1999 GMC ENVOY light

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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 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.
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 the floor outlets. As the
interior temperature approaches the desired setting, theblower 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 blower 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.
If your vehicle is sitting out on a warm day and you
have the fan set on AUTO, the air will first flow out of
the floor air outlets for a few seconds. That is normal.
This is to expel hot air from the air outlets. As the air is
cooled, the airflow will move through the air
conditioning outlets.
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.
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3-4
Mode Knob - Manual Operation
The right knob on the control panel allows you to
choose the direction of air delivery.
You can choose to set the climate control system
operations yourself, or let the system work for you by
placing the system in AUTO mode. See ªMode
Knob
- Automatic Operationº earlier in this section.
PANEL: This setting directs most of the air
through the instrument panel outlets and a small amount
through the floor outlets.
BI-LEVEL: Air is delivered through the heater
floor outlets as well as the instrument panel outlets.
HEATER: This setting directs most of the
warmed air through the heater floor outlets and some air
through the windshield defroster outlets.
BLEND: Airflow is divided equally between the
heater floor outlet and the windshield defroster outlets.
The air conditioning compressor may run to dehumidify
the air to prevent window fogging.
DEFROST: This setting directs most air through
the windshield defroster outlets and some through the
heater outlets. The air conditioning compressor may run
to dehumidify the air to prevent window fogging.
OUTSIDE AIR: Press this button to force the
system to use outside air. Press it again to close off the
outside air.
Pressing the OUTSIDE AIR button will cancel the
RECIRCULATION button.
RECIRCULATION: Press this button to limit the
amount of fresh air entering your vehicle. This is helpful
when you are trying to limit odors entering your vehicle. In
the AUTO mode, the system will use recirculation as
necessary to cool the air. Pressing the recirculation button
will change the operation to a manual mode and the air will
recirculate non
-stop.
RECIRCULATION may be selected with the fan control
in OFF to limit odors, outside air and dust from entering
your vehicle.
Pressing the RECIRCULATION button will cancel the
OUTSIDE AIR button.
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 which air
conditioning is ineffective.
Remember that in order for the automatic system to perform
well, it needs A/C to provide cooling performance.
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3-5 Air Conditioning
On hot days, open the windows long enough to let hot
inside air 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.
For quick cool
-down on very hot days, the A/C button
should be enabled and the OUTSIDE AIR button should
not be active.
On cool but sunny days, use BI
-LEVEL A/C to deliver
warm air to the floor and cooler air to the instrument
panel outlets.
When the air conditioner is on, you may sometimes
notice slight changes in your vehicle's engine speed and
power. This is normal because the system is designed to
cycle the compressor on and off to keep the
desired temperature.
Heating
The heater works best if you keep your windows closed
while using it. On cold days, use HEATER with the
temperature knob turned toward the red area. BLEND is
useful in cool weather when you have fog or ice on the
windshield or side windows.
If you use the optional engine coolant heater before
starting your engine, your heating system will produce
warmer air faster to heat the passenger compartment in
cold weather. See ªEngine Coolant Heaterº in the Index.
Defogging and Defrosting
On cool, humid days, use BLEND to keep the
windshield and side windows clear.
Use DEFROST to remove fog or ice from the
windshield quickly in extreme humid or cold conditions.
Turn the temperature knob toward the red area and
move the fan control toward the red area.
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3-6 Rear Window Defogger
The lines you see on
the rear window warm
the glass.
For best results, clear the window of as much snow or
ice as possible before using the rear window defogger.
To turn on the rear window defogger, find the button
marked REAR with the defog symbol on the lower right
corner of your climate control system. Press the button
until the light in the switch comes on, then release it. It
will only work if the ignition switch is turned to RUN.Pressing the REAR button on your climate control
system will also activate your heated outside mirrors.
This will help to keep ice, snow and condensation from
collecting on your mirror surfaces.
The rear window defogger will stay on for five to seven
minutes, then turn off. If you need additional warming
time, turn it on again. You can turn the defogger off at
any time by pressing the button.
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.
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3-9
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.
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 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.
5. Repeat the steps for each pushbutton.
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3-10
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.
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.
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.
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3-11
The player automatically senses if the cassette tape is metal
or CrO
2 and adjusts for best playback sound. For metal tapes,
the double
-D symbol will appear on the display.
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.
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 to
the radio.
TAPE AUX: 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 TAPE AUX to switch between the
tape player and console
-mounted CD changer if both 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.
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3-13
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.
REAR DSPL: When the primary radio is turned on,
press this button to turn the rear seat audio display on
the primary radio on. 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.
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.
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