2005 GMC YUKON XL air conditioning

If the driver’s and passenger’s temperature settings
are not the same, the opposite side temperature
setting will be displayed for an additional
ve seconds. To make the passenger’s temperature
the same as the driver’s press and hold the
AUTO button for about four seconds.
When auto is selected, the air conditioning operation
and air inlet will be automatically controlled. The
air conditioning compressor will run when the
outside temperature is over about 40°F (4°C). The
air inlet will normally be set to outside air. If it’s
hot outside, the air inlet may automatically switch to
recirculate inside air to help quickly cool down
your vehicle. The light on the button will illuminate
in recirculation.
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. Turn the driver’s or
passenger’s side temperature knob 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 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.
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.
9(Off):Press this button to turn off the entire 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. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is off.
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Manual Operation
You may manually adjust the air delivery mode or
fan speed.
w9x(Fan):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.
Pressing this button when the system is off will turn the
system on.
C(Mode):Press this button to manually change the
direction of the airow in your vehicle. Keep pressing the
button until the desired mode appears on the display.
If you press the mode button to select an air delivery
mode, the display will change to show you the selected
air mode delivery. The display will then show the current
status of the system. When the system is turned off, the
display will go blank after displaying the current status of
the system.
H(Panel):This setting will deliver air to the
instrument panel outlets.
)(Bi-Level):This setting will deliver warmer air to the
oor and cooler air to the instrument panel outlets.
6(Floor):This setting will deliver air to the oor
outlets.
-(Defog):See “Defogging and Defrosting” later in
this section.
@(Recirculation):Press this button to limit the
amount of outside air entering your vehicle. The light on
the recirculation button will glow. 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
vehicle. The light on the recirculation button will go off.
Pressing this button also cancels the auto recirculation
feature. To resume the auto recirculation function, press
the AUTO button. Each time the vehicle is started, the
system will revert to the auto recirculation function.
If you select recirculation while in defrost, defog or oor,
the light in the button will ash and then go out to let you
know that this is not allowed. This is normal and helps 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.
You may also notice that the A/C compressor will run
while in recirculation mode. This is normal and helps to
prevent fogging.
3-23

#(Air Conditioning):Press this button to turn the
air conditioning (A/C) compressor on and off. The
snowake symbol will appear on the display when the
A/C is on and will turn off when the air conditioning is off.
Pressing this button when the outside temperature is
too cool for air conditioning to be effective will make the
snowake symbol ash three times and then turn off
to let you know that 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 snowake
symbol will turn off to let you know that the air
conditioning mode has been canceled.
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, defog or recirculation,
the A/C snowake symbol will turn off, but the A/C
compressor will still run to help prevent fogging.
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.
On cool, but sunny days while using manual operation of
the automatic system, use bi-level to deliver warm air to
the oor and cooler air to the instrument panel outlets. To
warm or cool the air delivered, turn the temperature knob
to the desired setting.In AUTO mode the system will cool and dehumidify the
air inside the vehicle. Also while in AUTO mode, the
system will maximize its performance by using
recirculation as necessary.
9(Off):Press this button to turn off the entire 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. The temperature can also
be adjusted using either temperature knob. Press the up
or down arrows on the fan switch, the defrost button, the
AUTO button, or the air conditioning button to turn the
system on when it is off.
Defogging and Defrosting
You can use either defog or front defrost to clear fog or
frost from your windshield. Use the defog mode to clear
the windows of fog or moisture. Use the front defrost
button to defrost the front windshield.
-(Defog):Use this setting to clear the windows of fog
or moisture. Press the mode button to select this
setting. This setting will deliver air to the oor and
windshield outlets.
3-24

0(Defrost):Press this button to defrost the
windshield. The system will automatically control the fan
speed if you select defrost from AUTO mode. 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.
Rear Window Defogger
If your vehicle has this feature, the lines you see on the
rear window warm the glass. The rear window defogger
uses a warming grid to remove fog from the rear window.
<(Rear):Press this button to turn the rear window
defogger on or off. An indicator light in the button
will come on to let you know that the rear window
defogger is activated.
The rear window defogger will turn off about 10 minutes
after the button is pressed. If you need additional
warming time, press the button again.
If your vehicle is equipped with heated mirrors this
button will activate them.
Notice:Using a razor blade or sharp object to clear
the inside rear window may damage the rear
window defogger. Repairs would not be covered by
your warranty. Do not clear the inside of the rear
window with sharp objects.
Outlet Adjustment
Your vehicle has air outlets located in the center and on
the side of your instrument panel that allow you to adjust
the direction and amount of airow inside the vehicle.
Move the louvers up or down. Use the thumbwheel next
to or underneath the outlet to close the louvers. For the
most efficient airow and temperature control, keep the
outlet in the fully opened position.
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.
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, etc., may affect
the performance of the heating and air conditioning
system. Check with your dealer before adding
equipment to the outside of your vehicle.
3-25

Rear Climate Control System
With this system the front or rear passengers can
control the air temperature, air ow and fan speed for
the rear seat passengers. The front overhead console
and the rear controls are used to adjust the climate.
Driver Overhead Control
AUX:Turn the knob, located on the left side of the
control panel, to this position to allow the rear seat
passengers to have control over the rear climate control
system. See “Rear Passenger Console Control” later
for more information.
9(Off):Turn the knob, located on the left side of the
control panel, to this position to turn the rear climate
control system off.
9(Fan):To adjust the airow speed, turn the fan
knob located on the left side of the control panel to the
desired setting. Choose AUTO if you want the system
to automatically choose the fan speed to maintain
a selected temperature. See “Auto Mode” later in this
section for more information on using this feature.
°F (°C):To adjust the air temperature, turn the
temperature knob on the center of the control panel. For
cooler or warmer air turn the knob counterclockwise
toward 66°F (19°C) or clockwise toward 82°F (27°C).
To regulate the airow direction, adjust the right knob on
the control panel. Turn the knob clockwise for oor vent
airow or counterclockwise for headliner vent airow.
Generally, the upper vents are used for air conditioning
and the oor vents for heating. The knob can be set to
any blend setting. Choose AUTO if you want the system
to automatically regulate the airow. See “Auto Mode”
later in this section for more information on using this
feature. Front Controls
3-26

Engine Fan Noise
If your vehicle is equipped with 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 is equipped with 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 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.
Power Steering Fluid
SeeEngine Compartment Overview on page 5-12for
power steering uid reservoir location.
5-35

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 Ination 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 5-62.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, seeLoading
Your Vehicle on page 4-44.
GAWR FRT:Gross Axle Weight Rating for the front
axle, seeLoading Your Vehicle on page 4-44.
GAWR RR:Gross Axle Weight Rating for the rear axle,
seeLoading Your Vehicle on page 4-44.
Intended Outboard Sidewall:The side of an
asymmetrical tire, that must always face outward when
mounted on a vehicle.
KiloPascal (kPa):The metric unit for air pressure.
Light Truck (LT-Metric) Tire:A tire used on light duty
trucks and some multipurpose passenger vehicles.
5-60

Fuses Usage
PCM 1 Powertrain Control Module
ETC/ECMElectronic Throttle Control,
Electronic Brake Controller
IGN EInstrument Panel Cluster, Air
Conditioning Relay, Turn
Signal/Hazard Switch, Starter
Relay
RTD Ride Control
TRL B/U Backup Lamps Trailer Wiring
PCM BPowertrain Control Module,
Fuel Pump
F/PMP Fuel Pump (Relay)
B/U LPBack-up Lamps, Automatic
Transmission Shift Lock
Control System
RR DEFOG Rear Window Defogger
HDLP-HI Headlamp High Beam Relay
PRIME Not Used
AIRBAGSupplemental Inatable
Restraint System
FRT PARKFront Parking Lamps,
Sidemarker Lamps
DRLDaytime Running Lamps
(Relay)
SEO IGN Rear Defog Relay
TBC IGN1 Truck Body Controller IgnitionFuses Usage
HI HDLP-LT High Beam Headlamp-Left
LH HID Not Used
DRL Daytime Running Lamps
RVC Regulated Voltage Control
IPC/DICInstrument Panel
Cluster/Driver Information
Center
HVAC/ECAS Climate Control Controller
CIG LTR Cigarette Lighter
HI HDLP-RT High Beam Headlamp-Right
HDLP-LOW Headlamp Low Beam Relay
A/C COMP Air Conditioning Compressor
A/C COMPAir Conditioning Compressor
Relay
RR WPR Rear Wiper/Washer
RADIO Audio System
SEO B1Mid Bussed Electrical Center,
HomeLink, Rear Heated
Seats
LO HDLP-LT Headlamp Low Beam-Left
BTSIBrake Transmission Shift
Interlock System
CRNK Starting System
LO HDLP-RT Headlamp Low Beam-Right
FOG LP Fog Lamp Relay
5-112