lock GMC YUKON XL 2002 Repair Manual

3-9Defogging 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 knob turned all the
way clockwise.
Rear Window Defogger The lines running across the rear window are the
defogger grid. The lines warm the glass.
To turn on the rear
window defogger, press this
button located below the
mode 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.
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.
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.

3-11Ventilation 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 non
- GM approved 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 of 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 turned 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.

3-12AM-FM Stereo with Cassette
Tape Player (Bose

)
Included with this audio system are ten Bose

speakers,
an Acoustimass

bass module and a seven channel Bose
amplifier. See your dealer for details.
Playing the Radio
PWR (Power): Press this knob to turn the system on
and off.
VOL (Volume): Turn this knob clockwise to increase
volume. Turn it counterclockwise to decrease volume.
The knob is capable of being turned continuously. REAR DSPL (Display): When the main radio is turned
on, press this button to see the rear seat audio settings
displayed on the main radio. Press it again to turn the
rear seat audio display off. See ªRear Seat Audioº in the
Index for more information.
RECALL: Press this button to display the station being
played or to display the clock. Clock display is available
with the ignition turned off.
SCV (Speed
- Compensated Volume): 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. Each notch on the
control ring allows for more volume compensation at
faster vehicle speeds. Then, as you drive, SCV
automatically increases the volume, as necessary, to
overcome noise at any 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 ring counterclockwise.

3-14 Setting the Tone (Bass/Treble)
BASS: Press this knob lightly so it extends. Turn the
knob clockwise to increase bass and counterclockwise to
decrease bass.
TREB (Treble): Press this knob lightly so it extends.
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 (Balance/Fade)
BAL (Balance): Press this knob lightly so it extends.
Turn the knob 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.
FADE: Press this knob lightly so it extends. Turn the
knob 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.
If an error appears on the display, see ªCassette Tape
Messagesº later in this section.
1 PREV (Previous): Press this pushbutton or the left
SEEK 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 while in previous mode.

3-17Rear Seat Audio Controls
The following functions are controlled by the RSA
system buttons:
PWR (Power): Press this button to turn the rear seat
audio system on or off. The rear speakers will be muted
when the power is turned on. You will hear your source
through headphones. You may operate the rear seat
audio functions even when the primary radio power
is off. VOL (Volume): 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 knob controls the headphone plugged into the
upper jack and the lower knob controls the headphone
plugged into the lower jack.
AM FM: Press this button to switch between AM, FM1
and FM2. If the front passengers are already listening to
AM FM, the RSA controller will not switch between the
bands and cannot change the frequency.
Press AM FM to return to listening to the radio when a
cassette tape or CD is playing. The inactive tape or CD
will remain safely inside the radio for future listening.

3-22Theft-Deterrent Feature 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 pushbuttons at the same time. 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 knob will begin
flashing when the ignition is turned off.

3-23Unlocking 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 pushbuttons at the same time. 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.

4-7Avoid 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 Brake System (ABS) Your vehicle has anti
- lock brakes. 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 Let's say the road is wet and 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.

4-9Remember: 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.