light GMC YUKON 2003 Service Manual

If you start your vehicle in a dark garage, the automatic
headlamp system will come on immediately. Once
you leave the garage, it will take approximately
one minute for the automatic headlamp system to
change to DRL if it is bright enough outside. During that
delay, your instrument panel cluster may not be as
bright as usual. Make sure your instrument panel
brightness control is in the full bright position. See
“Instrument Panel Brightness Control”underInterior
Lamps on page 3-18.
To idle your vehicle with the automatic headlamp
system off, turn the control to the off position.
You may be able to turn off your Automatic Headlamp
System. See″Daytime Running Lamps (DRL)″later
in this section for more information.
Your headlamps will also stay on after you exit the
vehicle. You can program this feature using the Driver
Information Center. SeeDriver Information Center (DIC)
on page 3-53.
As with any vehicle, you should turn on the regular
headlamp system when you need them.Lamps On Reminder
A reminder chime will sound when your headlamps or
parking lamps are manually turned on and your
ignition is off, in LOCK, ACCESSORY, or your door is
open. To disable the chime, turn the light off then
back on.
Daytime Running Lamps
Daytime Running Lamps (DRL) can make it easier for
others to see the front of your vehicle during the
day. DRL can be helpful in many different driving
conditions, but they can be especially helpful in the short
periods after dawn and before sunset. Fully functional
daytime running lamps are required on all vehicles
first sold in Canada.
The DRL system will come on when the following
conditions are met:
•the ignition is on,
•the exterior lamps control is AUTO,
•the automatic transmission is not in PARK (P),
•the light sensor determines it is daytime and
When the DRL are on, only your DRL lamps will be on.
The taillamps, sidemarker and other lamps won’tbe
on. The instrument panel won’t be lit up either.
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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

Dome Lamps
The dome lamps will come on when you open a door.
You can also turn the dome lamps on by turning
the thumbwheel, located next to the exterior lamps
control, all the way up. In this position, the dome lamps
will remain on whether a door is opened or closed.
E:You can use the dome override button, located
below the exterior lamps control, to set the dome lamps
to come on automatically when a door is opened, or
to remain off. To turn the lamps off, press the button into
the in position. With the button in this position, the
dome lamps will remain off when the doors are open.
To return the lamps to automatic operation, press
the button again and return it to the out position. With
the button in this position, the dome lamps will come on
when you open a door.
Battery Run-Down Protection
This feature shuts off the dome, reading, glove box and
underhood lamps if they are left on for more than
10 minutes when the ignition is off. This will keep your
battery from running down.
Accessory Power Outlets
With accessory power outlets you can plug in auxiliary
electrical equipment such as a cellular telephone or
CB radio.Your vehicle may have two accessory power outlets, or
may have one accessory power outlet located near
the cigarette lighter, if equipped. The cigarette lighter is
designed tofit only in the receptacle to the right of
the accessory power outlet.
To use the outlet, lift the cover. When not using it,
always close the cover.
Certain power accessory plugs may not be compatible
to the accessory power outlet and could result in
blown vehicle or adapter fuses. If you experience a
problem, see your dealer for additional information on
the accessory power plugs.
Notice:Adding some electrical equipment to your
vehicle can damage it or keep other things from
working as they should. This wouldn’t be covered by
your warranty. Check with your dealer before
adding electrical equipment, and never use anything
that exceeds the amperage rating.
When adding electrical equipment, be sure to follow the
proper installation instructions included with the
equipment.
Notice:Power outlets are designed for accessory
plugs only. Do not hang any type of accessory
or accessory bracket from the plug. Improper use of
the power outlet can cause damage not covered
by your warranty.
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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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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

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 choose
from to clear fog or frost from your windshield. Use
the defog mode to clear the windows of fog or moisture
and warm the passengers. Use the defrost mode to
remove fog or frost from the windshield more quickly.
Turn the right knob clockwise or counterclockwise
to select one of the following modes:
-(Defog):This mode directs the air to thefloor outlets,
windshield and the side window vents. The air
conditioning compressor will run automatically to
dehumidify the air to prevent window fogging. The
recirculation mode cannot be selected while in the
defog mode.
1(Defrost):This mode directs most of the air to the
windshield and the side window vents, with only a
little air directed to thefloor vents. The air conditioning
compressor will run automatically to dehumidify the
air to prevent window fogging. The recirculation mode
cannot be selected while in defrost mode.
Do not drive the vehicle until all the windows are clear.
Rear Window Defogger
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 automatically turn off
several minutes after the button is pressed. Pressing the
button while the defogger is running can also turn off
the defogger.
If your vehicle is equipped with heated mirrors this
button will activate them.
Notice:Don’t use anything sharp on the inside of
the rear window. If you do, you could cut or damage
the warming grid, and the repairs wouldn’tbe
covered by your warranty. Do not attach a temporary
vehicle license, tape, a decal or anything similar
to the defogger grid.
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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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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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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:Don’t use a razor blade or something else
sharp on the inside of the rear window. If you
do, you could cut or damage the defogger and the
repairs would not be covered by your warranty.
Do not attach a temporary vehicle license, tape, a
decal or anything similar to the defogger grid.
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.
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