2004 CHRYSLER VOYAGER heating

REMOVAL - ENGINE ASSEMBLY
(1) Perform fuel pressure release procedure (Refer
to 14 - FUEL SYSTEM/FUEL DELIVERY - STAN-
DARD PROCEDURE)
(2) Disconnect battery negative cable.
(3) Remove air cleaner housing and inlet tube.
(4) Disconnect the fuel line from fuel rail. (Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- STANDARD PROCEDURE)
(5) Disconnect all vacuum hoses.
(6) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(7) Remove radiator fans. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL)
(8) Remove radiator upper and lower hoses.
NOTE: When the transaxle cooler lines are removed
from the rolled-groove type fittings at the transaxle,
damage to the inner wall of the hose will occur. To
prevent prevent potential leakage, the cooler hoses
must be cut off flush at the transaxle fitting, and a
service cooler hose splice kit must be installed
upon reassembly.(9) Using a blade or suitable hose cutter, cut trans-
axle oil cooler lines off flush with fittings. Plug cooler
lines and fittings to prevent debris from entering
transaxle or cooler circuit. A service splice kit will be
installed upon reassembly.
(10) Disconnect transmission shift linkage and
electrical connectors.
(11) Disconnect throttle body linkage.
(12) Disconnect engine wiring harness.
(13) Disconnect heater hoses from heater (Fig. 5).
(14) Discharge air conditioning system. (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE)
(15) Hoist vehicle and remove front wheels and
tires.
(16) Remove accessory drive belt splash shield.
(17) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
Fig. 5 HEATER HOSES - 2.4L
1 - HEATER HOSES TO HEATER 3 - HEATER HOSE TO ENGINE - SUPPLY AND RETURN
2 - BOLT - HEATER TUBE SUPPORT
RSENGINE 2.4L9-13
ENGINE 2.4L (Continued)

AIR CLEANER ELEMENT
REMOVAL
(1) Unsnap 2 clips.
(2) Lift cover and pull toward the engine and
remove cover tabs from air box.
(3) Lift cover and remove the element (Fig. 11).
INSTALLATION
(1) Install the air filter element into air box (Fig.
11).
(2) Move cover so that the tabs insert into the air
box.
(3) Push cover down and snap the 2 clips.
AIR CLEANER HOUSING
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the inlet air temperature sensor
(Fig. 12).
(3) Remove the inlet hose to throttle body (Fig. 11).
(4) Remove the bolt for air box at upper radiator
cross member.
(5) Pull air box up and off over the single locating
pin.
(6) Remove air box from vehicle
INSTALLATION
(1) Install air box into vehicle and onto the locat-
ing pin.(2) Install bolt to hold air box to the upper radia-
tor cross member.
(3) Install the inlet hose to the throttle body.
(4) Connect the inlet air temperature sensor (Fig.
12).
(5) Connect the negative battery cable.
CYLINDER HEAD
DESCRIPTION
The cross flow designed, aluminum cylinder head
contains dual over-head camshafts with four valves
per cylinder (Fig. 13). The valves are arranged in two
in-line banks. The intake valves face toward the
front of the vehicle. The exhaust valves face the dash
panel. The cylinder head incorporates powdered
metal valve guides and seats. The cylinder head is
sealed to the block using a multi-layer steel head
gasket and retaining bolts.
Integral oil galleries provide lubrication passages
to the hydraulic lash adjusters, camshafts, and valve
mechanisms.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
Fig. 11 AIR BOX COVER
Fig. 12 IAT SENSOR 2.4L
9 - 24 ENGINE 2.4LRS

(11) Disconnect the throttle cables from the throt-
tle body.
(12) Disconnect the MAP, IAC, and TPS electrical
connectors.
(13) Disconnect the EGR transducer electrical con-
nector (if equipped).
(14) Disconnect the vacuum hoses from throttle
body.
(15) Disconnect the brake booster and speed con-
trol vacuum hoses.
(16) Disengage wire harness clip from the right
side engine mount.
(17) Remove the power steering reservoir from
mounting position and set aside.Do notdisconnect
hose.
(18) Disconnect ground strap from rear of cylinder
head.
(19) Disconnect engine coolant temperature (ECT)
sensor and ignition coil electrical connectors.
(20) Disconnect the fuel injector electrical harness
connector and disengage clip from support bracket.
(21) Disconnect camshaft and crankshaft position
sensor electrical connectors.
(22) Evacuate air conditioning system. Refer to 24
- HEATING & AIR CONDITIONING.
(23) Disconnect A/C compressor electrical connec-
tor.
(24) Disconnect the A/C lines from compressor.
Cover and seal all openings of hoses and compressor.
(25) Remove the radiator upper hose.
(26) Disengage electrical harness clip at transaxle
dipstick tube.
(27) Remove transaxle dipstick tube. Seal opening
using a suitable plug.
NOTE: When the transaxle cooler lines are removed
from the rolled-groove type fittings at the transaxle,
damage to the inner wall of the hose will occur. To
prevent prevent potential leakage, the cooler hoses
must be cut off flush at the transaxle fitting, and a
service cooler hose splice kit must be installed
upon reassembly.
(28) Using a blade or suitable hose cutter, cut
transaxle oil cooler lines off flush with fittings. Plug
cooler lines and fittings to prevent debris from enter-
ing transaxle or cooler circuit. A service splice kit will
be installed upon reassembly.
(29) Disconnect transaxle shift linkage and electri-
cal connectors.
(30)
Raise vehicle on hoist and drain the engine oil.
(31) Remove the axle shafts. (Refer to 3 - DIFFER-
ENTIAL & DRIVELINE/HALF SHAFT - REMOVAL)
(32) Remove crossmember cradle plate (Fig. 6).
(33)AWD equipped:Remove the power transfer
unit (PTU) (Refer to 21 - TRANSMISSION/TRANS-
AXLE/POWER TRANSFER UNIT - REMOVAL).(34) Disconnect exhaust pipe from the manifold
(Fig. 7).
(35) Remove front engine mount and bracket as an
assembly.
(36) Remove the engine rear mount bracket.
(37) Remove the engine to transaxle struts (Fig. 8).
(38) Remove transaxle case cover (Fig. 8).
(39) Remove flex plate to torque converter bolts.
Mark torque converter to flex plate for orientation for
reassembly.
(40) Remove the power steering pressure hose sup-
port clip attaching bolt.
Fig. 6 Crossmember Cradle Plate
1 - CRADLE PLATE
Fig. 7 Catalytic Converter to Exhaust Manifold
1 - FLAG NUT
2 - GASKET
3 - BOLT
4 - CATALYTIC CONVERTER
RSENGINE 3.3/3.8L9-87
ENGINE 3.3/3.8L (Continued)

AIR CLEANER HOUSING
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the inlet air temperature sensor
(Fig. 16).
(3) Remove the inlet hose to throttle body.
(4) Remove the bolt for air box at upper radiator
cross member.
(5) Pull air box up and off over the single locating
pin.
(6) Remove air box from vehicle
INSTALLATION
(1) Install air box into vehicle and onto the locat-
ing pin.
(2) Install bolt to hold air box to the upper radia-
tor cross member.
(3) Install the inlet hose to the throttle body.
(4) Connect the inlet air temperature sensor (Fig.
16).
(5) Connect the negative battery cable.
CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 17) are
designed to create high flow combustion chambers to
improve performance, while minimizing the change
to the burn rate in the chamber. The cylinder head
incorporates the combustion chamber. Two valves
per-cylinder are used with inserted valve seats and
guides. A multi-layer steel (MLS) type gasket is used
between the cylinder head and engine block.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
Fig. 16 Inlet Air Temperature Sensor
RSENGINE 3.3/3.8L9-99

CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 1) are designed
to create high flow combustion chambers to improve
performance, while minimizing the change to the
burn rate in the chamber. The cylinder head incorpo-
rates the combustion chamber. Two valves per-cylin-
der are used with inserted valve seats and guides. A
multi-layer steel (MLS) type gasket is used between
the cylinder head and engine block.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
Fig. 1 Cylinder Head and Components
1 - VALVE LOCKS 5 - SPRING SEATS
2 - RETAINERS 6 - CYLINDER HEAD
3 - VALVE SPRINGS 7 - VALVE - EXHAUST
4 - VALVE STEM SEALS 8 - VALVE - INTAKE
9s - 16 ENGINE 3.3/3.8L SUPPLEMENTRS

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 - 20 FUEL INJECTIONRS
FUEL INJECTION (Continued)

O2 SENSOR
DESCRIPTION
The upstream oxygen sensor threads into the out-
let flange of the exhaust manifold (Fig. 22) or (Fig.
23).
The downstream heated oxygen sensor threads into
the outlet pipe at the rear of the catalytic convertor
(Fig. 24).
OPERATION
A seperate upstream and downstream grounds are
used on the NGC vehicles (4 Cyl.).
As vehicles accumulate mileage, the catalytic con-
vertor deteriorates. The deterioration results in aless efficient catalyst. To monitor catalytic convertor
deterioration, the fuel injection system uses two
heated oxygen sensors. One sensor upstream of the
catalytic convertor, one downstream of the convertor.
The PCM compares the reading from the sensors to
calculate the catalytic convertor oxygen storage
capacity and converter efficiency. Also, the PCM uses
the upstream heated oxygen sensor input when
adjusting injector pulse width.
When the catalytic converter efficiency drops below
emission standards, the PCM stores a diagnostic
trouble code and illuminates the malfunction indica-
tor lamp (MIL).
The O2 sensors produce a constant 2.5 volts on
NGC vehicles, depending upon the oxygen content of
the exhaust gas. When a large amount of oxygen is
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.
Fig. 22 O2 SENSOR UPSTREAM 1/1 - 2.4L
Fig. 23 O2 SENSOR UPSTREAM 1/1 - 3.3/3.8L
Fig. 24 O2 SENSOR DOWNSTREAM 1/2 - 2.4/3.3/
3.8L
14 - 32 FUEL INJECTIONRS

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 of
oxygen 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.
REMOVAL - UPSTREAM 1/1 - 3.3/3.8L
(1) Remove battery, refer to the Battery section for
more information.
(2) Remove the battery tray, refer to the Battery
section for more information.
(3) Disconnect the speed control vacuum harness
from servo.
(4) Disconnect the electrical connector from servo.
(5) Remove the speed control servo and bracket
and reposition.
(6) Use a socket such as the Snap-OntYA8875 or
equivalent to remove the sensor (Fig. 25).
(7) 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.
Fig. 25 O2 SENSOR 1/1
RSFUEL INJECTION14-33
O2 SENSOR (Continued)