2002 CHEVROLET TRAIL BLAZER Owners Manual

3-5
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.
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 pressed again or the AUTO button is pressed.
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.

3-6
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.
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), thesystem 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. Pressing the fan switch will override this
delay and change the fan to a selected speed.

3-7
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.
(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 vehicleIf 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.

3-8 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.
If your vehicle has the automatic system, press the
AUTO button and the system will cool and dehumidify
the air inside the vehicle. Also while in this 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 the FRONT defrost button
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.

3-9
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.
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, press 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.

3-10 Rear Comfort Controls
Your vehicle has one of the following rear comfort
control systems. With either system, the rear comfort
controls will be disabled when the front comfort control
system is in defrost. This occurs to provide maximum
airflow to clear the windshield.
The temperature of the air coming through the rear
outlets is determined by the front passenger's
temperature setting. Press the PWR button to turn the
rear comfort controls on and off. Use the mode knob to
change the direction of airflow (upper, bi
-level or floor)
to the rear seat area.
If your vehicle has the rear seat audio system the lower
buttons are used to adjust the rear seat comfort controls.
The temperature of the air coming through the rear
outlets is determined by the front passenger's
temperature setting. The button with the up and down
arrows on it regulates the fan speed. The mode button
can be used to change the direction of airflow (upper,
bi
-level or floor) to the rear seat area. To turn the rear
comfort controls off, press the lower PWR button.

3-11 Ventilation System
For mild outside temperatures when little heating
or cooling is needed, use the panel outlet setting
(on the manual system) to direct outside air through
your vehicle. Air will flow through the instrument
panel outlets.
Your vehicle's flow
-through ventilation system supplies
outside air into the vehicle when it's moving. When the
vehicle is not moving, you can get outside air to flow
through by selecting any air delivery mode and any
fan speed.
Your vehicle has air outlets that allow you to adjust
the direction and amount of airflow inside the vehicle.
Move the louvers up or down and move the control
in the center of each outlet side
-to-side to direct the
air from the outlet. Use the thumbwheel next to or
underneath the outlet to close the louvers. For the most
efficient airflow and temperature control, keep the outlet
in the fully opened position.
The rear seat outlets can be used to adjust the airflow
toward either seating area, the floor or upward. Move
the control in the center of each outlet in any direction
to direct airflow.

3-12
Ventilation Tips

Keep the hood and front air inlet free of ice, snow or
any other obstruction such as leaves. The heater and
defroster will work better, reducing the chance of
fogging your windows.

In cool damp weather, minimize your use of
recirculation to reduce the chance of fogging
your windows.

When you enter a vehicle with the manual system in
cold weather, select floor mode to supply air through
the floor outlets. Then turn the fan on high for a few
moments before driving away. This will blow moist
air from the intake outlets toward the floor, not the
windshield. It reduces the chance of fogging your
windows. If you have the automatic system, the
AUTO setting will do this for you. Manual operation
of the automatic system in the floor mode will also
supply air through the floor outlets.

Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.Comfort Control Steering Wheel Controls
(If Equipped)
If your vehicle has this
feature, you can control
certain comfort control
functions using the buttons
on your steering wheel.
(Fan): Press the up arrow to increase the fan speed
and the down arrow to decrease the fan speed.
(Temperature): Press the up arrow to increase the
temperature of the air flowing through the system and
the down arrow to decrease the temperature of the air
flowing through the system.