2004 GMC YUKON Owner's Manual

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
Use the air outlets located
in the center and on the
side of your instrument
panel to direct the airow.
Your vehicle has air outlets 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.
Rear seat outlets can be used to adjust airow toward
either seating area, the oor or upward. Move the center
louvers up or down to direct the airow.
3-33

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.
Rear Air Conditioning System
If your vehicle is equipped with the optional rear air
conditioner it has two rear air conditioning fan speed
selectors. One fan speed selector is located in the
overhead console and the other is located in the
headliner above the second row seats.
To increase and decrease the ow of cooled air to the
rear vents, turn the knob to the fan speed you want.Front Control
3-34

The knob has three speed positions. To increase the
ow of cooled air, turn the knob clockwise. To decrease
the ow of cooled air, turn it counterclockwise. To
turn the fan off, turn the knob to the off position.
To operate the rear system using the front control, just
turn the knob to the fan position you want.
To use the rear control, rst turn the front control to the
AUX position. Then, the rear control can be used to
increase and decrease the airow.Rear Air Conditioning and Heating
System
If your vehicle is equipped with this system, there are
two rear heat and air conditioning controls. One control
is located in the overhead console and the other is
located in the headliner above the second row seats.
The system can be controlled from the front controls as
well as the rear controls.
The front control has three knobs that control airow
speed, temperature and airow location. Rear Control
Front Control
3-35

Fan Knob
The fan knob on the left side of the control panel
adjusts the fan speed. To increase airow, turn the knob
clockwise. To decrease airow, turn it counterclockwise.
To turn the fan off, turn the knob to the off position.
9(Off):An off setting, located on the front climate
control panel also allows the driver to turn off the
rear seat passenger seat controls from the front seat.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air owing 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
headliner outlets.
)(Bi-Level):Air is delivered through the oor outlets
as well as the headliner outlets. The ow can be
divided between vent and oor outlets depending upon
where the knob is placed between the settings.
6(Floor):This setting directs most of the air through
the oor outlets.
To use the rear control, rst turn the front control to the
AUX position. Then, the rear control can be used to
adjust the airow speed, temperature, and airow
location.Rear Controls
3-36

Fan Knob
The fan knob on the left side of the control panel
adjusts the fan speed. To increase airow, turn the knob
clockwise. To decrease airow, turn it counterclockwise.
To turn the fan off, turn the knob to the off position.
9(Off):Turn the knob to this position to turn the rear
seat comfort controls on or off.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air owing 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
headliner outlets.
)(Bi-Level):Air is delivered through the oor outlets
as well as the headliner outlets. The ow can be
divided between vent and oor outlets depending upon
where the knob is placed between the settings.
6(Floor):This setting directs most of the air through
the oor outlets.
3-37

Rear Air Conditioning and Heating
System and Electronic Climate
Controls
With this system the front or rear passengers can
control the air temperature, air ow and fan speed for
the rear seat passengers. The climate control has
an overhead control near the driver and a control on the
back of the center console.
Driver Overhead Control
To control the rear climate control from the front seat
position, use the driver overhead control. The rear
console control must be on.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
3-38

Rear Passenger Console Control
To control the rear climate control from the rear
passenger seat position, use the rear passenger console
control. The driver overhead control fan knob must be
set to the AUX position.
The rear seat controls have the following settings:
O(On/Off):Press this button to turn the rear seat
comfort controls on or off when the front overhead
control is set to AUX.
%(Mode):Press this button to select the air delivery
mode and AUTO mode. 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.
b(Temperature):Press this button up or down to
increase or decrease the temperature setting.
w9x(Fan):Press this button up or down to adjust
the fan speed. 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.
AUTO Mode
When using the system in auto mode, nd your comfort
setting by placing the temperature control to 74°F
(23°C) and allowing about 20 minutes for the system to
regulate. Then adjust the temperature setting as
necessary. If you choose full cold 60° F (15°C), the
system will remain at the maximum cooling setting. If
you choose full hot 90 F (32°C), the system will remain
at the maximum heat setting. Rear Controls
3-39

Warning Lights, Gages and
Indicators
Warning Lights, Gages, and
Indicators
This part describes the warning lights and gages that may
be on your vehicle. The pictures will help you locate them.
Warning lights and gages can signal that something is
wrong before it becomes serious enough to cause
an expensive repair or replacement. Paying attention to
your warning lights and gages could also save you
or others from injury.
Warning lights come on when there may be or is a
problem with one of your vehicle’s functions. As you will
see in the details on the next few pages, some
warning lights come on briey when you start the
engine just to let you know they’re working. If you are
familiar with this section, you should not be alarmed
when this happens.Gages can indicate when there may be or is a problem
with one of your vehicle’s functions. Often gages
and warning lights work together to let you know when
there’s a problem with your vehicle.
When one of the warning lights comes on and stays on
when you are driving, or when one of the gages shows
there may be a problem, check the section that tells you
what to do about it. Please follow this manual’s advice.
Waiting to do repairs can be costly – and even
dangerous. So please get to know your warning lights
and gages. They’re a big help.
Your vehicle also has a driver information system that
works along with the warning lights and gages. See
Driver Information Center (DIC) on page 3-58.
3-40