while in FRONT defrost, the A/C OFF text
will flash to let you know this is not allowed. This is to
prevent fogging.
FRONT (Defrost): Press this button to defrost the
windshield. The system will automatically control the
fan speed if you select defrost from AUTO. If the
outside temperature is 40
F (4
C) or warmer, your air
conditioning compressor will automatically run to help
dehumidify the air and dry the windshield.
Air Conditioning
On hot days, open the windows long enough to let hot
inside air escape. This reduces the time it takes for your
vehicle to cool down. Then keep your windows closed
for the air conditioner to work its best.
If your vehicle has the manual system, for quick
cool
-down on very hot days, use the airflow from the
panel outlets, press recirculation and air conditioning
with the temperature control in the blue area. If this max
air conditioning setting is used for long periods of time,
the air in your vehicle may become too cold and dry.
For normal cooling on hot days, use air conditioning
without recirculation with the temperature control in the
blue area.

3-8
If your vehicle has the automatic system, in AUTO
mode the system will cool and dehumidify the air
inside the vehicle. Also while in AUTO mode, the
system will maximize its performance by using
recirculation as necessary.
On cool, but sunny days, with the manual system or
through manual operation of the automatic system,
use bi
-level to deliver warm air to the floor and cooler
air to the instrument panel outlets. To warm or cool
the air delivered, turn the temperature control to the
desired setting.
Heating
If you have the manual system, on cold days use floor
with the temperature lever in the red area. If you have
the automatic system, press AUTO and adjust the
temperature by turning the temperature knob clockwise
or counterclockwise. You may also adjust the automatic
system manually by pressing the MODE button and
selecting floor. Again, adjust the temperature by turning
the temperature knob clockwise or counterclockwise.
With either system, outside air will be heated and sent
through the floor outlets. The heater works best if you
keep the windows closed while using it.
Defogging and Defrosting
On cool, humid days, use defog to keep the windshield
and side windows clear. Use front defrost to remove fog
or ice from the windshield quickly in extremely humid
or cold conditions.
If your vehicle has the manual system, select defog and
adjust the fan speed to your comfort level. Turn the air
conditioning on to help dehumidify the air. Use front
defrost with the temperature toward the red area and the
fan control toward high.
If your vehicle has the automatic system and you select
FRONT defrost or defog from AUTO, the system will
control the fan speed. Adjust the temperature and fan
speed to your comfort level. After the windshield is
clear, adjust the temperature to your normal setting and
select the AUTO button and return to AUTO mode and
fan control.
For maximum front defrost performance under extreme
icing or frosting conditions, increase the temperature
setting to 90
F (32
C) and increase the fan speed
to high.