2005 CHRYSLER CARAVAN heater

a combination of the three main housing outlets:
defrost, panel or floor. The defrost and panel outlets
are located on the top of the housing and the floor
outlet is located on the bottom of the housing. Once
the conditioned air exits the unit housing, it is fur-
ther directed through molded plastic ducts to the var-
ious outlets in the vehicle interior. These outlets and
their locations are as follows:
²Defroster Outlet- A single large defroster out-
let is located in the center of the instrument panel
top cover, near the base of the windshield.
²Side Window Demister Outlets- There are
two side window demister outlets, one is located at
each outboard end of the instrument panel, near the
A-pillars.
²Panel Outlets- There are five panel outlets in
the instrument panel, one located near each outboard
end of the instrument panel facing the rear of the
vehicle and three located near the top of the instru-
ment panel center bezel.
²Front Floor Outlets- There are two front floor
outlets, one located above each side of the center of
the floor panel near the dash panel.
MANUAL SINGLE ZONE
The manual single zone heating and A/C system
allows one temperature setting for the entire vehicle.
The full range of temperatures that the system can
produce are available by rotating the temperature
control located on the A/C-heater control.
The A/C-heater control and integral computer is
located in the instrument panel and contains:
²a rear window defogger on/off switch. Contains
an LED that illuminates to show when the function
is operational.
²an air recirculation on/off switch. The Recircu-
late button contains an LED that illuminates to show
when the function is in operation.
²an air conditioning on/off switch. The Snowflake
button contains an LED that illuminates to shown
when the function is in operation.
²a rotary knob for fan speed selection and turn-
ing the heater-A/C system off.
²a rotary knob for temperature control of the dis-
charged air.
²a rotary knob for mode control.
MANUAL DUAL ZONE
The manual dual zone heating and A/C system
allows completely independent side-to-side tempera-
ture control of the discharge air.
The A/C-heater control and integral computer is
located in the instrument panel and contains:
²a rear window defogger on/off switch. Contains
an LED that illuminates to show when the function
is operational.²slide controls for completely independent side-to-
side temperature control of the discharged air. The
full range of temperature that the system can pro-
duce in any mode is available on either side of the
vehicle by independently positioning the slide con-
trols on the instrument panel.
²an air recirculation on/off switch. The Recircu-
late button contains an LED that illuminates to show
when the function is in operation.
²an air conditioning on/off switch. The Snowflake
button contains an LED that illuminates to shown
when the function is in operation.
²a rotary knob for fan speed selection and turn-
ing the heater-A/C system off.
²a rotary knob for mode control.
MANUAL THREE ZONE
The fully adjustable manual three zone front and
rear heating and A/C system allows intermediate
seat passengers the ability to regulate air tempera-
ture as well as fan speed and provides floor outlets to
the rear of the right sliding door and overhead out-
lets at each rear outboard seating position. Primary
control for the rear blower is on the front A/C-heater
control. All controls are identified by ISO graphic
symbols.
FRONT CONTROL PANEL
The front A/C-heater control and integral computer
mounted in the instrument panel contains:
²a rear window defogger on/off switch.
²slide controls for completely independent side-to-
side temperature control of the discharge air. The full
range of temperature that the system can produce in
any mode is available on either side of the vehicle by
independently positioning the slide controls on the
instrument panel.
²an air recirculation button. The Recirculate but-
ton contains an LED that illuminates to show when
the function is in operation.
²an air conditioning button that allows the com-
pressor to be turned on/off. The Snowflake button
contains an LED that illuminates to shown when the
function is in operation.
²a rotary knob for front fan speed selection and
turning the heater-A/C system off.
²a rotary knob for rear fan speed selection.
²a rotary knob for mode control.
REAR CONTROL PANEL
The rear A/C-heater control centrally mounted in
the headliner allows intermediate seat passengers to
adjust rear air distribution, temperature and blower
motor speed when the center knob on the front A/C-
heater control is set to the Rear position. The rear
A/C-heater control contains:
24 - 2 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

²a rotary adjustment knob for temperature.
²a rotary adjustment for fan speed control.
AUTOMATIC TEMPERATURE CONTROL
Two different automatic temperature control (ATC)
heating-A/C systems are available for this model
depending on the market.
The Dual-Zone ATC system allows the driver and
front occupants to each select individual comfort tem-
peratures.
The Three-Zone ATC system allows both the driver
and front occupants and the rear intermediate occu-
pants to select individual comfort temperatures.
NOTE: Individual comfort temperatures are the per-
ceived temperature level at the individual seating
areas, NOT the actual passenger compartment air
temperature.
The ATC system includes a particulate air filter.
The filter element is the same size as the A/C evap-
orator to ensure ample capacity. A door at the base of
the HVAC housing below the glove box provides easy
access to the filter element.
The ATC computer utilizes integrated circuitry and
information carried on the programmable communi-
cations interface (PCI) data bus network to monitor
many sensors and switch inputs throughout the vehi-
cle. In response to those inputs, the internal circuitry
and programming of the ATC computer allow it to
control electronic functions and features of the ATC
system. The inputs to the ATC computer are:
²Vehicle Speed/Engine RPM± The ATC com-
puter monitors engine rpm, vehicle speed and mani-
fold absolute pressure information from the
powertrain control module (PCM).
²Coolant Temperature± ATC computer moni-
tors coolant temperature received from the PCM and
converts it to degrees Fahrenheit.
²Ambient Temperature± ATC computer moni-
tors ambient temperature from the compass mini trip
computer (CMTC) and converts it to degrees Fahren-
heit.
²Engine Miscellaneous Sensor Status±ATC
computer monitors A/C disable information from the
PCM.
²Refrigerant Pressure± ATC computer moni-
tors barometric pressure, intake air temperature,
high side pressure and methanol content as broad-
cast by the PCM.
²Door Ajar Status± The ATC computer moni-
tors driver front door, passenger front door, left rear
door, right rear door and liftgate ajar information, as
identified by the body control module (BCM), to
determine if all in-car temperatures should be main-
tained.²Dimming± The ATC computer monitors dim-
ming status from the BCM to determine the required
level of brightness and will dim accordingly.
²Vehicle Odometer± The ATC computer moni-
tors the vehicle odometer information from the BCM
to prevent flashing the vacuum-flourescent (VF) dig-
ital display icons if the manual motor calibration or
manual cool down tests have failed. Flashing of the
display icons will cease when the vehicle odometer is
greater than 3 miles.
²English/Metric± The ATC computer monitors
the English/Metric information broadcast by the
CMTC. The set temp displays for both the front and
rear control heads will be set accordingly.
²Vehicle Identification Number± The ATC
computer monitors the last eight characters of the
VIN broadcast by the PCM and compares it to the
information stored in EEPROM. If it is different, the
new number will be stored over the old one and a
motor calibration shall be initiated.
²A/C System Information± The ATC computer
will send a message for evaporator temperature too
low, fan blower relay status, evaporator sensor fail-
ure, rear window defogger relay and A/C select.
FRONT CONTROL PANEL
The front A/C-heater control and integral computer
is mounted in the instrument panel and contains:
²a power button which allows the system to be
completely turned off. The display is blank when the
system is off.
²a rocker switch that selects a cool-down rate.
LO-AUTO or HI-AUTO are displayed when the sys-
tem is in automatic operation.
²three rocker switches that select comfort temper-
atures from 15É to 30É C (59É to 85É F), which are
shown in the VF digital display. If the set temp is 15É
C (59É F) and the down button is pressed, the set
temp value will become 13É C (55É F) but the display
will show LO. If the set temp is 29É C (85É F) and the
up button is pressed, the set temp value will become
32É C (90É F) but the display will show HIGH. Tem-
peratures can be displayed in either metric or Fahr-
enheit, which is controlled from the overhead console.
²an air conditioning button that allows the com-
pressor to be turned off. A Snowflake symbol is illu-
minated when air conditioning is on, whether under
manual or automatic control.
²an air recirculation button. A Recirculation sym-
bol appears in the display when the button is
pressed, or when the system exceeds 80 percent recir-
culated air under automatic control due to high air
conditioning demand.
²a rear window defogger on/off switch. A graphic
symbol shows when the defroster is on.
RSHEATING & AIR CONDITIONING24-3
HEATING & AIR CONDITIONING (Continued)

²a rotary knob for front fan speed selection can
override the automatic controls. LEDs surrounding
the knob show the current setting.
²a rotary knob for control of the rear system
(Three-Zone ATC system only).
²a rotary knob for mode control can override the
automatic controls. LEDs surrounding the knob show
the current setting.
²computer logic which remembers the settings of
the controls when the ignition is turned off and
retains those settings after a restart. If the system is
off when the ignition is turned off it will be off when
the engine is restarted, etc.
²computer logic which provides variable air recir-
culation under high temperature and humidity condi-
tions. Because recirculation is generally accompanied
by increased fan noise, the proportion of recirculated
to outside air gradually approaches full recirculation
over a broad temperature range.
²computer logic which enables additional heat for
diesel equipped vehicles by using a supplemental
engine coolant heater.
REAR CONTROL PANEL
The Three-Zone ATC sytem utilizes a rear control
panel centrally mounted on the headliner which
includes a VF digital display, a rocker control for
temperature and rotary controls for adjustment of
mode and fan speed of the rear heating-A/C system
by intermediate seat passengers.
OPERATION
HEATER AND AIR CONDITIONER
The heating and air conditioning systems pulls
outside (ambient) air through the cowl opening at the
base of the windshield and into the plenum chamber
above the heating, ventilation and air conditioning
(HVAC) housing, then through the evaporator coil.
Air flow can be directed either through or around the
heater core by adjusting the blend door with the tem-
perature control knob on the A/C-heater control
located on instrument panel. The air flow can then
be directed out from the panel, floor and defrost out-
lets in various combinations using the mode control
knob located on the A/C-heater control. Air flow
velocity can be adjusted with the blower speed selec-
tor located on the A/C-heater control.
NOTE: It is important to keep the air intake opening
clear of debris. Leaf particles and other debris that
is small enough to pass through the cowl opening
screen can accumulate within the HVAC housing.
The closed, warm, damp and dark environment cre-
ated within the housing is ideal for the growth of
certain molds, mildews and other fungi. Any accu-mulation of decaying plant matter provides an addi-
tional food source for fungal spores, which enter
the housing with the fresh intake-air. Excess debris,
as well as objectionable odors created by decaying
plant matter and growing fungi can be discharged
into the passenger compartment during heater-A/C
operation if the air intake opening is not kept clear
of debris.
The heater and air conditioning system is a blend-
air type system. In a blend-air system, a blend door
controls the amount of conditioned air that is allowed
to flow through, or around, the heater core. The tem-
perature control knob determines the discharge air
temperature by actuating an electric motor, which
operates the blend door. This allows an almost imme-
diate control of the output air temperature of the sys-
tem.
On all models, the outside air intake can be shut
off by pressing the Recirculation button on the A/C-
heater control. This will operate a electric actuated
recirculation air door that closes off the outside fresh
air intake and recirculates the air that is already
inside the vehicle.
The air conditioning compressor can be engaged in
any mode by pressing the snowflake, A/C on/off but-
ton. It can also be engaged by placing the mode con-
trol in the mix to defrost positions. This will remove
heat and humidity from the air before it is directed
through or around the heater core. The mode control
knob on the A/C-heater control is used to also direct
the conditioned air to the selected system outlets.
The mode control switch uses an electric motor to
control the mode doors.MANUAL SINGLE ZONE
²The temperature control knob enables continu-
ously variable proportioning of the conditioned air.
²The mode control knob enables continuously
variable proportioning of air flow between modes and
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position.
²When the heater-A/C system is off, the HVAC
computer closes the recirculation door to prevent out-
side air from entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the A/C-
heater control.
²To reduce humidity for rapid defogging, the A/C
compressor runs automatically in modes from ªmixº
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off button.
24 - 4 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

MANUAL DUAL ZONE
²The two slide controls enable continuously vari-
able proportioning of the conditioned air.
²The mode control knob enables continuously
variable proportioning of air flow between modes and
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position.
²When the heater-A/C system is off, the HVAC
computer closes the recirculation door to prevent out-
side air from entering the passenger compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the A/C-
heater control.
²To reduce humidity for rapid defogging, the A/C
compressor runs automatically in modes from ªmixº
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off button.
MANUAL THREE ZONE
FRONT CONTROL PANEL
²Primary control of the rear heater-A/C system is
on the instrument panel. This control allows the
driver to set the rear compartment fan speed, to turn
the rear heater-A/C system off, or to give control to
the intermediate seat occupants by switching to the
Rear position. When the rear heater-A/C system is
controlled from the instrument panel, rear air tem-
perature is based on the driver-side temperature con-
trol position, and the mode (floor or overhead air) is
based on the front control's mode position.
²The mode control knob enables continuously
variable proportioning of air flow between modes but
has detents adjacent to each icon.
²The blower control provides four separate speeds
and an Off position. When the heater-A/C system is
off, the HVAC computer closes the recirculation door
to prevent outside air from entering the passenger
compartment.
²Interior air may be recirculated to speed up
heating or cooling in all modes except defrost and
mix by pressing the Recirculate button on the control
panel.
²To reduce humidity for rapid defogging the A/C
compressor runs automatically in modes from ªmix'
to full defrost when outside temperatures are above
freezing.
²Air conditioning is available in any mode by
pressing the snowflake, A/C on/off, button.
REAR CONTROL PANEL
With the rear control active, temperature selection
dictates the air distribution mode (floor or overhead
air) of the rear unit: a cool temperature setting
directs flow to the overhead outlets and a warm tem-
perature setting to the floor.
AUTOMATIC TEMPERATURE CONTROL
Comfort temperature or perceived temperature is
affected by air flow, sun levels on exposed skin, etc.
The air temperature may be higher or lower than the
comfort temperature. The automatic temperature
control (ATC) system uses two infrared sensors in the
instrument panel center stack to measure the tem-
perature of the front occupants in order determine
their comfort level relative to their selected comfort
temperature. The integral HVAC computer adjusts
temperature and air flow rates to maintain the cus-
tomer-perceived comfort temperatures. The air tem-
perature in the passenger compartment may be
slightly higher or lower than the comfort tempera-
ture at any time. For instance, on sunny summer
days the air flow will probably be cooler than the
comfort temperature; on cold or cloudy days and at
night it will probably be slightly warmer.
The Three-Zone ATC system uses the infrared sen-
sors located in the instrument panel center stack
along with an offset calibration strategy to meet the
comfort requirements of the rear seat occupants.
FRONT CONTROL PANEL
²AUTO HI/LO± This system features two sets of
automatic control logic that allow either a rapid cool-
down rate or a somewhat slower cool-down rate with
less fan noise. HI-AUTO controls the system to reach
its assigned temperature quickly with a higher fan
speed. LO-AUTO controls the system to reach its
assigned temperature somewhat slower with less fan
noise. Both modes will automatically engage auto
recirculation.
²DEFROST± The defrost function must be man-
ually selected to direct air flow to the windshield to
remove fog or ice. The ATC system cannot automati-
cally sense the presence of fog or ice on the wind-
shield.
²RECIRC± The RECIRC button will close the
air inlet door. If the system is in auto recirc (indica-
tor being displayed automatically), pressing the man-
ual recirc button will disable the auto recirc function
until one of the auto keys are pressed or the ignition
is cycled. If Auto HI/LO is pressed while manual
recirc is active, manual recirc will be deactivated.
²REAR WINDOW DEFOGGER± Pushing the
button sends a PCI bus message to the intelligent
power module which controls the rear window defog-
ger and side view mirror (if equipped) circuitry. The
RSHEATING & AIR CONDITIONING24-5
HEATING & AIR CONDITIONING (Continued)

defogger function will be active for 10 minutes and
can be turned off by a switch press. The defogger will
function while the control is in the ON mode.
²FAN/MODE± The Fan and Mode knobs have
17 manual selectable positions. Manually changing
either of the rotary knobs for mode or fan speed set-
tings makes control of that blower motor manual. If
only one is changed manually, the other remains
under automatic control. Pressing the HI-AUTO/LO-
AUTO rocker switch restores full automatic control.
²BLOWER DELAY TIMER± The word DELAY
is displayed at start-up to signify that the system is
waiting so that cold air will not be blowing. This tells
the operator that it is unnecessary to turn the sys-
tem off, raise the temperature setting or turn the fan
speed setting down to prevent cold air from blowing.
A countdown in minutes and seconds until the engine
is warm enough to begin delivering heat to the pas-
sengers alternates with the DELAY message at 25
second intervals. This countdown is based on actual
measurement of the rate of engine coolant tempera-
ture change. During the delay time, mix mode is
selected and the fan operates at a low speed to keep
the windshield fog free.
²REAR CONTROL (Three-Zone only)± When
the Rear System control knob is moved to the OFF
position, there will be a delay of approximately 1 sec-
ond before the system actually turns off. This delay
is to prevent an undesired blower dropout if the knob
is moved through OFF to the other selections.
REAR CONTROL PANEL ± THREE ZONE ATC
SYSTEM
Primary control of the rear compartment heating-
A/C system for the Three-Zone ATC system is in the
instrument panel center stack. This control allows
the driver to turn the rear heating-A/C system off, or
allows the intermediate seat occupants control of the
rear system by switching to the REAR position, or
provides fully automatic control based on the temper-
ature setting shown on the front control display.
²REAR CONTROL± Selecting automatic control
of the rear unit at the instrument panel, illuminates
a Locked Padlock in the rear control panel display.
Selecting REAR activates the rear control panel and
the Padlock then appears unlocked.
²FAN KNOB± The rear fan control has Off and
AUTO positions and a range of manual speed set-
tings that override the AUTO setting.
²MODE KNOB± The mode control allows inter-
mediate seat occupants to manually override the
automatic mode and select any balance of air flow
between overhead and floor outlets from full over-
head to full floor.
²SET TEMP± The rear set temp control will
operate identical to the front controls. If the frontcontrol rear set temp button is pressed simulta-
neously with the rear control head, then the front
control head press events shall have priority, i.e. if
the front user presses Rear Set Temp down and the
rear user presses Set Temp up, then the rear set
temp will decrease.
DIAGNOSIS AND TESTING
A/C COOL DOWN TEST
The heater-A/C control module can perform an A/C
cool down test, which is a test performed during the
manufacturing process to confirm that the air condi-
tioning system is performing satisfactorily. This test
can also provide a quick confirmation of air condi-
tioning system performance to the service technician.
If the test is completed satisfactorily, no further ser-
vice is required. If the test is failed, proceed to the
A/C Performance Test to confirm the A/C system is
operating properly, or use a DRBIIItscan tool to
diagnose the A/C system control and distribution sys-
tems. Refer to the appropriate diagnostic informa-
tion.
MANUAL TEMPERATURE CONTROL
The front blower speed and rear blower speed (if
equipped with rear HVAC) must be set to High and
the evaporator temperature sensor must be greater
than 13É C (55É F) or the test will fail immediately.
The test is activated by depressing the A/C and Rear
Wipe/Wash buttons simultaneously and holding them
depressed for no less than five seconds. The Rear
Wipe/Wash and A/C LEDs will blink on and off until
the test is complete. If the LEDs stop blinking before
two minutes, then the cool down test has been com-
pleted successfully. If the two minutes expire without
the expansion valve temperature reaching -6É C (20É
F) less than the outside air temperature, then the
cool down test has been failed and further A/C sys-
tem diagnosis is required. If the test is failed, the
LEDs will continue to blink until the vehicle has
been driven for greater than 13 km (8 miles).
AUTOMATIC TEMPERATURE CONTROL
The ambient air temperature in the room where
the vehicle will be tested must be a minimum of 21É
C (70ÉF) for this test. The test is activated by
depressing the A/C and PWR buttons simultaneously
and holding them depressed for no less than four sec-
onds. The snowflake icon and the DELAY text in the
ATC display will blink on and off alternately until
the test is complete. If the snowflake icon and the
DELAY text stop blinking before two minutes, then
the cool down test has been completed successfully. If
the two minutes expire without the evaporator tem-
perature reaching -6É C (20É F) less than the evapo-
24 - 6 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

rator initial temperature, then the cool down test has
been failed and further A/C system diagnosis is
required. If the test is failed, the snowflake icon and
the DELAY text will continue to blink across ignition
cycles until the vehicle has been driven for greater
than 13 km (8 miles).
A/C PERFORMANCE TEST
The A/C system is designed to remove heat and
humidity from the air entering the passenger com-
partment. The evaporator, located in the HVAC hous-
ing, is cooled to temperatures near the freezing point.
As warm damp air passes over the fins in the A/C
evaporator, moisture in the air condenses to water,
dehumidifying the air. Condensation on the evapora-
tor fins reduces the evaporators ability to absorb
heat. During periods of high heat and humidity, an
A/C system will be less effective. With the instru-
ment control set to recirculation mode, only air from
the passenger compartment passes through the A/C
evaporator. As the passenger compartment air dehu-
midifies, A/C performance levels rise.
Humidity has an important bearing on the temper-
ature of the air delivered to the interior of the vehi-
cle. It is important to understand the effect that
humidity has on the performance of the A/C system.
When humidity is high, the A/C evaporator has to
perform a double duty. It must lower the air temper-
ature, and it must lower the temperature of the
moisture in the air that condenses on the evaporator
fins. Condensing the moisture in the air transfers
heat energy into the evaporator fins and tubing. This
reduces the amount of heat the A/C evaporator can
absorb from the air. High humidity greatly reduces
the ability of the A/C evaporator to lower the temper-
ature of the air.
However, evaporator capacity used to reduce the
amount of moisture in the air is not wasted. Wring-
ing some of the moisture out of the air entering the
vehicle adds to the comfort of the passengers.
Although, an owner may expect too much from their
A/C system on humid days. A performance test is the
best way to determine whether the system is per-
forming up to design standards. This test also pro-
vides valuable clues as to the possible cause of
trouble with the A/C system. The ambient air tem-perature in the location where the vehicle will be
tested must be a minimum of 21É C (70É F) for this
test.
PERFORMANCE TEST PROCEDURE
WARNING: REFER TO THE APPLICABLE WARN-
INGS AND CAUTIONS FOR THIS SYSTEM BEFORE
PERFORMING THE FOLLOWING OPERATION (Refer
to 24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - WARNING - A/C PLUMBING) and (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING -
FRONT - CAUTION - A/C PLUMBING).
NOTE: When connecting the service equipment
coupling to the line fitting, verify that the valve of
the coupling is fully closed. This will reduce the
amount of effort required to make the connection.
(1) Connect a tachometer and a manifold gauge
set.
(2) Set the mode control to the Recirculation Mode
position, the temperature control to the full cool posi-
tion and the blower to the highest speed position.
(3) Start the engine and hold at 1,000 rpm with
the A/C compressor clutch engaged.
(4) The engine should be warmed up to operating
temperature with the doors closed and windows
open.
(5) Insert a thermometer in the driver's side center
panel A/C-heater outlet and operate the engine for
five minutes.
(6) If the compressor clutch does not engage, pro-
ceed with diagnosis of the compressor clutch coil.
(Refer to 24 - HEATING & AIR CONDITIONING/
CONTROLS - FRONT/COMPRESSOR CLUTCH
COIL - DIAGNOSIS AND TESTING).
(7) With the A/C compressor clutch engaged, com-
pare the air temperature at the center panel outlet
and the compressor discharge pressure to the A/C
Performance Temperature and Pressure chart. The
compressor clutch may cycle, depending upon the
ambient temperature and humidity. If the clutch
cycles, use the readings obtained before the clutch
disengaged.
RSHEATING & AIR CONDITIONING24-7
HEATING & AIR CONDITIONING (Continued)

Condition Possible Causes Correction
The low side pressure is too
low, and the high side
pressure is too high.1. Restricted refrigerant flow
through the refrigerant lines.1. See Liquid Line, Suction Line and Discharge
Line in this group. Inspect the refrigerant lines for
kinks, tight bends or improper routing. Correct
the routing or replace the refrigerant line, if
required.
2. Restricted refrigerant flow
through the A/C expansion
valve.2. See A/C Expansion Valve in this group.
Replace the valve, if required.
3. Restricted refrigerant flow
through the A/C condenser.3. See A/C Condenser in this group. Replace the
restricted condenser, if required.
HEATER PERFORMANCE TEST
WARNING: REVIEW SAFETY PRECAUTIONS AND
WARNINGS IN THIS GROUP BEFORE PERFORMING
THIS PROCEDURE (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - WARNING).
Check the coolant level, drive belt tension, radiator
air flow and fan operation. Start engine and allow to
warm up to normal operating temperature.
WARNING: DO NOT REMOVE RADIATOR CAP
WHEN ENGINE IS HOT, PERSONAL INJURY CAN
RESULT.
If vehicle has been run recently, wait 15 minutes
before removing the radiator cap. Place a rag overthe cap and turn it to the first safety stop. Allow
pressure to escape through the overflow tube. When
the system pressure stabilizes, remove the cap com-
pletely.
MAXIMUM HEATER OUTPUT: TEST AND ACTION
Engine coolant is provided to the heater system by
two heater hoses. With the engine idling at normal
operating temperature, set the temperature control
to maximum heat, the mode control to the floor posi-
tion, and the blower in the highest speed position.
Using a test thermometer, check the temperature of
the air being discharged from the floor outlets. Com-
pare the test thermometer reading to the Tempera-
ture Reference chart.
TEMPERATURE REFERENCE
Ambient Temperature Minimum Floor Outlet Temperature
Celsius Fahrenheit Celsius Fahrenheit
15.5É 60É 62.2É 144É
21.1É 70É 63.8É 147É
26.6É 80É 65.5É 150É
32.2É 90É 67.2É 153É
If the floor outlet air temperature is insufficient,
check that the cooling system is operating to specifi-
cations (Refer to 7 - COOLING/ENGINE - DIAGNO-
SIS AND TESTING). Both heater hoses should be
HOT to the touch (the coolant return hose should be
slightly cooler than the supply hose). If the coolant
return hose is much cooler than the supply hose,
locate and repair the engine coolant flow obstruction
in heater system.
OBSTRUCTED COOLANT FLOW Possible locations or causes
of obstructed coolant flow are as follows:
²Pinched or kinked heater hoses.
²Improper heater hose routing.²Plugged heater hoses or supply and return ports
at the cooling system connections.
²Plugged heater core.
If proper coolant flow through the cooling system is
verified, and heater outlet air temperature is insuffi-
cient, a mechanical problem may exist.
MECHANICAL PROBLEMS
Possible causes of insufficient heat due to mechan-
ical problems are as follows:
²Obstructed cowl air intake.
²Obstructed heater system outlets.
²Blend door not functioning properly.
24 - 10 HEATING & AIR CONDITIONINGRS
HEATING & AIR CONDITIONING (Continued)

TEMPERATURE CONTROL
If the heater outlet air temperature cannot be
adjusted with the temperature control knob on the
A/C-heater control panel, the following could require
service:
²Blend door binding.
²Faulty blend door actuator.
²Faulty A/C-heater control.
²Faulty related wiring harness or connectors.²Improper engine coolant temperature.
SPECIFICATIONS
A/C SYSTEM
The R-134a refrigerant system charge capacity for
this vehicle can be found on the underhood Specifica-
tion Label.
SYSTEM SPECIFICATIONS
Item Description Notes
A/C Compressor Denso 10S17 ± 2.4L/2.5L/2.8L/3.3L
without rear A/C
Denso 10S20 ± 3.3L/3.8L with rear
A/CND-8 PAG Oil
Freeze±up Control Evaporator temperature sensor HVAC housing mounted (RS models),
Evaporator mounted (RG models) - input to
A/C-heater control module
Low PSI Control A/C pressure transducer Liquid line mounted - input to Powertrain Control
Module (PCM) - PCM opens compressor clutch
relay above 200 kPa (29 psi)
High PSI Control A/C pressure transducer Liquid line mounted - input to PCM - PCM
opens compressor clutch relay below 3100 kPa
(450 psi)
High Pressure relief valve Compressor mounted - opens above 3445-4135
kPa (500-600 psi), closes below 2756 kPa (400
psi)
Compressor Clutch Coil
DrawDenso 10S17 ± 3.3 amps @ 12V  
0.5V @ 21É C (70É F)
Denso 10S20 ± 2.2 amps @ 12V  
0.5V @ 21É C (70É F)
Compressor Clutch Air
Gap0.35 - 0.60 mm (0.014 - 0.024 in.)
TORQUE SPECIFICATIONS
Description N´m Ft. Lbs. In. Lbs.
A/C Compressor Shaft Bolt 17.5 ± 155
A/C Compressor Mounting Bolts (2.4L/2.5L/2.8L) 28 21 ±
A/C Compressor Mounting Bolts (3.3L/3.8L) 54 40 ±
A/C Compressor Mounting Bracket Bolts (2.4L) 54 40 ±
A/C Condenser Mounting Bracket Screws 5 ± 45
A/C Expansion Valve Screws 11 ± 97
A/C-Heater Control Screws 2 ± 17
Blend Door Actuator Screws 2 ± 17
Blower Motor Screws 2 ± 17
Blower Motor Power Module Screws (ATC) 2 ± 17
Blower Motor Resistor Block Screws (MTC) 2 ± 17
Center Bezel Outlet Screws 2 ± 17
RSHEATING & AIR CONDITIONING24-11
HEATING & AIR CONDITIONING (Continued)