2002 GMC ENVOY Owner's Manual

3-2
Comfort Controls
This section tells you how to use the comfort controls.
With these systems, you can control the heating,
cooling and ventilation in your vehicle. Your vehicle
also has a flow
-through ventilation system described
later in this section.
Comfort Controls Personalization
(If Equipped)
If your vehicle is equipped with the automatic comfort
control system and memory seats and mirrors, you
can store and recall the climate control settings for
temperature, air delivery mode and fan speed for
two different drivers. The personal choice settings
recalled are determined by the transmitter used to enter
the vehicle. After the button with the unlock symbol on
a remote keyless entry transmitter is pressed, the climate
control will adjust to the last settings of the identified
driver. The settings can also be changed by pressing
one of the memory buttons (1 or 2) located on the
driver's door. When adjustments are made, the new
settings are automatically saved for that driver.
Manual Dual Zone Comfort Controls
With this system, you can select different comfort
control settings for the driver and passengers.
Fan Knob
The knob on the left side of the climate control panel
regulates the fan speed. You can choose from
five different fan speeds or turn the fan off.
Driver's Side Temperature Lever
The lever on the left side of the climate control panel is
used to adjust the air temperature on the driver's side,
independent of the temperature set by the passenger.
Slide the lever upward to raise the temperature. Slide the
lever downward to lower the temperature.

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.

3-4 Automatic Dual Zone Comfort Control
System (Option)
With this system, you can select different comfort
control settings for the driver and passengers.
Driver's Side Temperature Knob
The driver's side knob is used to adjust the temperature
of the air coming through the system on the driver's
side. Turn the knob counterclockwise to lower the cabin
temperature. The display will show the temperature
decreasing as you turn the knob counterclockwise. Turn
the knob clockwise to increase the cabin temperature.The display will show the temperature increasing as you
turn the knob clockwise. When this knob is adjusted, the
word DRIVER will be displayed under the temperature
setting. If the passenger's set temperature has not been
adjusted, this knob controls both the driver's and
passenger's air temperature.
Passenger's Side Temperature Knob
The passenger's side knob can be used to change the
temperature of the air coming through the system on
the passenger's side of the vehicle. Turn the knob
counterclockwise to lower the cabin temperature. The
display will show the temperature decreasing as you turn
the knob counterclockwise. Turn the knob clockwise to
increase the cabin temperature. The display will show
the temperature increasing as you turn the knob
clockwise. When this knob is adjusted, only the word
PASS will be displayed under the temperature setting.
The temperature to the rear seat area is controlled by
using this knob.
Once this knob is used, the passenger's set temperature
will remain independent of the driver's until the ignition
has been turned off.

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.

3-6
To find your comfort setting, start with a 74
F (23
C)
temperature setting and allow about 20 minutes for the
system to regulate. Turn the driver's or passenger's side
temperature knob clockwise or counterclockwise to
adjust the temperature setting as necessary. If you
choose the temperature setting of 60
F (15
C), the
system will remain at the maximum cooling setting
and fan speed. If you choose the temperature setting of
90
F (32
C), the system will remain at the maximum
heat setting and fan speed. Choosing either maximum
setting will not cause the system to heat or cool any
faster.
Be careful not to cover the sensor located on the top of
the instrument panel near the windshield. This sensor
regulates air temperature based on sun load, and also
turns on your headlamps.
The EXT (exterior) temperature sensor is located in the
front of the vehicle behind the grille. The displayed
temperature is most accurate after the vehicle has been
moving for a few minutes. If the vehicle is stopped and
then restarted within 2 1/2 hours, the sensor will be hot
from the engine heat. In this case, the temperature first
displayed will continue to be the temperature that was
displayed before the vehicle was turned off. The display
will update after the vehicle has been moving for a few
minutes and the sensor has a chance to cool down to the
actual temperature.To avoid blowing cold air in cold weather, the system
will delay turning on the fan until warm air is available.
The length of delay depends on the engine coolant
temperature. Pushing the fan switch will override this
delay and change the fan to a selected speed.
Manual Operation
You may manually adjust the air delivery mode or fan
speed. Use the mode button to cycle through the
following four air delivery modes:
(Panel): This setting will deliver air to the
instrument panel outlets.
(Bi-Level): This setting will deliver warmer air to
the floor and cooler air to the instrument panel outlets.
(Floor): This setting will deliver air to the
floor outlets.
(Defog): This setting will deliver air to the floor
and windshield outlets.
OFF: Press this button to turn the system off. Some
fresh air will continue to flow through the vehicle from
the floor outlets. The system will try to maintain the
previously chosen temperature setting.

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.

3-9 Rear Window Defogger
The lines you see on the rear window warm the glass.
Press the button to start warming your window. A light
will glow in the button while the defogger is working.
If your vehicle is equipped with heated mirrors, this
button will activate them.
After 10 minutes it will turn off by itself, or press the
button during the heating cycle to turn it off. If you need
additional warming time, push the button again.Do not attach a temporary vehicle license, tape or decals
across the defogger grid on the rear window.
NOTICE:
Do not try to clear frost or other material from
the inside of the rear window with a razor blade
or anything else that is sharp. This may damage
the defogger grid. The repairs wouldn't be
covered by your warranty.