light GMC YUKON XL DENALI 2001 Service Manual

2-77
Here are some situations you may experience with your
fuel gage. None of these indicate a problem with the
fuel gage.

At the gas station, the fuel pump shuts off before the
gage reads full.

It takes a little more or less fuel to fill up than the
fuel gage indicated. For example, the gage may have
indicated the tank was half full, but it actually took a
little more or less than half the tank's capacity to fill
the tank.

The gage goes back to empty when you turn off
the ignition.
Message Center
The message center is located on the left side of the
instrument panel cluster. It gives you important safety
and maintenance facts. When you turn the ignition on,
the entire center lights up for just a few seconds. As
needed, the message center will display one of the
following messages. The message center is capable
of alternating among different messages if needed.
Battery
If this message is displayed
when the engine is running,
you may have a problem
with your charging system.
The battery display will also stay on while the key is in
RUN until the engine is started.
If the message stays on after starting the engine it could
indicate a problem with the generator drive belt, or some
other charging system problem. Have it checked right
away. Driving with this message displayed could drain
your battery.
If you must drive a short distance with this message
displayed, it helps to turn off all your accessories, such
as the radio and the air conditioner.

3-3
Mode Knob - Automatic Operation
The right knob on the control panel allows you to
choose the direction of air delivery. When the system
is set in AUTO mode, sensors will control the air
delivery mode. Air will come primarily from the floor
or instrument panel outlets, with some air directed to
the windshield to prevent fogging.
When the system is in AUTO mode, the air conditioning
light will turn on, and the recirculation and outside air
lights turn off. With the system in full auto control
(both the fan and mode knobs in AUTO), you still
have the ability to override any function. However,
continually overriding the outside air or the A/C
compressor will limit the ability of the system to
cool the vehicle quickly.
If you push a button for a function which is not
available, the light next to that button will flash
three times to alert you that it's not available.
To find your comfort zone, start with the 74
F (23
C)
setting and allow about 20 minutes for the system to
adjust the temperature if necessary.With the automatic setting, the air conditioning
compressor automatically cycles when needed to cool
the air. In cold weather, when the system senses the need
for heat, the airflow will be directed out of the floor
outlets. As the interior temperature approaches a desired
setting, the fan speed will decrease. To maintain interior
comfort, the airflow will adjust between the instrument
panel air outlets and floor outlets. On bright sunny days
in cool weather, the airflow may come out of the air
conditioning and floor outlets (bi
-level mode) to
maintain comfort and prevent stuffiness.
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 outside air
temperature, engine coolant temperature or the time
since the engine was last started. As the coolant warms
up, the fan speed will gradually increase and air will
flow from the heater outlets, with some airflow to
the windshield to prevent fogging under most
normal conditions.
Be careful not to put anything over the solar sensor
located around the center of the instrument panel.
This sensor is used by the automatic system to
regulate temperature.

3-5
Pressing the recirculation button will cancel outside
air operation. To return to normal system operation and
to prevent stale passenger compartment air, be sure to
return to the outside air position.
Recirculation will not be available in heater, blend or
defrost modes to help reduce window fogging. If the
recirculation button is pressed in theses modes, the
indicator light for recirculation will flash three times
indicating that forced outside air is activated and
recirculation is not available.
If the air conditioning system is activated and system
demand is high in situations such as city traffic, idling,
or very hot weather, the system will automatically
switch from outside air to recirculation. The indicator
light will not change. After demand on the system is
not so great, the system will return back to outside air. A/C: Press this button to turn the air
conditioning on and off. The system will cool and
dehumidify the air inside the vehicle when the A/C light
is on. When in AUTO, the A/C is automatically engaged
when necessary.
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which air
conditioning is ineffective.
Rear Air Conditioning and Heating Systems
Your vehicle is equipped with a rear heating and air
conditioning system that can increase and decrease
airflow and temperature based on passenger needs.
Vehicles equipped with a sunroof will have the manual
control heating and air conditioning system. Vehicles
without a sunroof will be equipped with the Electronic
Climate Control System

3-12 AM-FM Stereo with Cassette Tape Player
Included with the AM-FM Stereo with Cassette Tape
Player are ten Bose
high performance speakers, an
Acoustimass
bass module and a seven channel Bose
amplifier. Please see your dealer for details.
Playing the Radio
PWR VOL: Press this knob to turn the system on and
off. To increase volume, turn the knob clockwise. Turn
it counterclockwise to decrease volume. The knob is
capable of being turned continuously.
REAR DSPL: When the main radio is turned on, press
this button to turn on the rear seat audio display on the
main radio. Press it again to turn the rear seat audio
display off.RECALL: Display the time with the ignition off by
pressing this button. When the radio is playing, press
this button to recall the station frequency.
SCV: Your system has a feature called
Speed
-Compensated Volume (SCV). With SCV, your
audio system adjusts automatically to make up for road
and wind noise as you drive. Set the volume at the
desired level. Turn the control ring behind the upper
knob clockwise to adjust the SCV. Then, as you drive,
SCV automatically increases the volume, as necessary,
to overcome noise at any particular speed. The volume
level should always sound the same to you as you drive.
If you don't want to use SCV, turn the control all the
way down. Each notch on the control ring allows for
more volume compensation at faster vehicle speeds.
Finding a Station
AM FM: Press this button to switch between AM, FM1
and FM2. The display will show your selection.
TUNE: Press this knob lightly so it extends. Turn it to
choose radio stations. Push the knob back into its stored
position when you're not using it.
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. The sound will mute
while seeking.

3-13
SCAN: Press and hold SEEK for two seconds until
SCAN appears on the display. SCAN allows you to
listen to stations for a few seconds. The receiver will
continue to scan and momentarily stop at each station
until you press the button again. The sound will mute
while scanning.
PUSHBUTTONS: The six numbered pushbuttons let
you return to your favorite stations. You can set up to
18 stations (six AM, six FM1 and six FM2), by
performing the following steps:
1. Turn the radio on.
2. Press AM FM to select the band.
3. Tune in the desired station.
4. Press and hold one of the six pushbuttons. The sound
will mute. When it returns, release the pushbutton.
Whenever you press that numbered pushbutton, the
station you set will return.
5. Repeat the steps for each pushbutton.
P. SCAN: The preset scan button lets you scan through
your favorite stations stored on your pushbuttons.
Select either the AM, FM1 or FM2 mode and then press
P. SCAN. It will scan through each station stored on
your pushbuttons and stop for a few seconds before
continuing to scan through all of the pushbuttons.Press P. SCAN again or one of the pushbuttons to stop
scanning to listen to a specific preset station. P. SCAN
will light up on the display while in this mode. If one of
the stations stored on a pushbutton is too weak for the
location you are in, the radio display will show the
channel number (P1 through P6) for several seconds
before advancing to the next preset station.
Setting the Tone
BASS: Press lightly on this knob to release it from its
stored position. Turn the knob clockwise to increase
bass and counterclockwise to decrease bass.
TREB: Press lightly on this knob to release it from
its stored position. Turn the knob clockwise to increase
treble and counterclockwise to decrease treble. If a
station is weak or noisy, you may want to decrease
the treble.
Push these knobs back into their stored positions when
you're not using them.
Adjusting the Speakers
BAL: Press lightly on this knob to release it from its
stored position. Turn the control clockwise to adjust
sound to the right speakers and counterclockwise to
adjust sound to the left speakers. The middle position
balances the sound between the speakers.

3-14
FADE: Press lightly on this knob to release it from its
stored position. Turn the control clockwise to adjust the
sound to the front speakers and counterclockwise for the
rear speakers. The middle position balances the sound
between the speakers.
Push these knobs back into their stored positions when
you're not using them.
Playing a Cassette Tape
Your tape player is built to work best with tapes that
are up to 30 to 45 minutes long on each side. Tapes
longer than that are so thin they may not work well in
this player.
To load a cassette tape with the ignition off, press
EJECT or RECALL. Then, insert the cassette tape.
If the ignition is on but the radio is off, the tape will
begin playing.
Once the tape is playing, use the VOL, BAL, FADE,
BASS and TREB controls just as you do for the radio.
The tape symbol and a direction arrow will be on the
display whenever a tape is being played. Anytime a
tape is inserted, the top side is selected for play first.
The player automatically senses if the cassette tape is
metal or CrO
2 and adjusts for best playback sound.PREV (1): Press the PREV button or the SEEK left
arrow to search for the previous selection. A minimum
three second blank gap is required for the player to stop
at the beginning of the selection. The tape direction
arrow will blink during the SEEK operation.
PROG (2): Press this button to switch from one side of
the tape to the other.
NEXT (3): Press the NEXT button or the SEEK right
arrow to search for the next selection. A minimum
three second blank gap is required for the player to stop
at the beginning of the selection. The tape direction
arrow will blink during the SEEK operation. The sound
will mute while searching for the next selection.
REV (4): Press this button to rapidly reverse the tape
to the beginning of the cassette or until you press REV
again. The radio will play the last selected station while
reversing the tape. The tape direction arrow will blink
during the reverse operation.

(5): Press this button to reduce cassette tape noise.
The double
-D symbol will appear on the display while
the player is in this mode.
Dolby Noise Reduction is manufactured under a license
from Dolby Laboratories Licensing Corporation. Dolby
and the double
-D symbol are trademarks of Dolby
Laboratories Licensing Corporation.

3-15
FWD (6): Press this button to rapidly forward the tape
to the end of the cassette or until you press FWD again.
The radio will play the last selected station while
forwarding the tape. The tape direction arrow will blink
during the forward operation.
AM FM: Press this button to switch from a tape or CD
to the radio.
CD TAPE: Press this button if you have a tape loaded
in the cassette tape player and the radio is turned on, to
play a tape. Press AM FM to return to the radio when a
tape is playing. Press CD TAPE to switch between the
tape player, remote CD and console
-mounted CD
changer if all are loaded. When a tape is playing, a
lighted arrow will appear on the display and show the
direction of play. (If the radio is turned off, the tape
stays in the player and will resume playing at the point
where it stopped.)
EJECT: Press this button to remove the tape.
The radio will now play. EJECT can be used with either
the ignition or radio off. To load a cassette tape with
the ignition or radio off, press EJECT before loading
the cassette.CLN: If this message appears on the display, the
cassette tape player needs to be cleaned. It will still play
tapes, but you should clean it as soon as possible to
prevent damage to the tapes and player. See ªCare of
Your Cassette Tape Playerº in the Index. After you clean
the player, press and hold EJECT for five seconds to
reset the CLN indicator. The radio will display
--- to
show the indicator was reset.
CD Adapter Kits
It is possible to use a portable CD player adapter kit
with your cassette tape player after activating the bypass
feature on your tape player.
To activate the bypass feature, perform the
following steps:
1. Turn the ignition to RUN or ACCESSORY.
2. Turn the radio off.
3. Press and hold the CD TAPE button for five seconds.
The tape symbol on the display will flash for
two seconds, indicating the feature is active.
4. Insert the adapter into the cassette slot. It will power
up the radio and begin playing.
This override routine will remain active until EJECT
is pressed.

3-16 Rear Seat Audio (RSA)
This feature allows rear seat passengers to listen to and
control any of the music sources, including AM FM,
cassette tapes and CDs, through the Rear Seat Audio
(RSA) controller. However, the rear seat passengers
can only control the music sources that the front seat
passengers are not listening to. For example, rear seat
passengers may listen to a cassette tape through
headphones and have control over the cassette tape
playing while the driver listens to the radio through the
front speakers. If rear seat passengers choose to listen
to the radio while the driver is listening to the radio they
will not be able to control the radio.The rear seat passengers have control of the volume for
each set of headphones. Be aware that the front seat
audio controls always have priority over the RSA
controls. If the front seat passengers switch the source
for the main radio to a remote source, the RSA will play
the same remote source. The rear speakers will be muted
when the RSA power is turned on. You may operate the
RSA functions even when the main radio is off.
The following function is controlled by the knob on the
main radio:
PWR VOL: Push this knob twice to turn RSA off.
The following functions are controlled by the RSA
system buttons:
PWR: Press this button to turn RSA on or off.
VOL: Press this knob lightly so it extends. Turn
the knob clockwise to increase volume and
counterclockwise to decrease volume. Push the knob
back into its stored position when you're not using it.
The upper VOL knob controls the upper headphone and
the lower VOL knob controls the lower headphone.

3-18 Compact Disc Changer
The compact disc changer plays up to six standard size
CDs continuously. Individual CDs may be loaded or
ejected into or from any position.
A green light on each numbered button indicates a CD is
loaded in the respective position. An amber light on a
numbered button indicates that a CD is playing. When
loading CDs, the loading slot indicators turn amber to
indicate that the player is ready to accept a CD. CDs can
be loaded or ejected with the radio or the ignition being
on or off.You must load CDs with the label side up. If you do not,
the player will automatically eject the CDs.
NOTICE:
Loading CDs with adhesive labels will damage
the player.
To load a CD perform the following steps:
1. Press the LOAD button. Available positions will
blink amber.
2. Select a position by pressing the desired numbered
button with the amber blinking light. If a button is
not pressed within five seconds, the changer will go
to the lowest available position.
3. Load the CD when the loading slot indicators turn
amber. An internal door will open allowing a single
CD to be inserted into the changer. After
approximately ten seconds the changer will be
ready to play.

3-19
To load two or more CDs perform the
following steps:
1. Press and hold the LOAD button. The first CD will
be loaded into the lowest numbered empty position.
2. Load a single CD when the loading slot indicators
turn amber. After about ten seconds the changer will
cycle to the next available position.
3. Repeat Step 2 until all CDs are loaded in to all of the
desired positions. If you do not wish to load all of
the positions, you can cancel the load all function by
pressing a button with a green flashing indicator
light or wait 20 seconds for the changer to time out.
To eject a single CD perform the following steps:
1. Press the eject button. The buttons with loaded CDs
will blink amber.
2. Press one of the amber blinking buttons to select the
location of the CD you want to eject. The changer
will move to that location and eject the CD. If you
do not remove the CD from the player within ten
seconds, it will be reloaded. If the eject button is
pressed and a numbered location button is not
pressed within five seconds, the current or last
played CD will be ejected.To eject all CDs perform the following step:
Press and hold the eject button.
There are two ways to play a CD. Perform one of
the following steps:
1. Press the desired numbered button with a green
indicator light.
2. Press the CD TAPE button on the radio. The
CD changer will go to its last played position.
PREV (1): Press this button or the SEEK left arrow to
go to the previous track if the current selection has been
playing for less than eight seconds. If the PREV button
is pressed and the current selection has been playing for
more than eight seconds, it will go to the beginning of
the current selection. If you hold or press this button
more than once, the player will continue moving back
through the CD. The sound will mute while seeking.
PROG (2): Press this button to select a CD.
The CD number and track number will be displayed.
NEXT (3): Press this button or the SEEK right arrow
to go to the next track. If you hold the button or press
it more than once, the player will continue moving
forward through the CD. The sound will mute
while seeking.