2007 GMC SIERRA air conditioning

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 will remain at the maximum
cooling setting. If you choose the temperature
setting of 90°F (32°C), the system will remain
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 and also turns on your
headlamps. For more information on the solar
sensor, see “Sensors” later in this section.
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.O(On/Off):Press this button to turn off the
climate control system. Outside air will still enter the
vehicle, and will be 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 you adjust the air delivery
mode or temperature settings with the system off,
the display will illuminate briey to show you the
settings and then return 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.
Manual Operation
You may manually adjust the air delivery mode or
fan speed.
y9 z(Fan):The buttons with the fan symbols
allow you to manually adjust the fan speed.
Press the up arrow to increase fan speed and the
down arrow to decrease fan speed.
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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 will ash
three times and then turn off. The air conditioning
compressor will also come 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 will circulate
throughout your vehicle. An indicator light on the
button will come on to let you know 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 let you know 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 let you know 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 you might notice a small amount of
water dripping underneath the vehicle while idling
or after turning off the engine. This is normal.
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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 the mode up and down arrows to 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.
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 will automatically turn
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.
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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.
W(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 176.
Outlet Adjustment
Use the air outlets located in the center and on
the side of the 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
better, reducing the chance of fogging
the inside of your windows.
When you enter a vehicle in cold weather, set
the fan speed to maximum airow for a few
moments before driving. This helps clear
the intake ducts of snow and moisture, and
reduces the chance of fogging the inside
of your windows.
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 the
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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As soon as it is safe to do so, carefully pull your
vehicle over to the side of the road and turn
the ignition off. Check the wiring connection to the
trailer and turn the ignition back on. This
message clears if the trailer is reconnected. This
message also clears if you acknowledge it. If
this message still displays, either your vehicle or
the trailer needs service. See your dealer.
See “Integrated Trailer Brake Control System”
underTowing a Trailer on page 445for more
information.
DRIVER DOOR OPEN
This message displays and a chime sounds if the
driver’s 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 258. 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 as soon as
possible to avoid damage to the engine.
ENGINE OIL LOW ADD OIL
If your vehicle has an oil level sensor, this
message displays if the oil level in the vehicle is
low. Check the oil level and correct it as
necessary. You may need to let the vehicle cool
or warm up and cycle the ignition to be sure
this message clears.
This message clears itself after 10 seconds, until
the next ignition cycle. SeeEngine Oil (Gasoline
Engine) on page 500for additional 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. See
Engine Exhaust on page 167. 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 234
orClimate Control System (Heater
Only) on page 237.
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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(F) Service Description:The service description
indicates the load range and speed rating of a
tire. The load index can range from 1 to 279.
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.
Cold Tire Pressure:The amount of air pressure
in a tire, measured in pounds per square inch
(psi) or kilopascals (kPa) before a tire has built up
heat from driving. SeeInation - Tire Pressure
on page 559.
Curb Weight:This means the weight of a motor
vehicle with standard and optional equipment
including the maximum capacity of fuel, oil, and
coolant, but without passengers and cargo.
DOT Markings:A code molded into the sidewall
of a tire signifying that the tire is in compliance
with the U.S. Department of Transportation (DOT)
motor vehicle safety standards. The DOT code
includes the Tire Identication Number (TIN),
an alphanumeric designator which can also identify
the tire manufacturer, production plant, brand,
and date of production.
GVWR:Gross Vehicle Weight Rating. See
Loading Your Vehicle on page 425.
GAWR FRT:Gross Axle Weight Rating for the
front axle. SeeLoading Your Vehicle on page 425.
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