lock GMC SIERRA 2001 Repair Manual

3-22
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
-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. When the BASS
control is turned, the AUTO TONE display will go blank.
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. When the
TREB control is turned, the AUTO TONE display will
go blank. 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.AUTO TONE: Press this button to select among the
six preset equalization settings and tailor the sound to
the music or voice being heard. Each time you press the
button, the selection will switch to one of the preset
settings of CLASSIC, NEWS, ROCK, POP, C/W
(Country/Western) or JAZZ. To return to the manual
mode, press and release this button until the AUTO
TONE display goes blank. This will return the tone
adjustment to the BASS and TREB controls. If a
BASS or TREB control is turned, the AUTO TONE
display will go blank. Use PUSHBUTTONS to program
AUTO TONE.
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.
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.

3-25 AM-FM Stereo with Compact Disc Player
and Automatic Tone Control (If Equipped)
Playing the Radio
PWR
-VOL: Press this knob to turn the system on
and off. To increase volume, turn this knob clockwise.
Turn it counterclockwise to decrease volume. The knob
is capable of rotating continuously.
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.

3-26
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). Just:
1. Turn the radio on.
2. Press AM
-FM to select the band.
3. Tune in the desired station.
4. Press AUTO TONE to select the setting
you prefer.
5. Press and hold one of the six pushbuttons.
The sound will mute. When it returns, release
the button. Whenever you press that numbered
button, the station you set will return and the
tone you selected will be automatically selected
for that button.
6. 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 stored 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-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. When the BASS
control is turned, the AUTO TONE display will go blank.
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. When the
TREB control is turned, the AUTO TONE display will
go blank. 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.

3-27
AUTO TONE: Press this button to select among the
six preset equalization settings and tailor the sound to
the music or voice being heard. Each time you press the
button, the selection will switch to one of the preset
settings of CLASSIC, NEWS, ROCK, POP, C/W
(Country/Western) or JAZZ. To return to the manual
mode, press and release this button until the AUTO
TONE display goes blank. This will return the tone
adjustment to the BASS and TREB controls. If a
BASS or TREB control is turned, the AUTO TONE
display will go blank. Use PUSHBUTTONS to program
AUTO TONE.
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.
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 Compact Disc
PWR: Press this knob to turn the system on.
(You can also turn the system on when you insert a
compact disc into the player with the ignition on.)
Insert a disc partway into the slot, label side up.
The player will pull it in. Wait a few seconds and the
disc should play. CD and a CD symbol will also
appear on the display. Anytime you are playing a CD,
the letters CD will be next to the CD symbol.
If the disc comes back out and ERR appears on the
display, it could be that:

You are driving on a very rough road. (The disc
should play when the road gets smoother.)

The disc is upside down.

It is dirty, scratched or wet.

It is very humid. (If so, wait about an hour
and try again.)

The disc player is very hot.
Press RECALL to make ERR go off the display.

3-30
(5): Press this pushbutton to turn Dolby NR on and off.
Dolby NR is active when a tape is inserted in the remote
cassette. The double
-D symbol will appear on the display.
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.
FWD (6): Press this button to rapidly advance the tape.
The tape will rapidly advance to the end of the cassette
reel or until you press FWD again. The radio plays the
last selected station during FWD.
PROG: Press this button on the remote player to go
from one side of the tape to the other.
TAPE: Press the AM
-FM button to switch from the
player and the radio when a tape is playing. To return to
the tape player, press CD AUX. The lighted arrow will
appear next to the symbol and show the direction of play
when a tape is active.
EJECT: Press this button on the remote player to
remove the tape. EJECT can be used with either the
ignition or radio off. Also, you must press EJECT before
loading a cassette with the radio off to allow loading.
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.

3-31
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.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.

3-32
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.
Understanding Radio Reception
AM
The range for most AM stations is greater than for FM,
especially at night. The longer range, however, can
cause stations to interfere with each other. AM can pick
up noise from things like storms and power lines. Try
reducing the treble to reduce this noise if you ever get it.
FM Stereo
FM stereo will give you the best sound, but FM signals
will reach only about 10 to 40 miles (16 to 65 km). Tall
buildings or hills can interfere with FM signals, causing
the sound to come and go.

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.
Traction Assist System (Option)
Your vehicle may have a Traction Assist System (TAS)
that limits wheel spin. This is especially useful in
slippery road conditions. The system operates only if it
senses that one or both of the rear wheels are spinning
or beginning to lose traction. When this happens, the
system reduces engine power to limit wheel spin.
This light will come
on when the TAS is
limiting wheel spin.
See ªLow Traction Lightº
in the Index.
You may hear or feel the system working or notice a
lack of accelerator response, but this is normal.