GMC chevrolet camaro 2000 Service Manual page 243

1-146 HVAC Systems - Manual
Temperature Control Knob
The temperature control knob regulates the HVAC
system air temperature. The knob is located in
the center of the HVAC control head. A temperature
control cable mechanically links the knob to the
temperature valve (door).
• Turn the knob toward the driver for heat.
" Turn the knob toward the passenger for air
conditioning (A/C).
Mode Control Knob
The mode control knob is located on the right side of
the HVAC control head. The following are the
eight different modes:
• OFF
• MAX
"A/C
.. Bl-LEVEL A/C
.. VENT
• HEATER
" DEFROST/BLEND
• DEFROST
OFF
The following actions occur when the knob is in the
OFF position:
• The blower motor does not operate.
• Electrical power is not supplied to the
blower motor.
" An A/C request signal is not sent to the powertrain
control module (PCM).
• A small amount of air is forced into the HVAC
module by the forward movement of the vehicle.
The air is discharged through the heater and
defrost outlets.
MAX
The following actions occur when the knob is in the
MAX position:
• An A/C request signal is sent to the PCM.
• The blower motor operates in one of four blower
motor speed control settings.
• Air is discharged only from the instrument panel
air outlets.
• In order to provide MAX A/C, most of the air
entering the HV AC module is taken from the
vehicle interior (re-circulated). This interior air is
cooler than the outside air. MAX is the only setting
at which the air is re-circulated.
Use the MAX setting when the following
conditions exist:
• High temperature
.. High humidity
• The outside air has an objectionable odor
A/C
The A/C setting functions the same as the MAX
setting, except that only outside air enters the HVAC
module. There may be a slight reduction of blower
noise compared to the MAX setting because the
re-circulation valve (door) is closed.
HVAC
Bl-LEVEL A/C
The following actions occur when the knob is in the
Bl-LEVEL A/C position:
• An A/C request signal is sent to the PCM in order
to allow the blower motor to operate in one of
four settings.
O
Only outside air enters the HVAC module.
• Air is distributed through the instrument panel
outlets arid the floor outlets.
• A small amount of air is distributed to the defrost
outlet.
VENT
The VENT setting does not activate an A/C request
signal but allows the blower motor to operate normally.
The VENT setting is one of two economy settings
(other than OFF) in which there is no A/C request
signal. Air is discharged through the instrument panel
outlets only .
HEATER
The HEATER setting functions the same as the VENT
setting, except that most of the air is discharged
through the floor outlets with a small amount of air
discharged through the defroster outlets. Use
the HEATER setting for cold weather operation unless
windshield or side window defogging/defrosting is
required.
DEFROST/BLEND
The following actions occur in the DEFROST/BLEND
setting:
• The blower motor operates.
• An A/C request signal is sent to the PCM.
• Air is discharged through the defroster and floor
air outlets.
The DEFROST/BLEND setting provides greater
passenger comfort :than the DEFROST setting, but it
is not as effective in defogging/defrosting the
windshield and side windows.
DEFROST
The DEFROST setting functions the same as the
DEFROST/BLEND setting except that most of the air
is discharged through the defroster outlets. A small
amount of air goes through the heater and side
windows defoggers.
Blower Motor Speed Control
• The blower motor runs in all mode positions
except the OFF position when the ignition switch
is in the RUN position.
• The blower motor speed is controlled by a
four-position electrical blower motor speed control
switch. The switch is located at the left side of
the control.
• The blower motor speed control switch provides a
choice of the following speeds:
O
Low
0
Medium (two settings)
• High
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