2008 CHEVROLET SILVERADO air conditioning

Driver and Passenger Side Temperature
Controls
The driver and passenger side temperature buttons
are used to adjust the temperature of the air coming
through the system on the driver or passenger’s side of
the vehicle. The temperature can be adjusted even if
the system is turned off. This is possible since outside
air always ows through the system as the vehicle
is moving forward unless it is set to recirculation mode.
See “Recirculation” later in this section.
Press the + or−buttons to increase or decrease the
cabin temperature. The driver side or passenger
side temperature display shows the temperature setting
decreasing or increasing.
The passenger’s temperature setting can be set to
match the driver’s temperature setting by pressing the
PASS button and turning off the PASS indicator.
When the passenger’s temperature setting is set
different than the driver’s setting, the indicator on the
PASS button illuminates and both the driver’s side and
passenger’s side temperature displays are shown.
Automatic Operation
AUTO (Automatic):When automatic operation is
active the system controls the inside temperature,
the air delivery, and the fan speed.
Use the steps below to place the entire system in
automatic mode:
1. Press the AUTO button.
When AUTO is selected, the display changes to
show the current temperature(s) and AUTO is lit on
the display. The current air delivery mode and
fan speed are also displayed for about 5 seconds.
When AUTO is selected, the air conditioning
operation and air inlet are automatically controlled.
The air conditioning compressor may run when
the outside temperature is above freezing. The air
inlet will normally be set to outside air. If it is hot
outside, the air inlet may automatically switch to the
recirculate mode to help quickly cool down the
air inside the vehicle. The light on the button comes
on in recirculation.
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2. Set the driver’s and passenger’s temperature.
To nd your comfort setting, start with a 74°F (23°C)
temperature setting and allow about 20 minutes
for the system to regulate. Use the driver’s or
passenger’s temperature buttons to adjust the
temperature setting as necessary. If you choose the
temperature setting of 60°F (15°C), the system
remains at the maximum cooling setting. If you
choose the temperature setting of 90°F (32°C),
the system remains at the maximum heat setting.
Choosing either maximum setting will not cause the
vehicle to heat or cool any faster.
Be careful not to cover the solar sensor located on
the top of the instrument panel near the windshield.
This sensor regulates air temperature based on
sun load. For more information on the solar sensor,
see “Sensors” later in this section.
To avoid blowing cold air in cold weather, the system
delays turning the fan on until warm air is available.
The length of delay depends on the engine coolant
temperature. Pressing the fan switch overrides this delay
and changes the fan to a selected speed.O(On/Off):Press this button to turn off the climate
control system. Outside air still enters the vehicle, and
is directed to the oor. This direction can be changed by
pressing the mode button. Recirculation can be
selected once you have selected vent or bi-level mode.
The temperature can also be adjusted using either
temperature button. If the air delivery mode or
temperature settings are adjusted with the system off,
the display illuminates briey to show the settings
and then returns to off. Press the on/off button or the up
down arrows on the fan switch, the defrost button,
AUTO button, or the air conditioning button to turn the
system on when it is off.
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The recirculation mode cannot be used with oor, defog,
or defrost modes. If recirculation is selected with one of
those modes, the indicator light ashes three times and
then turns off. The air conditioning compressor also
comes on when this mode is activated. While in
recirculation mode the windows may fog when the
weather is cold and damp. To clear the fog, select either
the defog or defrost mode and increase the fan speed.
The recirculation mode can be turned off by pressing the
outside air button, or by turning off the ignition.
;(Outside Air):Press this button to turn on the
outside air mode. When this mode is selected, air from
outside the vehicle circulates throughout the vehicle.
An indicator light on the button comes on to show
that it is activated. The outside air mode can be
used with all modes, but it cannot be used with the
recirculation mode.
Air Conditioning
#
(Air Conditioning):Press this button to turn the air
conditioning (A/C) compressor on and off. When air
conditioning is selected, an indicator light comes on to
show that the air conditioning has been activated.
Pressing this button when the outside temperature is
too cool for air conditioning makes the air conditioning
indicator ash three times and then turn off to let
you know the air conditioning mode is not available.
If the air conditioning is on and the outside temperature
drops below a temperature which is too cool for air
conditioning to be effective, the air conditioning light
turns off to show that the air conditioning mode has
been canceled.
On hot days, open the windows long enough to let hot
inside air escape. This helps to reduce the time it
takes for the vehicle to cool down. It also helps the
system to operate more efficiently.
The air conditioning system removes moisture from the
air, so a small amount of water might drip underneath
the vehicle while idling or after turning off the engine.
This is normal.
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Sensors
The solar sensor, located
in the defrost grille, in the
middle of the instrument
panel, monitors the
solar radiation. Do not
cover the solar sensor or
the system will not
work properly.
The interior temperature
sensor, located in the
headliner, measures 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 on the rearview mirror.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 the windshield.
Use
HandGto select the defog or defrost modes.
-(Defog):Press this button 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.
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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 your
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.
Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog from the rear window.
<(Rear Window Defogger):If your vehicle has this
feature, press this button to turn the defogger on or
off. It automatically turns off several minutes after it has
been activated. The defogger can also be turned off
by turning the engine off. Do not drive the vehicle until
all the windows are clear.
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.Heated Mirrors: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. SeeOutside Power
Mirrors on page 2-61.
Outlet Adjustment
Use the air outlets located in the center and on the side
of the instrument panel to direct the airow. Use the
thumbwheels near the air outlets to open or close off
the airow.
Operation Tips

Clear away any ice, snow, or leaves from air inlets
at the base of the windshield that could block the
ow of air into the vehicle.
Keep the path under the front seats clear of objects
to help circulate the air inside of the vehicle more
effectively.
Use of non-GM approved hood deectors can
adversely affect the performance of the system.
Check with your dealer/retailer before adding
equipment to the outside of your vehicle.
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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 3-48.
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 5-32
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 3-48.
SeeOverheated Engine Protection Operating Mode
(V8 Engines Only) on page 5-34for information
on driving to a safe place in an emergency.
ENGINE OVERHEATED STOP 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 5-32
for more information.
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Driving with a Trailer
{CAUTION:
If you have a rear-most window open and you
pull a trailer with your vehicle, carbon monoxide
(CO) could come into your vehicle. You cannot
see or smell CO. It can cause unconsciousness
or death. SeeEngine Exhaust on page 2-54.To
maximize your safety when towing a trailer:
Have your exhaust system inspected for
leaks, and make necessary repairs before
starting on your trip.
Keep the rear-most windows closed.
CAUTION: (Continued)
CAUTION: (Continued)

If exhaust does come into your vehicle
through a window in the rear or another
opening, drive with your front, main
heating or cooling system on and with the
fan on any speed. This will bring fresh,
outside air into your vehicle. Do not use
the climate control setting for maximum air
because it only recirculates the air inside
your vehicle. SeeClimate Control System
(With Air Conditioning ) on page 3-25or
Climate Control System (Heater Only) on
page 3-28.
Towing a trailer requires a certain amount of experience.
Before setting out for the open road, you’ll want to get
to know your rig. Acquaint yourself with the feel of
handling and braking with the added weight of the trailer.
And always keep in mind that the vehicle you are
driving is now a good deal longer and not nearly as
responsive as your vehicle is by itself.
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Engine Fan Noise
If your vehicle has a clutched engine cooling fan, when
the clutch is engaged, the fan spins faster to provide
more air to cool the engine. In most everyday driving
conditions, the fan is spinning slower and the clutch is
not fully engaged. This improves fuel economy and
reduces fan noise. Under heavy vehicle loading, trailer
towing, and/or high outside temperatures, the fan
speed increases as the clutch more fully engages, so
you may hear an increase in fan noise. This is normal
and should not be mistaken as the transmission slipping
or making extra shifts. It is merely the cooling system
functioning properly. The fan will slow down when
additional cooling is not required and the clutch
disengages.You may also hear this fan noise when you start the
engine. It will go away as the fan clutch partially
disengages.
If your vehicle has electric cooling fans, you may hear
the fans spinning at low speed during most everyday
driving. The fans may turn off if no cooling is required.
Under heavy vehicle loading, trailer towing, and/or
high outside temperatures, or if you are operating your
air conditioning system, the fans may change to
high speed and you may hear an increase in fan noise.
This is normal and indicates that the cooling system
is functioning properly. The fans will change to low
speed when additional cooling is no longer required.
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