heater CHRYSLER VOYAGER 2005 Manual Online

(9) Install crankshaft vibration damper. (Refer to 9
- ENGINE/ENGINE BLOCK/VIBRATION DAMPER -
INSTALLATION)
(10) Install engine mount bracket (Fig. 137) and
tighten M10 to 54 N´m (40 ft. lbs.), M8 bolt to 28
N´m (21 ft. lb. lbs.).
(11) Install idler pulley on engine mount bracket
(Fig. 137).
(12) Install right side engine mount. (Refer to 9 -
ENGINE/ENGINE MOUNTING/RIGHT MOUNT -
INSTALLATION)
(13) Install camshaft position sensor (Refer to 8 -
ELECTRICAL/IGNITION CONTROL/CAMSHAFT
POSITION SENSOR - INSTALLATION).
(14) Connect the heater return hose at rear of tim-
ing chain cover (Fig. 135) or at water pump inlet
tube (if engine oil cooler equipped) (Fig. 136).
(15) Connect the radiator lower hose.
(16) Install A/C compressor.
Fig. 139 Timing Chain Cover and Gasket
1 - GASKET
2 - TIMING CHAIN COVER
Fig. 140 TIMING CHAIN COVER BOLT LOCATIONS
1 - BOLT - M8 x 1.25 x 95 4 - BOLT - M8 x 1.25 x 80
2 - BOLT - M10 x 1.5 x 100 5 - BOLT - M8 x 1.25 x 45
3 - BOLT - M10 x 1.5 x 85
9 - 158 ENGINE 3.3/3.8LRS
TIMING CHAIN COVER (Continued)

1 second. Therefore, battery voltage is not supplied to
the fuel pump, ignition coil, fuel injectors and heated
oxygen sensors.
ENGINE START-UP MODE
This is an OPEN LOOP mode. If the vehicle is in
park or neutral (automatic transaxles) or the clutch
pedal is depressed (manual transaxles) the ignition
switch energizes the starter relay when the engine is
not running. The following actions occur when the
starter motor is engaged.
²If the PCM receives the camshaft position sensor
and crankshaft position sensor signals, it energizes
the Auto Shutdown (ASD) relay and fuel pump relay.
If the PCM does not receive both signals within
approximately one second, it will not energize the
ASD relay and fuel pump relay. The ASD and fuel
pump relays supply battery voltage to the fuel pump,
fuel injectors, ignition coil, (EGR solenoid and PCV
heater if equipped) and heated oxygen sensors.
²The PCM energizes the injectors (on the 69É
degree falling edge) for a calculated pulse width until
it determines crankshaft position from the camshaft
position sensor and crankshaft position sensor sig-
nals. The PCM determines crankshaft position within
1 engine revolution.
²After determining crankshaft position, the PCM
begins energizing the injectors in sequence. It adjusts
injector pulse width and controls injector synchroni-
zation by turning the individual ground paths to the
injectors On and Off.
²When the engine idles within  64 RPM of its
target RPM, the PCM compares current MAP sensor
value with the atmospheric pressure value received
during the Ignition Switch On (zero RPM) mode.
Once the ASD and fuel pump relays have been
energized, the PCM determines injector pulse width
based on the following:
²MAP
²Engine RPM
²Battery voltage
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)
²Throttle position
²The number of engine revolutions since cranking
was initiated
During Start-up the PCM maintains ignition tim-
ing at 9É BTDC.
ENGINE WARM-UP MODE
This is an OPEN LOOP mode. The following inputs
are received by the PCM:
²Manifold Absolute Pressure (MAP)
²Crankshaft position (engine speed)
²Engine coolant temperature
²Inlet/Intake air temperature (IAT)²Camshaft position
²Knock sensor
²Throttle position
²A/C switch status
²Battery voltage
²Vehicle speed
²Speed control
²O2 sensors
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts ignition timing and engine idle
speed. Engine idle speed is adjusted through the idle
air control motor.
CRUISE OR IDLE MODE
When the engine is at operating temperature this
is a CLOSED LOOP mode. During cruising or idle
the following inputs are received by the PCM:
²Manifold absolute pressure
²Crankshaft position (engine speed)
²Inlet/Intake air temperature
²Engine coolant temperature
²Camshaft position
²Knock sensor
²Throttle position
²Exhaust gas oxygen content (O2 sensors)
²A/C switch status
²Battery voltage
²Vehicle speed
The PCM adjusts injector pulse width and controls
injector synchronization by turning the individual
ground paths to the injectors On and Off.
The PCM adjusts engine idle speed and ignition
timing. The PCM adjusts the air/fuel ratio according
to the oxygen content in the exhaust gas (measured
by the upstream and downstream heated oxygen sen-
sor).
The PCM monitors for engine misfire. During
active misfire and depending on the severity, the
PCM either continuously illuminates or flashes the
malfunction indicator lamp (Check Engine light on
instrument panel). Also, the PCM stores an engine
misfire DTC in memory, if 2nd trip with fault.
The PCM performs several diagnostic routines.
They include:
²Oxygen sensor monitor
²Downstream heated oxygen sensor diagnostics
during open loop operation (except for shorted)
²Fuel system monitor
²EGR monitor (if equipped)
²Purge system monitor
²Catalyst efficiency monitor
²All inputs monitored for proper voltage range,
rationality.
RSFUEL INJECTION14-23
FUEL INJECTION (Continued)

²All monitored components (refer to the Emission
section for On-Board Diagnostics).
The PCM compares the upstream and downstream
heated oxygen sensor inputs to measure catalytic
convertor efficiency. If the catalyst efficiency drops
below the minimum acceptable percentage, the PCM
stores a diagnostic trouble code in memory, after 2
trips.
During certain idle conditions, the PCM may enter
a variable idle speed strategy. During variable idle
speed strategy the PCM adjusts engine speed based
on the following inputs.
²A/C status
²Battery voltage
²Battery temperature or Calculated Battery Tem-
perature
²Engine coolant temperature
²Engine run time
²Inlet/Intake air temperature
²Vehicle mileage
ACCELERATION MODE
This is a CLOSED LOOP mode. The PCM recog-
nizes an abrupt increase in Throttle Position sensor
output voltage or MAP sensor output voltage as a
demand for increased engine output and vehicle
acceleration. The PCM increases injector pulse width
in response to increased fuel demand.
²Wide Open Throttle-open loop
DECELERATION MODE
This is a CLOSED LOOP mode. During decelera-
tion the following inputs are received by the PCM:
²A/C status
²Battery voltage
²Inlet/Intake air temperature
²Engine coolant temperature
²Crankshaft position (engine speed)
²Exhaust gas oxygen content (upstream heated
oxygen sensor)
²Knock sensor
²Manifold absolute pressure
²Throttle position sensor
²IAC motor (solenoid) control changes in response
to MAP sensor feedback
The PCM may receive a closed throttle input from
the Throttle Position Sensor (TPS) when it senses an
abrupt decrease in manifold pressure. This indicates
a hard deceleration (Open Loop). In response, the
PCM may momentarily turn off the injectors. This
helps improve fuel economy, emissions and engine
braking.
WIDE-OPEN-THROTTLE MODE
This is an OPEN LOOP mode. During wide-open-
throttle operation, the following inputs are used by
the PCM:
²Inlet/Intake air temperature
²Engine coolant temperature
²Engine speed
²Knock sensor
²Manifold absolute pressure
²Throttle position
When the PCM senses a wide-open-throttle condi-
tion through the Throttle Position Sensor (TPS) it de-
energizes the A/C compressor clutch relay. This
disables the air conditioning system and disables
EGR (if equipped).
The PCM adjusts injector pulse width to supply a
predetermined amount of additional fuel, based on
MAP and RPM.
IGNITION SWITCH OFF MODE
When the operator turns the ignition switch to the
OFF position, the following occurs:
²All outputs are turned off, unless 02 Heater
Monitor test is being run. Refer to the Emission sec-
tion for On-Board Diagnostics.
²No inputs are monitored except for the heated
oxygen sensors. The PCM monitors the heating ele-
ments in the oxygen sensors and then shuts down.
FUEL CORRECTION or ADAPTIVE MEMORIES
DESCRIPTION
In Open Loop, the PCM changes pulse width with-
out feedback from the O2 Sensors. Once the engine
warms up to approximately 30 to 35É F, the PCM
goes into closed loopShort Term Correctionand
utilizes feedback from the O2 Sensors. Closed loop
Long Term Adaptive Memoryis maintained above
170É to 190É F unless the PCM senses wide open
throttle. At that time the PCM returns to Open Loop
operation.
OPERATION
Short Term
The first fuel correction program that begins func-
tioning is the short term fuel correction. This system
corrects fuel delivery in direct proportion to the read-
ings from the Upstream O2 Sensor.
The PCM monitors the air/fuel ratio by using the
input voltage from the O2 Sensor. When the voltage
reaches its preset high or low limit, the PCM begins
to add or remove fuel until the sensor reaches its
switch point. The short term corrections then begin.
The PCM makes a series of quick changes in the
injector pulse-width until the O2 Sensor reaches its
14 - 24 FUEL INJECTIONRS
FUEL INJECTION (Continued)

present (caused by a lean air/fuel mixture, can be
caused by misfire and exhaust leaks), the sensors
produces a low voltage. When there is a lesser
amount of oxygen present (caused by a rich air/fuel
mixture, can be caused by internal engine problems)
it produces a higher voltage. By monitoring the oxy-
gen content and converting it to electrical voltage,
the sensors act as a rich-lean switch.
The oxygen sensors are equipped with a heating
element that keeps the sensors at proper operating
temperature during all operating modes. Maintaining
correct sensor temperature at all times allows the
system to enter into closed loop operation sooner.
Also, it allows the system to remain in closed loop
operation during periods of extended idle.
In Closed Loop operation the PCM monitors the O2
sensors input (along with other inputs) and adjusts
the injector pulse width accordingly. During Open
Loop operation the PCM ignores the O2 sensor input.
The PCM adjusts injector pulse width based on pre-
programmed (fixed) values and inputs from other
sensors.
NGC Controller - Has a common ground for the
heater in the O2S. 12 volts is supplied to the heater
in the O2S by the NGC controller. Both the upstream
and downstream O2 sensors for NGC are pulse width
modulation (PWM).NOTE: When replacing an O2
Sensor, the PCM RAM memory must be cleared,
either by disconnecting the PCM C-1 connector or
momentarily disconnecting the Battery negative ter-
minal. The NGC learns the characteristics of each O2
heater element and these old values should be
cleared when installing a new O2 sensor. The cus-
tomer may experience driveability issues if this is not
performed.
UPSTREAM OXYGEN SENSOR
The input from the upstream heated oxygen sensor
tells the PCM the oxygen content of the exhaust gas.
Based on this input, the PCM fine tunes the air-fuel
ratio by adjusting injector pulse width.
The sensor input switches from 2.5 to 3.5 volt,
depending upon the oxygen content of the exhaust
gas in the exhaust manifold. When a large amount ofoxygen is present (caused by a lean air-fuel mixture),
the sensor produces voltage as low as 2.5 volt. When
there is a lesser amount of oxygen present (rich air-
fuel mixture) the sensor produces a voltage as high
as 3.5 volt. By monitoring the oxygen content and
converting it to electrical voltage, the sensor acts as
a rich-lean switch.
The heating element in the sensor provides heat to
the sensor ceramic element. Heating the sensor
allows the system to enter into closed loop operation
sooner. Also, it allows the system to remain in closed
loop operation during periods of extended idle.
In Closed Loop, the PCM adjusts injector pulse
width based on the upstream heated oxygen sensor
input along with other inputs. In Open Loop, the
PCM adjusts injector pulse width based on prepro-
grammed (fixed) values and inputs from other sen-
sors.
DOWNSTREAM OXYGEN SENSOR
The downstream heated oxygen sensor input is
used to detect catalytic convertor deterioration. As
the convertor deteriorates, the input from the down-
stream sensor begins to match the upstream sensor
input except for a slight time delay. By comparing
the downstream heated oxygen sensor input to the
input from the upstream sensor, the PCM calculates
catalytic convertor efficiency. Also used to establish
the upstream O2 goal voltage (switching point).
REMOVAL
REMOVAL - UPSTREAM 1/1 - 2.4L
(1) Disconnect the negative battery cable.
(2) Raise and support the vehicle.
(3) Disconnect the electrical connector (Fig. 23).
(4) Use a socket such as the Snap-OntYA8875 or
equivalent to remove the sensor
(5) When the sensor is removed, the threads must
be cleaned with an 18 mm X 1.5 + 6E tap. If using
the original sensor, coat the threads with Loctite
771±64 anti-seize compound or equivalent.
RSFUEL INJECTION14-37
O2 SENSOR (Continued)

the vehicle should not enter the passenger or luggage
compartment. Moving sealing surfaces will not
always seal water tight under all conditions. At
times, side glass or door seals will allow water to
enter the passenger compartment during high pres-
sure washing or hard driving rain (severe) condi-
tions. Overcompensating on door or glass
adjustments to stop a water leak that occurs under
severe conditions can cause premature seal wear and
excessive closing or latching effort. After completing
a repair, water test vehicle to verify leak has stopped
before returning vehicle to use.
VISUAL INSPECTION BEFORE WATER LEAK TESTS
Verify that floor and body plugs are in place, body
drains are clear, and body components are properly
aligned and sealed. If component alignment or seal-
ing is necessary, refer to the appropriate section of
this group for proper procedures.
WATER LEAK TESTS
WARNING: DO NOT USE ELECTRIC SHOP LIGHTS
OR TOOLS IN WATER TEST AREA. PERSONAL
INJURY CAN RESULT.
When the conditions causing a water leak have
been determined, simulate the conditions as closely
as possible.
²If a leak occurs with the vehicle parked in a
steady light rain, flood the leak area with an open-
ended garden hose.
²If a leak occurs while driving at highway speeds
in a steady rain, test the leak area with a reasonable
velocity stream or fan spray of water. Direct the
spray in a direction comparable to actual conditions.
²If a leak occurs when the vehicle is parked on an
incline, hoist the end or side of the vehicle to simu-
late this condition. This method can be used when
the leak occurs when the vehicle accelerates, stops or
turns. If the leak occurs on acceleration, hoist the
front of the vehicle. If the leak occurs when braking,
hoist the back of the vehicle. If the leak occurs on left
turns, hoist the left side of the vehicle. If the leak
occurs on right turns, hoist the right side of the vehi-
cle. For hoisting recommendations (Refer to LUBRI-
CATION & MAINTENANCE/HOISTING -
STANDARD PROCEDURE).
WATER LEAK DETECTION
To detect a water leak point-of-entry, do a water
test and watch for water tracks or droplets forming
on the inside of the vehicle. If necessary, remove inte-
rior trim covers or panels to gain visual access to the
leak area. If the hose cannot be positioned without
being held, have someone help do the water test.Some water leaks must be tested for a considerable
length of time to become apparent. When a leak
appears, find the highest point of the water track or
drop. The highest point usually will show the point of
entry. After leak point has been found, repair the
leak and water test to verify that the leak has
stopped.
Locating the entry point of water that is leaking
into a cavity between panels can be difficult. The
trapped water may splash or run from the cavity,
often at a distance from the entry point. Most water
leaks of this type become apparent after accelerating,
stopping, turning, or when on an incline.
MIRROR INSPECTION METHOD
When a leak point area is visually obstructed, use
a suitable mirror to gain visual access. A mirror can
also be used to deflect light to a limited-access area
to assist in locating a leak point.
BRIGHT LIGHT LEAK TEST METHOD
Some water leaks in the luggage compartment can
be detected without water testing. Position the vehi-
cle in a brightly lit area. From inside the darkened
luggage compartment inspect around seals and body
seams. If necessary, have a helper direct a drop light
over the suspected leak areas around the luggage
compartment. If light is visible through a normally
sealed location, water could enter through the open-
ing.
PRESSURIZED LEAK TEST METHOD
When a water leak into the passenger compart-
ment cannot be detected by water testing, pressurize
the passenger compartment and soap test exterior of
the vehicle. To pressurize the passenger compart-
ment, close all doors and windows, start engine, and
set heater control to high blower in HEAT position. If
engine can not be started, connect a charger to the
battery to ensure adequate voltage to the blower.
With interior pressurized, apply dish detergent solu-
tion to suspected leak area on the exterior of the
vehicle. Apply detergent solution with spray device or
soft bristle brush. If soap bubbles occur at a body
seam, joint, seal or gasket, the leak entry point could
be at that location.
WIND NOISE
Wind noise is the result of most air leaks. Air leaks
can be caused by poor sealing, improper body compo-
nent alignment, body seam porosity, or missing plugs
in the engine compartment or door hinge pillar areas.
All body sealing points should be airtight in normal
driving conditions. Moving sealing surfaces will not
always seal airtight under all conditions. At times,
side glass or door seals will allow wind noise to be
23 - 2 BODYRS
BODY (Continued)

INSTALLATION
NOTE: The crossbar assemblies are designed to be
installed in only one way. Check top and bottom
surfaces of the crossbar for the word FRONT and
directional arrows. The directional arrows must
point toward the front of the vehicle.
(1) Place crossbar in position on vehicle.
(2) Work from side to side sliding the crossbar
assembly back a little at a time to ensure it remains
perpendicular to the side rails.
(3) Position first crossbar assembly crossbar at the
second most rearward locator holes. Press the top of
the stanchion lever to lock it into position.
(4) Position the second crossbar assembly in the
second hole from the front. Lock into place.
(5) Place luggage rack riser into position.
(6) Install two fasteners into riser. Tighten fasten-
ers to 4 mm (35 in. lbs.) torque.
REAR QUARTER PANEL/
FENDER AIR EXHAUSTER
DESCRIPTION
Air exhausters, designed to conform to the body
structure, allow air entering at the front of the vehi-
cle to flow out the back. By reducing air pressure
within the vehicle, the exhausters also reduce blower
noise at any given air flow level compared to operat-
ing without them and help reduce door closing effort.
They are located in the lower rear comers of the
body.
REMOVAL
SHORT WHEELBASE
(1) Remove the rear fascia from the body. (Refer to
13 - FRAMES & BUMPERS/BUMPERS/REAR FAS-
CIA - REMOVAL).
(2) Using a trim stick or another suitable wide flat
bladed tool, carefully pry the air exhauster away
from the opening in the lower aperture panel until
the snap features release (Fig. 21).
(3) Remove the air exhauster from the hole in the
lower aperture panel.
LONG WHEELBASE
NOTE: Models with the optional rear heater and air
conditioner do not have an air exhauster on the
right side of the vehicle, but have a plastic plug
installed in the right lower aperture panel. This plug
is removed using the same procedure used toremove the air exhauster from the short wheelbase
model. Refer to SHORT WHEELBASE.
(1) Remove the quarter trim panel from the inside
of the left or right quarter inner panel (Refer to 23 -
BODY/INTERIOR/RIGHT QUARTER TRIM PANEL
- REMOVAL) or (Refer to 23 - BODY/INTERIOR/
LEFT QUARTER TRIM PANEL - REMOVAL).
(2) Using a trim stick or another suitable wide flat
bladed tool, carefully pry the air exhauster away
from the opening in the lower aperture panel until
the snap features release (Fig. 22).
(1) Remove the air exhauster from the hole in the
lower aperture panel.
Fig. 21 AIR EXHAUSTER - SWB
1 - LOWER APERTURE PANEL
2 - AIR EXHAUSTER
Fig. 22 AIR EXHAUSTER - LWB
1 - AIR EXHAUSTER
2 - PLUG
3 - LOWER APERTURE PANEL
RSEXTERIOR23-59
LUGGAGE RACK CROSSBAR (Continued)

INSTALLATION
SHORT WHEELBASE
(1) Position the air exhauster to the hole in the
lower aperture panel (Fig. 21).
(2) Using hand pressure, press the air exhauster
into the opening in the lower aperture panel until
the snap features are fully engaged.
(3) Reinstall the rear fascia onto the body. (Refer
to 13 - FRAMES & BUMPERS/BUMPERS/REAR
FASCIA - INSTALLATION).
LONG WHEELBASE
NOTE: Models with the optional rear heater and air
conditioner do not have an air exhauster on the
right side of the vehicle, but have a plastic plug
installed in the right lower aperture panel. This plug
is installed using the same procedure used to
install the air exhauster onto the short wheelbase
model. Refer to SHORT WHEELBASE.
(1) Position the air exhauster to the hole in the
lower aperture panel (Fig. 22).
(2) Using hand pressure, press the air exhauster
into the opening in the lower aperture panel until
the snap features are fully engaged.
(3) Reinstall the quarter trim panel onto the inside
of the left or right quarter inner panel. (Refer to 23 -
BODY/INTERIOR/RIGHT QUARTER TRIM PANEL
- INSTALLATION) or (Refer to 23 - BODY/INTERI-
OR/LEFT QUARTER TRIM PANEL - INSTALLA-
TION).
ROOF JOINT MOLDING
REMOVAL
The RAP molding is set with body side molding
tape. The temperature in the work area and the vehi-
cle should be at least 21É C (70É F) to avoid damag-
ing the RAP moldings.
(1) Warm the affected stick-on molding and body
metal to approximately 38É C (100É F) using a suit-
able heat lamp or heat gun.
(2) Pull stick-on molding from painted surface.
(3) Remove adhesive tape residue from painted
surface of vehicle. Use a 3M Scotch-BriteŸ Molding
Adhesive and Stripe Removal Discs, or equivalent, to
clean adhesive residue from painted surfaces. The
adhesive removal discs are available from automotive
paint suppliers. Refer to instructions supplied with
the discs for proper usage.
INSTALLATION
The RAP molding is set with body side molding
tape. The temperature in the work area and the vehi-
cle should be at least 21É C (70É F) to avoid damag-
ing the RAP moldings.
(1) If molding is to be reused;
(a) Remove tape residue from molding.
(b) Clean back of molding with MopartSuper
Kleen solvent, or equivalent.
(c) Wipe molding dry with lint free cloth.
(d) Apply new body side molding (two sided
adhesive) tape to back of molding.
(2) Clean body surface with MopartSuper Kleen
solvent, or equivalent. Wipe surface dry with lint free
cloth.
(3) Remove protective cover from tape on back of
molding.
(4) Apply molding to body from front of vehicle to
rear.
(5) Using a roller tool, roll molding onto body
panel with enough force to assure adhesion and not
bend roof panels.
SIDE VIEW MIRROR
REMOVAL
(1) Using a trim stick C-4755 or equivalent, lift up
the end of the instrument panel top pad enough to
gain access to the mirror electrical connector, if
equipped. (Refer to 23 - BODY/INSTRUMENT PAN-
EL/INSTRUMENT PANEL TOP COVER -
REMOVAL)
(2) Disconnect the electrical connector, if equipped.
(3) Using a trim stick or equivalent, remove the
trim cover (Fig. 23).
(4) Remove the bolts.
(5) Remove the mirror from the pillar.
INSTALLATION
(1) Route the mirror wire harness, if equipped,
through the a-pillar and place side view mirror in
position on vehicle (Fig. 23).
(2) Install the bolts and tighten to 10 N´m (85 in.
lbs.).
(3) Install the mirror trim cover.
(4) Connect the electrical connector, if equipped.
(5) Install the instrument panel top cover, if
equipped with the electric mirror. (Refer to 23 -
BODY/INSTRUMENT PANEL/INSTRUMENT
PANEL TOP COVER - INSTALLATION)
23 - 60 EXTERIORRS
REAR QUARTER PANEL/FENDER AIR EXHAUSTER (Continued)

HEATING & AIR CONDITIONING
TABLE OF CONTENTS
page page
HEATING & AIR CONDITIONING
DESCRIPTION
ENGINE COOLING SYSTEM
REQUIREMENTS.......................1
HEATER AND AIR CONDITIONER..........1
MANUAL SINGLE ZONE.................2
MANUAL DUAL ZONE...................2
MANUAL THREE ZONE..................2
AUTOMATIC TEMPERATURE CONTROL....3
OPERATION
HEATER AND AIR CONDITIONER..........4
MANUAL SINGLE ZONE.................4
MANUAL DUAL ZONE...................5
MANUAL THREE ZONE..................5AUTOMATIC TEMPERATURE CONTROL....5
DIAGNOSIS AND TESTING
A/C COOL DOWN TEST.................6
A/C PERFORMANCE TEST...............7
HEATER PERFORMANCE TEST..........10
SPECIFICATIONS
A/C SYSTEM.........................11
CONTROLS - FRONT.....................13
CONTROLS - REAR......................33
DISTRIBUTION - FRONT...................42
DISTRIBUTION - REAR....................56
PLUMBING - FRONT.....................64
PLUMBING - REAR......................98
CABIN HEATER........................113
HEATING & AIR
CONDITIONING
DESCRIPTION
ENGINE COOLING SYSTEM REQUIREMENTS
To maintain the performance level of the heating,
ventilation and air conditioning (HVAC) system, the
engine cooling system must be properly maintained.
The use of a bug screen is not recommended. Any
obstructions in front of the radiator or condenser will
reduce the performance of the air conditioning and
engine cooling systems.
The engine cooling system includes the radiator,
thermostat, radiator hoses and the engine coolant
pump. Refer to Cooling for more information before
opening or attempting any service to the engine cool-
ing system.
HEATER AND AIR CONDITIONER
A manually controlled single zone type heating-air
conditioning system, manually controlled dual zone
type heating-air conditioning system, manually con-
trolled three zone type heating-air conditioning sys-
tem or an automatic controlled three zone type
heating-air conditioning system is available on this
model.
All vehicles are equipped with a common heater,
ventilation and air conditioning (HVAC) housing (Fig.
1). The system combines air conditioning, heating,
and ventilating capabilities in a single unit housingmounted within the passenger compartment under
the instrument panel. The HVAC housing includes:
²Blower motor
²Blower motor resistor block or power module
(depending on application)
²Heater core
²Evaporator coil
²Blend door and actuator
²Mode door and actuator
²Recirculation door and actuator
Based upon the system and mode selected, condi-
tioned air can exit the HVAC housing through one or
Fig. 1 HVAC Housing - LHD Shown, RHD Typical
1 - HVAC HOUSING
2 - BOLT
3 - BRACKET
4 - DASH PANEL
RSHEATING & AIR CONDITIONING24-1

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.
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HEATING & AIR CONDITIONING (Continued)