2008 CHEVROLET SUBURBAN air condition

The interior temperature sensors located in the headliner
above the driver side seat and if equipped, in the
headliner above the second row seats measure the
temperature of the air inside the vehicle.
There is also an exterior temperature sensor located
behind the front grille. This sensor reads the outside air
temperature and helps maintain the temperature
inside the vehicle. Any cover on the front of the vehicle
could cause a false reading in the displayed
temperature.
The climate control system uses the information from
these sensors to maintain your comfort setting by
adjusting the outlet temperature, fan speed, and the air
delivery mode. The system may also supply cooler
air to the side of the vehicle facing the sun. The
recirculation mode will also be used as needed to
maintain cool outlet temperatures.
Defogging and Defrosting
Fog on the inside of the windows is a result of high
humidity (moisture) condensing on the cool window
glass. This can be minimized if the climate control
system is used properly. There are two modes to clear
fog or frost from your windshield.
Use the mode up and down arrows to select the defog
or defrost modes.
-(Defog):The defog mode is used to clear the
windows of fog or moisture and warm the passengers.
This mode directs air to the windshield, oor outlets,
and side window vents. When this mode is selected,
the system turns off recirculation and runs the air
conditioning compressor unless the outside temperature
is close to freezing. The recirculation mode cannot be
selected while in the defog mode. Do not drive the
vehicle until all the windows are clear.
0(Defrost):Press this button to remove fog or frost
from the windshield more quickly. This mode directs
a portion of the air to the windshield and side window
vents and some to the oor vents. In this mode, the
system will automatically force outside air into the
vehicle. The recirculation mode cannot be selected while
in the defrost mode. The air conditioning compressor
will run automatically in this setting, unless the outside
temperature is close to freezing. Do not drive the
vehicle until all the windows are clear.
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Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog from the rear window.
<(Rear Window Defogger):Press this button to
turn on the rear window defogger. It will automatically
turn off several minutes after it has been activated.
The defogger can also be turned off by pressing
the button again or by turning off the engine. Do not
drive the vehicle until all the windows are clear.
If your vehicle has heated outside rearview mirrors, the
mirrors will heat to help clear fog or frost from the
surface of the mirror when the rear window defog button
is pressed.
Notice:Do not use a razor blade or sharp object to
clear the inside rear window. Do not adhere
anything to the defogger grid lines in the rear glass.
These actions may damage the rear defogger.
Repairs would not be covered by your warranty.
Outlet Adjustment
Use the air outlets located in the center and on the side
of your instrument panel to direct the airow.
Operation Tips

Keep the hood and front air inlets free of ice, snow,
or any other obstruction (such as leaves). The
heater and defroster will work far better, reducing
the chance of fogging the inside of your windows.
When you enter a vehicle in cold weather, press the
fan up button to the maximum fan level before
driving. This helps clear the intake ducts of snow
and moisture, and reduces the chance of fogging
the inside of your window.
Keep the air path under the front seats clear of
objects. This helps air to circulate throughout
your vehicle.
Adding outside equipment to the front of your
vehicle, such as hood-air deectors, may affect the
performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
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Rear Air Conditioning and Heating
System
If your vehicle has this system, the rear controls are
three knobs located in the headliner. The system can
be controlled from the front controls as well as the rear
controls.
To turn the system on, press the AUX button on the
front climate control system, an indicator will be
lit. Pressing the AUX button the rst time will turn the
rear system on in a mimic mode. In this mode, the
airow in the rear will be approximately the same
direction, temperature, and fan speed as the front.
Pressing the AUX button again will turn the rear system
and the indicator off.
If the rear controls are adjusted, the system will enter a
rear independent mode. Airow in the rear will then
be directed according to the settings of rear controls.
The rear system can be turned off by pressing the
AUX button on the front climate control system and the
indicator will turn off.
Fan Knob
Turn the left knob clockwise or counterclockwise to
increase or decrease the fan speed. Turn the knob all
the way counterclockwise to turn the rear system off.
Temperature Knob
The middle knob on the control panel lets you select
the temperature of the air owing into the passenger
area. Turn the knob clockwise toward the red area for
warmer air. Turn the knob counterclockwise toward
the blue area for cooler air.
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Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
H(Vent):This setting directs the air through the
headliner outlets.
)(Bi-Level):Air is delivered through the oor outlets
as well as the headliner outlets. The rear system
oor outlets are located directly behind the second row
seats. The ow can be divided between vent and
oor outlets depending upon where the knob is placed
between the settings.
6(Floor):This setting directs most of the air through
the oor outlets. The rear system oor outlets are
located directly behind the second row seats.
Rear Air Conditioning and Heating
System and Electronic Climate
Controls
For vehicles with the rear heat and air conditioning
controls, they are integrated with the rear seat audio
controls located in the center console. The system can
be controlled from the front controls as well as the
rear controls.
To turn the system on, press the AUX button on the
front climate control system, an indicator will be
lit. Pressing the AUX button the rst time will turn the
rear system on in a mimic mode. In this mode, the
airow in the rear will be approximately the same
direction, temperature, and fan speed as the front.
Pressing the AUX button again turns the rear system
and the indicator off.
If the rear controls are adjusted, the system enters a
rear independent mode. Airow in the rear will then
be directed according to the settings of rear controls.
The rear system can be turned off by pressing the
AUX button on the front climate control system and the
indicator will turn off.
If the indicator in the front AUX button is off, the rear
system is off.
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Charging System Light
This light will come on
briey when you turn on
the ignition key, 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 driving, there could be a problem
with the charging system. A charging system Driver
Information Center (DIC) message may also appear.
SeeDIC Warnings and Messages on page 3-59
for more information. This light could indicate that there
are problems with a generator drive belt, or that
there is an electrical problem. Have it checked right
away. If you must drive a short distance with the light on,
be certain to turn off all the accessories, such as the
radio and air conditioner.
Voltmeter Gage
When your engine is not
running, but the ignition is
on, this gage shows
the battery’s state of
charge in DC volts.
When the engine is running, the gage shows the
condition of the charging system. The charging system
regulates voltage based on the state of the battery
for improved fuel economy and battery life. The gage
may transition from a higher to lower or a lower to higher
reading, this is normal. Readings between the low
and high warning zones indicate the normal operating
range. The gage may also read low during the fuel
economy mode, this is normal.
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Notice:Modications 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 can cause this light to come on.
Modications to these systems could lead to costly
repairs not covered by your warranty. This could
also result in a failure to pass a required Emission
Inspection/Maintenance test. SeeAccessories
and Modifications on page 5-3.
This light comes on, as a check to show it is working,
when the ignition is turned ON/RUN but the engine is not
running. If the light does not come on, have it repaired.
This light also comes on during a malfunction in
one of two ways:
Light Flashing— A misre condition has been
detected. A misre increases vehicle emissions and
could damage the emission control system on your
vehicle. Diagnosis and service might be required.
Light On Steady— An emission control system
malfunction has been detected on your vehicle.
Diagnosis and service might be required.
If the Light is Flashing
The following can prevent more serious damage to
your vehicle:
Reduce vehicle speed.
Avoid hard accelerations.
Avoid 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 ashing and remains on steady,
see “If the Light Is On Steady” following.
If the light continues to ash, when it is safe to do so,
stop the vehicle. Find a safe place to park the vehicle.
Turn the ignition off, wait at least 10 seconds, and restart
the engine. If the light remains on steady, see “If the
Light Is On Steady” following. If the light is still ashing,
follow the previous steps and see your dealer/retailer
for service as soon as possible.
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CHECK TIRE PRESSURE
This message displays when the pressure in one or
more of the vehicle’s tires needs to be checked.
This message also displays LEFT FRONT, RIGHT
FRONT, LEFT REAR, or RIGHT REAR to indicate which
tire needs to be checked. You can receive more than
one tire pressure message at a time. To read the other
messages that may have been sent at the same
time, press the set/reset button or the trip odometer
reset stem. If a tire pressure message appears on the
DIC, stop as soon as you can. Have the tire pressures
checked and set to those shown on the Tire Loading
Information label. SeeTires on page 5-66,Loading the
Vehicle on page 4-35, andInflation - Tire Pressure
on page 5-74. The DIC also shows the tire pressure
values. See “DIC Operation and Displays (With
DIC Buttons)” earlier in this section. If the tire pressure
is low, the low tire pressure warning light comes on.
SeeTire Pressure Light on page 3-44.
DRIVER DOOR OPEN
This message displays and a chime sounds if the driver
door is not fully closed and the vehicle is in a drive
gear. Stop and turn off the vehicle, check the door for
obstructions, and close the door again. Check to
see if the message still appears on the DIC.
ENGINE HOT A/C (Air Conditioning)
TURNED OFF
This message displays when the engine coolant
becomes hotter than the normal operating temperature.
SeeEngine Coolant Temperature Gage on page 3-43.
To avoid added strain on a hot engine, the air
conditioning compressor automatically turns off. When
the coolant temperature returns to normal, the air
conditioning compressor turns back on. You can
continue to drive your vehicle.
If this message continues to appear, have the system
repaired by your dealer/retailer as soon as possible
to avoid damage to the engine.
ENGINE OVERHEATED IDLE ENGINE
Notice:If you drive your vehicle while the engine
is overheating, severe engine damage may occur.
If an overheat warning appears on the instrument
panel cluster and/or DIC, stop the vehicle as soon
as possible. SeeEngine Overheating on page 5-34
for more information.
This message displays when the engine coolant
temperature is too hot. Stop and allow the vehicle to
idle until it cools down. SeeEngine Coolant
Temperature Gage on page 3-43.
SeeOverheated Engine Protection Operating Mode on
page 5-36for information on driving to a safe place
in an emergency.
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REPLACE BATTERY IN REMOTE KEY
This message displays if a Remote Keyless Entry (RKE)
transmitter battery is low. The battery needs to be
replaced in the transmitter. See “Battery Replacement”
underRemote Keyless Entry (RKE) System Operation
on page 2-5.
RIGHT REAR DOOR OPEN
This message displays and a chime sounds if the
passenger side rear door is not fully closed and the
vehicle is in a drive gear. Stop and turn off the vehicle,
check the door for obstructions, and close the door again.
Check to see if the message still appears on the DIC.
SERVICE 4 WHEEL DRIVE
This message displays if a problem occurs with the
four-wheel-drive system. If this message appears, stop
as soon as possible and turn off the vehicle. Restart
the vehicle and check for the message on the DIC
display. If the message is still displayed or appears
again when you begin driving, the four-wheel-drive
system needs service. See your dealer/retailer.
SERVICE AIR BAG
This message displays if there is a problem with
the airbag system. Have your dealer/retailer inspect
the system for problems. SeeAirbag Readiness Light
on page 3-37andAirbag System on page 1-76for
more information.
SERVICE BATTERY CHARGING
SYSTEM
On some vehicles, this message displays if there is a
problem with the battery charging system. Under certain
conditions, the charging system light may also turn
on in the instrument panel cluster. SeeCharging System
Light on page 3-40. Driving with this problem could
drain the battery. Turn off all unnecessary accessories.
Have the electrical system checked as soon as
possible. See your dealer/retailer.
SERVICE BRAKE SYSTEM
This message displays along with the brake system
warning light if there is a problem with the brake system.
SeeBrake System Warning Light on page 3-41. If this
message appears, stop as soon as possible and turn
off the vehicle. Restart the vehicle and check for
the message on the DIC display. If the message is still
displayed or appears again when you begin driving,
the brake system needs service as soon as possible.
See your dealer/retailer.
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