
When it begins to get dark, the automatic headlamp
system will switch from DRL to the headlamps or the last
chosen headlamp setting that was used.
When you turn the headlamp switch off, the headlamps
will go off, and your DRL lamps will illuminate,
provided it is not dark outside.
Shifting the transmission into PARK (P) will allow you to
idle the vehicle with the DRL off. The DRL will stay
off until you shift the transmission out of PARK (P).
This procedure applies only to vehiclesfirst sold in the
United States.
Fog Lamps
If your vehicle has fog lamps, use them for better vision
in foggy or misty conditions.
The fog lamp button is
located on the left side of
the instrument panel.Your parking lamps and/or low-beam headlamps must
be on for your fog lamps to work.
Press the button to turn the fog lamps on. Press the
button again to turn them off. An indicator light will glow
in the button when the fog lamps are on.
Remember, fog lamps alone will not give off as much
light as your headlamps. Never use your fog lamps
in the dark without turning on your headlamps.
The fog lamps will go off whenever your high-beam
headlamps come on. When the high beams go off, the
fog lamps will come on again.
The fog lamps will be cancelled after the ignition is
turned off. If you still want to use the fog lamps after you
restart the vehicle, you will need to press the fog
lamp button again.
Auxiliary Roof Mounted Lamp Switch
If your vehicle has this feature, this switch includes
wiring provisions for a dealer or a qualified service
center to install an auxiliary roof lamp.
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2003 - Yukon/Yukon XL 

This switch is located on
the center of the
instrument panel near the
comfort controls.
When the switch wiring is connected to an auxiliary roof
mounted lamp, pressing the switch will activate the lamp
and illuminate an indicator light near the switch. Pressing
the switch again will turn off the roof mounted lamp.
Interior Lamps
Instrument Panel Brightness
D
:This feature controls the brightness of the
instrument panel lights.
The thumbwheel for this feature is located next to the
headlamp control.Turn the thumbwheel up to adjust the instrument panel
lights. Turn the thumbwheel up to return the radio
display to full brightness when the headlamps or parking
lamps are on. To turn on the dome lamps, turn the
thumbwheel all the way up.
Exit Lighting
With exit lighting, the interior lamps will come on when
you remove the key from the ignition. The lights will
not come on if the dome override button is pressed in.
Entry Lighting
Your vehicle is equipped with an illuminated entry
feature.
When the doors are opened, the dome lamps will come
on if the dome override button is in the out position.
If the dome override button is pressed in, the lamps will
not come on.
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2003 - Yukon/Yukon XL 

Ashtrays and Cigarette Lighter
The front ashtray is located near the center of the
instrument panel or on the front console, if equipped.
Pull on the ashtray door to open it.
Notice:Don’t put papers or other  ammable items
into your ashtrays. Hot cigarettes or other smoking
materials could ignite them, causing a damaging  re.
To remove the front ashtray pull the ashtray up.
To use the cigarette lighter, push it in all the way, and
let go. When it’s ready, it will pop back out by itself.
Notice:Don’t hold a cigarette lighter in with your
hand while it is heating. If you do, it won’t be able to
back away from the heating element when it’s
ready. That can make it overheat, damaging the
lighter and the heating element.
Climate Controls
Climate Control System
Fan Knob
The fan knob on the left side of the control panel
adjusts the fan speed. To increase airflow, turn the knob
clockwise. To decrease airflow, turn it counterclockwise.
To turn the fan off, turn the knob to the off position.
9(Off):If the fan is off, outside air will still enter the
vehicle, and will be directed based on the position of
the mode knob. The temperature can also be adjusted
using the temperature knob.
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2003 - Yukon/Yukon XL 

Temperature Knob
The middle knob on the control panel lets you select the
temperature of the airflowing 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.
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
instrument panel outlets.
)(Bi-Level):Air is delivered through thefloor outlets
as well as the instrument panel outlets. Theflow can
be divided between vent andfloor outlets depending
upon where the knob is placed between the settings.
6(Floor):This setting directs most of the air through
thefloor outlets, and the rest of the air is divided
between the windshield defroster outlets and the side
window defroster outlets.
W(Defog):Airflow is delivered through thefloor
outlets, the windshield defroster outlets and the side
window defroster outlets. The airflow can be divided
betweenfloor and defrost depending upon where
the knob is placed between the settings.
1(Defrost):This setting directs most air through the
windshield defroster outlets, side window defroster
outlets and some through thefloor outlets.
Dual Climate Control System
With this system you can control the heating, cooling
and ventilation for your vehicle.
9(Fan):Turn the left knob clockwise or
counterclockwise to increase or decrease the fan speed.
Turn the knob to the off position to turn off the fan. If
the knob is in off outside air will still enter the vehicle,
and will be directed based on the position of the
mode knob. The temperature can also be adjusted
using the temperature levers.
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2003 - Yukon/Yukon XL 

Turn the right knob clockwise or counterclockwise to
direct the airflow inside of your vehicle.
To change the current mode, select one of the following:
H(Vent):This mode directs air to the instrument
panel vents.
)(Bi-Level):This mode directs half of the air to the
instrument panel vents; then directs most of the
remaining air to thefloor vents. A little air is directed
toward the windshield and the side window vents. Cooler
air is directed to the upper vents and warmer air to
thefloor vents.
6(Floor):This mode directs most of the air to the
floor vents with a little air directed to the windshield and
the side window vents.
h(Recirculation):The recirculation mode is used
to recirculate the air inside of your vehicle. Use this
mode to help prevent outside odors and/or dust
from entering your vehicle or to help cool the air inside
of your vehicle more quickly. Press this button to
turn the recirculation mode on or off. The light on the
recirculation button will illuminate. Recirculation cannot
be used infloor, blend or defrost modes. An indicatoron the button will light up,flash three times and turn off
when recirculation is selected in these modes.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 blend or defrost
mode and increase fan speed.
Temperature Control
Driver’s Side:The lever on the left side of the climate
control panel is used to raise or lower the temperature on
the driver’s side of the vehicle. This lever also adjusts the
temperature to the center console outlets (if equipped).
Passenger’s Side:The lever on the right side of the
climate control panel is used to raise or lower the
temperature on the passenger’s side of the vehicle.
#(Air Conditioning):Press this button to turn
the air-conditioning system on or off. When the button is
pressed, an indicator light will come on and the
system will begin to cool and dehumidify the air inside
of your vehicle. You may notice a slight change in
engine performance when the air conditioning
compressor shuts off and turns on again. This is
normal.
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2003 - Yukon/Yukon XL 

Outlet Adjustment
Use the air outlets located in the center and on the side
of your instrument panel to direct the airflow.
Your vehicle has air outlets that allow you to adjust the
direction and amount of airflow 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 airflow and temperature control, keep
the outlet in the fully opened position.
Rear seat outlets can be used to adjust airflow toward
either seating area, thefloor or upward. Move the center
louvers up or down to direct the airflow.
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 deflectors, 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.
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2003 - Yukon/Yukon XL 

Automatic Operation
AUTO (Automatic):When automatic operation is
active the system will control 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 will change to
show the current driver’s set temperature, delivery
mode and fan speed. Press the AUTO button again
withinfive seconds to display the passenger’s set
temperature.
If the driver and passenger’s temperature settings
are not the same, the opposite side temperature
setting will be displayed for an additionalfive
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.
Tofind 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’sor
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.
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2003 - Yukon/Yukon XL 

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 thefloor. 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.
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 airflow 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
floor and cooler air to the instrument panel outlets.
6(Floor):This setting will deliver air to thefloor
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 orfloor,
the light in the button willflash and then go out to let you
know that this is not allowed. This is normal and helps to
prevent fogging.
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2003 - Yukon/Yukon XL