lock GMC SIERRA 2001 Workshop Manual

3-3 Heater and Air Conditioning Comfort
Controls (If Equipped)
Fan Knob
The knob on the left side of the control panel adjusts the
fan speed. To increase airflow, turn the knob clockwise.
To decrease airflow, turn it counterclockwise. To turn
the fan off, turn the knob to OFF.
Temperature Knob
The middle knob on the control panel lets you select the
temperature of the air flowing into the passenger area.
Turn the knob clockwise toward the red area for warmer
air. Turn the knob counterclockwise toward the blue area
for cooler air.Mode Knob
The right knob on the control panel allows you to
choose the direction of air delivery.
PANEL: This setting directs the air through the
instrument panel outlets and the center floor console
(if equipped).
BI-LEVEL: Air is delivered through the
instrument panel outlets and center floor console outlets
(if equipped) as well as the heater floor outlets. The air
flow can be divided between PANEL and HEATER
depending upon where the knob is placed between the
settings. Pressing the A/C button while in this mode
causes cooler air to come out of the instrument panel
outlets and center floor console outlets (if equipped)
and warmer air to come out of the heater floor outlets.
HEATER: This setting directs most of the
warmed air through the heater floor outlets and center
floor console outlets (if equipped), as well as some
air through the windshield defroster outlets and side
window defroster outlets. If air from the center floor
console outlets is not desired, turn the vents off at
the console.

3-5
The auto recirculation feature will activate when the
following are true:

the air conditioning system is activated,

the OUTSIDE AIR button is on, and

the vehicle load is high due to city traffic,
extended idling or hot weather.
The system will automatically switch to the recirculation
mode to lower the system load and improve interior
comfort. The OUTSIDE AIR and RECIRCULATION
button LEDs will not change. The system will return
to the OUTSIDE AIR function when the system load
is reduced.
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.
Air conditioning will be automatically disabled when
the outside temperature drops below a level at which
air conditioning is ineffective.
Electronic Climate Control System
(If Equipped)
Fan Control
The knob on the left side of the electronic climate control
panel operates the fan speed. To manually increase
airflow, move the knob clockwise. To manually decrease
airflow, move it counterclockwise.
OFF: If the knob is in OFF, outside air will still enter
the vehicle, and will be directed based on the position of
the mode knob.

3-6
AUTO: If the knob is in AUTO, the fan speed will vary
as the system maintains the selected temperature.
When both the fan control and mode knobs are in the
AUTO position, the system will then automatically
maintain the desired cabin temperature as selected by
the temperature knob. Manual control of functions is
also available.
Temperature Knob
The middle knob on the control panel lets you select
the desired air temperature in your vehicle. This knob
will allow you to adjust the interior air temperature
independent of the function knob setting. Move the
knob clockwise toward 82 for warmer air. Move the knob
counterclockwise toward 66 for cooler air. When the
system is set for automatic operation, sensors will control
the fan/blower speed.
Full Hot: If you turn the temperature knob past 82
F
(28
C), the system will go into the ªfull hotº mode.
The system will remain at that maximum heating setting
and the fan will blow at the speed the fan knob is set to.
If the fan is in AUTO, it will run at full speed.
Full Cold: If you turn the temperature knob past 66
F
(19
C), the system will go into the ªfull coldº mode.
The system will remain at that maximum cooling setting
and the fan will blow at the speed the fan knob is set to.
If the fan is in AUTO, it will run at full speed.
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 for automatic operation, 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.

3-10
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 speed of the airflow.
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 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 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
knob to REAR.

3-11 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 knob located on
the left side of the control panel to the desired fan speed.
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 knob can be set to
any blend setting.
For rear control operation, use the above instructions.

3-12 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.

3-16
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.

3-18 AM-FM Stereo with Cassette Tape Player
(If Equipped)
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 this 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, FM1 and FM2.
TUNE: Turn the lower knob to tune in radio stations.
SEEK: Press the right arrow to tune to the next
higher station and the left arrow to tune to the next
lower station.
PUSHBUTTONS: The four numbered pushbuttons
let you return to your favorite stations. You can set up to
21 stations (seven AM, seven FM1 and seven FM2). 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.

3-20
EJECT: Press this button to remove the tape or stop
the tape and play the radio.
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, use the following steps:
1. Turn the radio on.
2. Insert the adapter into the cassette slot.
3. Within five seconds, press and hold the REV and FWD
buttons at the same time for three seconds. The tape
symbol on the display will flash, showing that the
broken tape detection feature is no longer active.
This override routine will remain active until EJECT
is pressed.
AM-FM Stereo with Cassette Tape 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 the knob clockwise.
Turn it counterclockwise to decrease volume. The knob
is capable of being turned 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.

3-21
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.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.