2009 GMC SIERRA air conditioning

Dual Automatic Climate Control
System
The heating, cooling, and ventilation in the vehicle can be
controlled with this system. The vehicle also has a
ow-through ventilation system described later in
this section.
A. Driver and Passenger
Temperature Controls
B. Fan Control
C. AUTO
D. Defrost
E. Recirculation
F. Outside AirG. Air Delivery Mode
Control
H. Display
I. Power Button
J. Rear Window
Defogger
K. Air Conditioning
L. PASS (Passenger)
O(On/Off):Press to turn the climate control system
on or off. 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. The system can be turned back
on by pressing either
O,D,C,#, the defrost or
the AUTO button.
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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 side
and passenger 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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6(Floor):Air is directed to the oor outlets, with
some to the windshield, side window outlets, and
second row oor outlets. In this mode, the system
automatically selects outside air.
-(Defog):This mode clears the windows of fog or
moisture. Air is directed to the windshield, oor outlets,
and side window vents. In this mode, 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 defrost mode.
0(Defrost):This mode removes fog or frost from
the windshield more quickly. Air is directed to the
windshield and side window vents, with some directed
to the oor vents. In this mode, the system automatically
forces outside air into the vehicle and runs the air
conditioning compressor unless the outside temperature
is close to freezing. The recirculation mode cannot be
selected while in the defrost mode.
Do not drive the vehicle until all the windows are clear.
#(Air Conditioning):Press to turn the air conditioning
(A/C) compressor on and off. An indicator light comes
on to show that the air conditioning is on.
If this button is pressed when the air conditioning
compressor is unavailable due to outside conditions,
the indicator ashes three times and then turns off.
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 under the
vehicle while idling or after turning off the engine.
This is normal.
@(Recirculation):Press to turn the recirculation
mode on. An indicator light comes on to show that the
recirculation is on.
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This mode recirculates and helps to quickly cool the
air inside the vehicle. It can be used to help prevent
outside air and odors from entering the vehicle.
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 to turn the outside air mode
on. An indicator light on the button comes on to show
that outside is on. When selected, air from outside
the vehicle circulates throughout the vehicle. The outside
air mode can be used with all modes, but it cannot be
used with the recirculation mode.
Rear Window Defogger
The rear window defogger uses a warming grid to
remove fog from the rear window.
<(Rear Window Defogger):For vehicles with
this feature, press 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:For vehicles with heated outside
rearview mirrors, the mirrors 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 2-59.
3-31

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 3-44.
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 OIL HOT IDLE ENGINE
This message displays when the engine oil becomes
hotter than the normal operating temperature. Stop and
allow the vehicle to idle until it cools down. SeeEngine
Coolant Temperature Gage on page 3-44.
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 3-44.
SeeOverheated Engine Protection Operating Mode on
page 5-37for 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 5-34
for more information.
This message displays and a chime sounds if the
engine cooling system reaches unsafe temperatures for
operation. Stop and turn off the vehicle as soon as it
is safe to do so to avoid severe damage. This message
clears when the engine has cooled to a safe operating
temperature.
ENGINE POWER IS REDUCED
This message displays and a chime sounds when the
cooling system temperature gets too hot and the engine
further enters the engine coolant protection mode.
SeeEngine Overheating on page 5-34for further
information.
3-68

If No Steam Is Coming From The
Engine Compartment
The ENGINE OVERHEATED STOP ENGINE or the
ENGINE OVERHEATED IDLE ENGINE message, along
with a low coolant condition, can indicate a serious
problem.
If you get an engine overheat warning, but see or hear
no steam, the problem may not be too serious.
Sometimes the engine can get a little too hot when you:
Climb a long hill on a hot day.
Stop after high-speed driving.
Idle for long periods in traffic.
Tow a trailer. SeeTowing a Trailer on page 4-51.If you get the ENGINE OVERHEATED STOP ENGINE or
the ENGINE OVERHEATED IDLE ENGINE message
with no sign of steam, try this for a minute or so:
1. Turn the air conditioning off.
2. Turn the heater on to the highest temperature and
to the highest fan speed. Open the windows as
necessary.
3. If you are stopped in a traffic jam, apply the brake,
shift to N (Neutral); otherwise, shift to the highest
gear while driving—D(Drive) or 3 (Third).
If the temperature overheat gage is no longer in the
overheat zone or an overheat warning no longer displays,
the vehicle can be driven. Continue to drive the vehicle
slow for about 10 minutes. Keep a safe vehicle distance
from the car in front of you. If the warning does not come
back on, continue to drive normally.
If the warning continues, pull over, stop, and park the
vehicle right away.
If there is no sign of steam, idle the engine for
ve minutes while parked. If the warning is still
displayed, turn off the engine until it cools down.
Also, see “Overheated Engine Protection Operating
Mode” later in this section.
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Overheated Engine Protection
Operating Mode
If an overheated engine condition exists and the
REDUCED ENGINE POWER message is displayed, an
overheat protection mode which alternates ring groups
of cylinders helps prevent engine damage. In this mode,
you will notice a loss in power and engine performance.
This operating mode allows the vehicle to be driven to a
safe place in an emergency. Driving extended miles (km)
and/or towing a trailer in the overheat protection mode
should be avoided.
Notice:After driving in the overheated engine
protection operating mode, to avoid engine damage,
allow the engine to cool before attempting any repair.
The engine oil will be severely degraded. Repair the
cause of coolant loss, change the oil and reset the oil
life system. SeeEngine Oil on page 5-15.
Engine Fan Noise
If the 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 the 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 the
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.
5-37

(C) Aspect Ratio:A two-digit number that
indicates the tire height-to-width measurements.
For example, if the tire size aspect ratio is 75, as
shown in item C of the light truck (LT-Metric) tire
illustration, it would mean that the tire’s sidewall is
75 percent as high as it is wide.
(D) Construction Code
:A letter code is used to
indicate the type of ply construction in the tire. The
letter R means radial ply construction; the letter D
means diagonal or bias ply construction; and the
letter B means belted-bias ply construction.
(E) Rim Diameter
:Diameter of the wheel in
inches.
(F) Service Description
:The service description
indicates the load range and speed rating of a
tire. The load index represents the load carry
capacity a tire is certied to carry. The load index
can range from 1 to 279. The speed rating is
the maximum speed a tire is certied to carry a
load. Speed ratings range from A to Z.
Tire Terminology and Denitions
Air Pressure:The amount of air inside the
tire pressing outward on each square inch of the
tire. Air pressure is expressed in pounds per
square inch (psi) or kilopascal (kPa).
Accessory Weight
:This means the combined
weight of optional accessories. Some examples of
optional accessories are, automatic transmission,
power steering, power brakes, power windows,
power seats, and air conditioning.
Aspect Ratio
:The relationship of a tire’s height
to its width.
Belt
:A rubber coated layer of cords that is
located between the plies and the tread. Cords
may be made from steel or other reinforcing
materials.
Bead
:The tire bead contains steel wires wrapped
by steel cords that hold the tire onto the rim.
Bias Ply Tire
:A pneumatic tire in which the plies
are laid at alternate angles less than 90 degrees
to the centerline of the tread.
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