lock GMC YUKON XL DENALI 2001 Repair Manual

3-11
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.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.
Your vehicle has a feature called Retained Accessory
Power (RAP). With RAP, you can play your audio
system even after the ignition is off. See ªRetained
Accessory Powerº in the Index.
Setting the Clock
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.

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.

3-16 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.

3-21 Theft-Deterrent Feature (If Equipped)
THEFTLOCK
is designed to discourage theft of your
radio. It works by using a secret code to disable all radio
functions whenever battery power is removed.
The THEFTLOCK feature for the radio may be used or
ignored. If ignored, the system plays normally and the
radio is not protected by the feature. If THEFTLOCK
is activated, your radio will not operate if stolen.
When THEFTLOCK is activated, the radio will display
LOC to indicate a locked condition anytime battery
power has been interrupted. If your battery loses power
for any reason, you must unlock the radio with the secret
code before it will operate.
Activating the Theft
-Deterrent Feature
The instructions which follow explain how to enter your
secret code to activate the THEFTLOCK system. It is
recommended that you read through all nine steps
before starting the procedure.
If you allow more than 15 seconds to elapse between
any steps, the radio automatically reverts to time and
you must start the procedure over at Step 4.1. Write down any three or four
-digit number from
000 to 1999 and keep it in a safe place separate from
the vehicle.
2. Turn the ignition to ACCESSORY or RUN.
3. Turn the radio off.
4. Press the 1 and 4 buttons together. Hold them down
until
--- shows on the display. Next you will use the
secret code number which you have written down.
5. Press MN and 000 will appear on the display.
6. Press MN again to make the last two digits agree
with your code.
7. Press HR to make the first one or two digits agree
with your code.
8. Press AM
-FM after you have confirmed that the
code matches the secret code you have written down.
The display will show REP to let you know that you
need to repeat Steps 5 through 7 to confirm your
secret code.
9. Press AM
-FM and this time the display will show
SEC to let you know that your radio is secure. The
LED indicator by the volume control will begin
flashing when the ignition is turned off.

3-22
Unlocking the Theft-Deterrent Feature After a
Power Loss
Enter your secret code as follows; pause no more than
15 seconds between steps:
1. Turn the ignition on. LOC will appear on the display.
2. Press MN and 000 will appear on the display.
3. Press MN again to make the last two digits agree
with your code.
4. Press HR to make the first one or two digits agree
with your code.
5. Press AM
-FM after you have confirmed that the
code matches the secret code you have written down.
The display will show SEC, indicating the radio is
now operable and secure.
If you enter the wrong code eight times, INOP will
appear on the display. You will have to wait an hour
with the ignition on before you can try again. When you
try again, you will only have three chances to enter the
correct code before INOP appears.
If you lose or forget your code, contact your dealer.Disabling the Theft
-Deterrent Feature
Enter your secret code as follows; pause no more than
15 seconds between steps:
1. Turn the ignition to ACCESSORY or RUN.
2. Turn the radio off.
3. Press the 1 and 4 buttons together. Hold them down
until SEC shows on the display.
4. Press MN and 000 will appear on the display.
5. Press MN again to make the last two digits agree
with your code.
6. Press HR to make the first one or two digits agree
with your code.
7. Press AM
-FM after you have confirmed that the
code matches the secret code you have written down.
The display will show
---, indicating that the radio
is no longer secured.
If the code entered is incorrect, SEC will appear on the
display. The radio will remain secured until the correct
code is entered.
When battery power is removed and later applied to a
secured radio, the radio won't turn on and LOC will
appear on the display.
To unlock a secured radio, see ªUnlocking the
Theft
-Deterrent Feature After a Power Lossº earlier
in this section.

4-7
Avoid needless heavy braking. Some people drive in
spurts
-- heavy acceleration followed by heavy
braking
-- rather than keeping pace with traffic.
This is a mistake. Your brakes may not have time to
cool between hard stops. Your brakes will wear out
much faster if you do a lot of heavy braking. If you
keep pace with the traffic and allow realistic following
distances, you will eliminate a lot of unnecessary
braking. That means better braking and longer
brake life.
If your engine ever stops while you're driving, brake
normally but don't pump your brakes. If you do,
the pedal may get harder to push down. If your engine
stops, you will still have some power brake assist.
But you will use it when you brake. Once the power
assist is used up, it may take longer to stop and the
brake pedal will be harder to push.
Anti-Lock Brakes (ABS)
Your vehicle has anti-lock brakes (ABS). ABS is an
advanced electronic braking system that will help
prevent a braking skid.
When you start your engine and begin to drive away,
your anti
-lock brake system will check itself. You may
hear a momentary motor or clicking noise while this test
is going on. This is normal.
If there's a problem with the
anti
-lock brake system, this
warning light will stay on.
See ªAnti
-Lock Brake
System Warning Lightº in
the Index.

4-8
Here's how anti-lock works. Let's say the road is wet.
You're driving safely. Suddenly an animal jumps out in
front of you.
You slam on the brakes and continue braking. Here's
what happens with ABS.
A computer senses that wheels are slowing down. If one
of the wheels is about to stop rolling, the computer will
separately work the brakes at each front wheel and at
both rear wheels.The anti
-lock system can change the brake pressure
faster than any driver could. The computer is
programmed to make the most of available tire and road
conditions. This can help you steer around the obstacle
while braking hard.
As you brake, your computer keeps receiving updates on
wheel speed and controls braking pressure accordingly.

4-9
Remember: Anti-lock doesn't change the time you need
to get your foot up to the brake pedal or always decrease
stopping distance. If you get too close to the vehicle in
front of you, you won't have time to apply your brakes
if that vehicle suddenly slows or stops. Always leave
enough room up ahead to stop, even though you have
anti
-lock brakes.
Using Anti
-Lock
Don't pump the brakes. Just hold the brake pedal down
firmly and let anti
-lock work for you. You may feel the
brakes vibrate, or you may notice some noise, but this
is normal.
Braking in Emergencies
With anti-lock, you can steer and brake at the same
time. In many emergencies, steering can help you more
than even the very best braking.
Steering
Power Steering
If you lose power steering assist because the engine
stops or the system is not functioning, you can steer
but it will take much more effort.
Speed-Sensitive Steering
This system varies the amount of steering effort
proportionate to your vehicle speed. Steering is easier
at lower speeds for maneuvering and parking ease.
As your vehicle speed increases, the steering effort
also increases. At highway speeds, the amount of
steering effort is increased.
Steering Tips
Driving on Curves
It's important to take curves at a reasonable speed.
A lot of the ªdriver lost controlº accidents mentioned
on the news happen on curves. Here's why:
Experienced driver or beginner, each of us is subject to
the same laws of physics when driving on curves. The
traction of the tires against the road surface makes it
possible for the vehicle to change its path when you turn
the front wheels. If there's no traction, inertia will keep
the vehicle going in the same direction. If you've ever
tried to steer a vehicle on wet ice, you'll understand this.
The traction you can get in a curve depends on the
condition of your tires and the road surface, the angle
at which the curve is banked, and your speed.
While you're in a curve, speed is the one factor you
can control.