2001 GMC YUKON Owner's Manual

3-9
Rear Air Conditioning and Rear Heater
(If Equipped)
If your vehicle has the rear air conditioning and rear
heater system combination, controls are provided to
regulate temperature, location and fan speed.
Front Control
To adjust the airflow speed, turn the fan control knob
located on the left side to the desired setting.
To activate the second seat control system, turn the fan
knob on the front overhead control to REAR.
To regulate the airflow location, adjust the right control
on the control. Turn the knob clockwise for floor vent
airflow or counterclockwise for headliner vent airflow. Generally, the upper vents are used for air conditioning
and the floor vents for heating. The control knob can be
set to any blend setting.
To adjust the air temperature, turn the temperature knob
on the center of the control panel.
For warmer air, turn the knob clockwise toward red. For
cooler air, turn the knob counterclockwise toward blue.
Rear Control
The rear control works just like the front control. It will
allow second seat passengers to adjust the controls as
they desire. To use the rear control, first turn the front
control knob to REAR.

3-10 Rear Air Conditioning and Heating Systems
with Electronic Climate Control System
(If Equipped)
Front Control
Rear ControlWith this system the rear passengers can control the
temperature of the air flow for his/her own zones.
The climate control has three controls.
To adjust the airflow speed, turn the fan control knob
located on the left side of the control panel to the desired
blower setting.
The system also has a front AUTO setting that can
automatically change the temperature of the rear seating
area based on information from the front control. An
OFF setting, located on the front climate control panel,
also allows the driver to turn off the rear passenger seat
controls from the front seat.
To adjust the air temperature, turn the temperature knob
on the center of the control panel.
For warmer air, turn the knob clockwise toward
82
F (28
C). Turn the knob counterclockwise
toward 66
F (19
C) for cooler air.
To regulate the airflow location, adjust the right knob on
the control panel. Turn the knob clockwise for floor vent
airflow or counterclockwise for headliner vent airflow.
Generally, the upper vents are used for air conditioning
and the floor vents for heating. The control knob can be
set to any blend setting.
For rear control operation, use the above instructions.

3-11 Air Conditioning
On hot days, open the windows long enough to let hot
air inside 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.
The RECIRCULATION button allows the air inside
your vehicle to be recirculated. This setting helps to
maximize your air conditioner's performance and your
vehicle's fuel economy. This setting also cools air the
fastest and can be used to keep unwanted odors and/or
dust from entering the vehicle. When using the air
conditioner, turn off the RECIRCULATION button after
the vehicle reaches a comfortable interior temperature.
When the right knob on the control panel is between
HEATER and DEFROST, the recirculation feature will
not function to reduce window fogging.The A/C button, below the mode knob, allows the air
coming into your vehicle to be cooled. This setting is
useful for normal cooling on hot days. When you use
A/C with the RECIRCULATION button pushed in,
turn off recirculation as soon as the vehicle reaches a
comfortable interior temperature.
Maximum air conditioning performance is obtained by
pressing the A/C button, the RECIRCULATION button
and turning the temperature knob fully counterclockwise
to the blue area. This setting also cools air the fastest.
After the vehicle's interior reaches a comfortable
temperature, press the OUTSIDE AIR button to
place the air conditioning system in the normal mode.
Passenger Compartment Air Filter (If Equipped)
If your vehicle has air conditioning, it is equipped with
a passenger compartment air filter, which filters outside
air entering the vehicle. For information on replacing
the filter see ªPassenger Compartment Air Filterº in
the Index.

3-12 Heating
The heater works best if you keep your windows closed
while using it. On cold days, use the HEATER or
VENT/HEAT setting with the temperature knob in
the red area.
On cold days, approximately 32
F (
-0
C) or lower, if
your vehicle is equipped with an automatic transmission,
you may experience differences in how the transmission
shifts until the engine is warm. This feature automatically
reduces the time it takes for the engine to reach normal
operating temperature and shortens the time it takes the
heater to reach full output.
If you use the engine coolant heater before starting your
engine in cold weather, 20
F (
-8
C) or lower, the
heating system will produce warmer air faster to heat the
passenger compartment.
The use of an engine coolant heater also reduces the
time it takes for the engine to reach normal operating
temperature. For more information, see ªEngine Coolant
Heaterº in the Index.
Defogging and Defrosting
On cool, humid days, use DEFOG to keep the windshield
and side windows clear. Use DEFROST to remove fog
or ice from the windshield in extremely humid or cold
conditions. Use DEFROST with the temperature knob
toward the red area and the fan control turned all the
way to the right.
Rear Window Defogger (If Equipped)
If you see lines running across the rear window, you
have a rear window defogger. The lines warm the glass.
To turn on the rear window
defogger, press this button
located next to the mode
control knob.
The rear window defogger will only work if the ignition
is in RUN. For best results, clear the window of as much
snow or ice as possible first.

3-13
The defogger will shut itself off after several minutes.
If you need additional warming time, press the button
again. You can turn the defogger off at any time by
pressing the button.
If your vehicle is equipped with heated outside mirrors,
the rear window defogger button will also activate the
heated outside mirrors.
Do not attach a temporary vehicle license, tape or decals
across the defogger grid on the rear window.
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 warming grid, and the
repairs wouldn't be covered by your warranty.
Ventilation System
For mild outside temperatures when little heating or
cooling is needed, use VENT to direct outside air
through your vehicle. Air will flow through the
instrument panel outlets.
Your vehicle's ventilation system supplies outside
air to the inside of your vehicle when it is moving.
With the side windows closed, air will flow into the
front air inlet grilles, through the vehicle, and out
the air exhaust valves.
Outside air will also enter the vehicle when the heater
or the air conditioning fan is running, unless you have
the RECIRCULATION button pushed in. For more
information on the RECIRCULATION button,
see ªAir Conditioningº earlier in this section.

3-14
Your vehicle has air outlets
in the center and on the
sides of the instrument
panel and also may be
equipped on the headliner.
You can turn the outlets from side
-to-side or up
and down to direct the flow of air. The left driver
and passenger outlets on vehicles equipped with air
conditioning have shut off knobs. Turn the knob to the
left to shut off air flow or to the right to allow air flow.
When you close an outlet, it will increase the flow of air
coming out of any outlets that are open. The center
outlet does not completely shut off airflow.Ventilation Tips

Keep the hood and front air inlet 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.

When you enter a vehicle in cold weather, turn the
fan knob all the way to the right 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.

The use of hood air deflectors may adversely
affect the performance of the heating and air
conditioning system.

3-15
Audio Systems
Your audio system has been designed to operate easily
and give years of listening pleasure. You will get the
most enjoyment out of it if you acquaint yourself with it
first. Find out what your audio system can do and how
to operate all its controls, to be sure you're getting the
most out of the advanced engineering that went into it.
Setting the Clock for Systems with
SET Button
Press SET. Within five seconds, press and hold the
SEEK right arrow until the correct minute appears on
the display. Press and hold the SEEK left arrow until
the correct hour appears on the display.
Setting the Clock for Systems with
HR and MN Buttons
Press and hold HR until the correct hour appears on
the display. Press and hold MN until the correct minute
appears on the display. To display the clock with the
ignition off, press RECALL or HR/MN and the time
will be displayed for a few seconds. There is an initial
two
-second delay before the clock goes into the
time
-set mode.
AM-FM Stereo
Playing the Radio
VOLUME: This knob turns the system on and off and
controls the volume. To increase volume and turn the radio
on, turn the knob clockwise. Turn it counterclockwise to
decrease volume and turn the radio off.
RECALL: Display the time with the ignition off by
pressing the recall knob. When the radio is playing,
press this knob to recall the station frequency.
Finding a Station
AM
-FM: Press the lower knob to switch between AM
and FM. The display shows your selection.
TUNE: Turn the lower knob to tune in radio stations.

3-16
SEEK: Press the right arrow to tune to the next higher
station and the left arrow to tune to the next lower
station and stay there.
SCAN: Select either AM, FM1 or FM2 mode and press
both SEEK buttons to listen to a few seconds of each
radio station. SCAN will light up on the display. The
radio will automatically SCAN to the next higher station,
play that station for a few seconds, then SCAN to
the next higher station. Press VOLUME or both
SEEK buttons to stop scanning.
PUSHBUTTONS: The four numbered pushbuttons
let you return to your favorite stations. You can set up
to 14 stations (seven AM and seven FM). Just:
1. Turn the radio on.
2. Press AM
-FM to select the band.
3. Tune in the desired station.
4. Press SET. (SET will appear on the display.)
5. Press one of the four pushbuttons within five seconds.
Whenever you press that numbered button, the station
you set will return.
6. Repeat the steps for each pushbutton.In addition to the four stations already set, up to three
more stations may be preset on each band by pressing
two adjoining buttons at the same time. Just:
1. Tune in the desired station.
2. Press SET. (SET will appear on the display.)
3. Press two adjoining buttons at the same time,
within five seconds. Whenever you press the same
two buttons, the station you set will return.
4. Repeat the steps for each pair of pushbuttons.
Setting the Tone
BASS: Slide this lever up or down to increase or
decrease bass.
TREB: Slide this lever up or down to increase or
decrease treble. If a station is weak or noisy, you may
want to decrease the treble.
Adjusting the Speakers
BAL: Turn the control behind the upper knob to move
the sound to the left or right speakers. The middle position
balances the sound between the speakers.
FADE: Turn the control behind the lower knob to move
the sound to the front or rear speakers. The middle position
balances the sound between the speakers.