
RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 19).
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 19) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
Fig. 17 WATER PUMP ASSEMBLY
1 - WATER PUMP HOUSING STUDS
2 - WATER PUMP
3 - RETAINING NUTS
4 - OIL COOLER RETAINING STUD
5 - OIL COOLER TO ENGINE BLOCK RETAINING BOLT
6 - OIL COOLER COOLANT HOSE
7 - ENGINE BLOCK
Fig. 18 WATER PUMP HOUSING O-RING
1 - WATER PUMP
2 - WATER PUMP HOUSING O-RING
3 - WATER PUMP HOUSING
Fig. 19 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - PRESSURE BOTTLE
8 - FILLER NECK
7a - 24 ENGINERG
WATER PUMP (Continued)

FASTEN SEAT BELT LAMP OR TONE CONTINUES
FOR MORE THAN 10 SECONDS AFTER SEAT
BELTS ARE FASTENED AND DRIVER'S DOOR IS
CLOSED.
Refer to the proper Body Diagnostic Procedures
manual.
NO TONE WHEN PARK OR HEADLAMPS ARE ON
AND DRIVER'S DOOR IS OPEN.
Make sure ignition is in lock position with the key
removed.
(1) Check the BCM DTC's and BCM sensors to
verify the door is open. Repair as necessary.
(2) Actuate Chime (BCM actuates).
(3) Inspect BCM connectors and wires for proper
connection.
(4) Measure with a voltmeter the voltage (12v) on
BCM connector (PX2) pin 34 with harness connected.
DIAGNOSIS AND TESTING - DOME LAMP ON
CHIME
The dome lamp on chime will warn the driver that
the dome lamps have been left on.
When the ignition is OFF:
²Driver's door OPEN (door ajar switch is closed to
ground) and
²Dome lamps are ON (dome lamp switch is closed
to ground),
The chime will sound continuously until driver's
door is closed, dome lamps tuned OFF or until the
battery protection time out of 15 minutes has
expired. Chime rate: 168 to 192 chimes per minute.
DIAGNOSIS AND TESTING - ENGINE
TEMPERATURE CRITICAL CHIME
The engine temperature critical chime will warn
the driver that the vehicle's engine is overheating.
While monitoring the coolant temperature, the Pow-
ertrain Control Module (PCM) will send on the PCI
data bus as engine temperature every 1.376 seconds
to the cluster. The MIC calculates engine tempera-
ture and determines if a warning should occur. This
feature is functional only with the Ignition Switch in
the Run/Start position.
When the engine temperature reaches 122ÉC
(252ÉF) the MIC requests a chime from the BCM and
the engine temperature lamp comes ON. The MIC
turns OFF the lamp when the engine temperature
reaches 117ÉC (242ÉF). The MIC will chime continu-
ously (request from the BCM). The chime will turn
OFF after four minutes or when the temperature
reaches 117ÉC (242ÉF), which ever occurs first.
DIAGNOSIS AND TESTING - EXTERIOR LAMPS
ON CHIME
The exterior lamp on chime will warn the driver
that the exterior lights have been left on.
With the ignition switch OFF/key out of ignition:
²Driver's door is open (door ajar switch is closed
to ground)
²Parking lamps or headlamps ON (parking lamp
switch is closed to ground)
The chime will sound until lights are turned OFF,
driver's door closed or until the battery protection
time out of 3 minutes has expired.
Chime rate: 168 to 192 chimes per minute.
To test the exterior lamps left on function:
²Turn ignition off
²Remove ignition key
²Turn exterior lamps on with driver's door open.
Chime should sound until lamps are turned off or
driver's door is closed.
DIAGNOSIS AND TESTING - KEY-IN IGNITION
CHIME
The key-in ignition chime will act as a warning to
the driver that the ignition key has been left in the
ignition switch.
With the ignition switch is in OFF position ONLY:
²Driver's door is open/ajar (door ajar switch is
closed to ground)
²Key is in the ignition switch (ignition is in the
LOCK position)
The chime will sound until one of the above condi-
tions is removed or until battery protection time out
(15 min.) has expired. Chime rate: 168 to 192 chimes
per minute.
To test the key-in ignition function, insert key into
the ignition and open driver's door. Do not turn igni-
tion ON. Chime should sound until key is removed
from ignition or driver's door is closed.
For diagnosis and testing of the Key-In Accessory
chime, use the same testing procedure as above but
with the key in the accessory position.
DIAGNOSIS AND TESTING - LOW OIL
PRESSURE CHIME
The low oil pressure chime will warn the driver
that the engine oil pressure is low. The oil pressure
switch will close to ground during a low oil pressure
condition. The oil pressure lamp will illuminate in
the message center. The PCM will monitor the oil
pressure switch and signal a low oil pressure condi-
tion. A continuous four minute warning chime will
sound and the oil pressure lamp will come ON when
the following conditions are met:
²Ignition on and engine not cranking
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)

OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
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.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL - CYLINDER HEAD
(1) Perform fuel system pressure release procedure
before attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - SPECIFICA-
TIONS)
(2) Disconnect battery negative cable.
(3) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(4) Remove air filter housing and inlet tube.
(5) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
Fig. 13 Cylinder Head and Camshafts
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
RSENGINE 2.4L9-23
CYLINDER HEAD (Continued)

CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 15) 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.
OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
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
Fig. 15 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
9 - 94 ENGINE 3.3/3.8LRS

FLUID
STANDARD PROCEDURE - FLUID LEVEL AND
CONDITION CHECK
NOTE: Only transmission fluid of the type labeled
Mopar ATF+4 (Automatic Transmission Fluid±Type
9602) should be used in this transaxle.
FLUID LEVEL CHECK
The transmission sump has a fluid level indicator
(dipstick) to check oil similar to most automatic
transmissions. It is located on the left side of the
engine. Be sure to wipe all dirt from dipstick handle
before removing.
The torque converter fills in both the P Park and N
Neutral positions. Place the selector lever in P Park
to be sure that the fluid level check is accurate.The
engine should be running at idle speed for at
least one minute, with the vehicle on level
ground.At normal operating temperature (approxi-
mately 82 C. or 180 F.), the fluid level is correct if it
is in the HOT region (cross-hatched area) on the oil
level indicator (Fig. 214). The fluid level should be
within the WARM range of the dipstick at 70É F fluid
temperature.
FLUID LEVEL CHECK USING DRB
NOTE: Engine and Transaxle should be at normal
operating temperature before performing this proce-
dure.
(1) Start engine and apply parking brake.
(2) Hook up DRB scan tool and select transmis-
sion.(3) Select sensors.
(4) Read the transmission temperature value.
(5) Compare the fluid temperature value with the
fluid temperature chart (Fig. 215).
(6) Adjust transmission fluid level shown on the
indicator according to the chart.
(7) Check transmission for leaks.
Low fluid level can cause a variety of conditions
because it allows the pump to take in air along with
the fluid. As in any hydraulic system, air bubbles
make the fluid spongy, therefore, pressures will be
low and build up slowly.
Improper filling can also raise the fluid level too
high. When the transaxle has too much fluid, the
gears churn up foam and cause the same conditions
which occur with a low fluid level.
In either case, air bubbles can cause overheating
and/or fluid oxidation, and varnishing. This can
interfere with normal valve, clutch, and accumulator
operation. Foaming can also result in fluid escaping
from the transaxle vent where it may be mistaken
for a leak.
FLUID CONDITION
Along with fluid level, it is important to check the
condition of the fluid. When the fluid smells burned,
and is contaminated with metal or friction material
particles, a complete transaxle recondition is proba-
bly required. Be sure to examine the fluid on the dip-
stick closely. If there is any doubt about its condition,
drain out a sample for a double check.
Moparž ATF+4 (Automatic Transmission Fluid-
Type 9602) when new is red in color. The ATF is dyed
red so it can be identified from other fluids used in
the vehicle such as engine oil or antifreeze. The red
color is not permanent and is not an indicator of fluid
condition. As the vehicle is driven, the ATF will begin
to look darker in color and may eventually become
brown. This is normal. A dark brown/black fluid
accompanied with a burnt odor and/or deterioration
in shift quality may indicate fluid deterioration or
transmission component failure.
After the fluid has been checked, seat the dipstick
fully to seal out water and dirt.
STANDARD PROCEDURE - FLUID AND FILTER
SERVICE
NOTE: Refer to the maintenance schedules in
LUBRICATION and MAINTENANCE, or the vehicle
owner's manual, for the recommended maintenance
(fluid/filter change) intervals for this transaxle.
Fig. 214 Transaxle Fluid Level Indicator
1 - TRANSAXLE DIPSTICK
21 - 246 AUTOMATIC - 41TERS

(2) Lubricate new rubber O-ring seals with clean
refrigerant oil and install them on the evaporator
tube fittings.
(3) Position the expansion valve onto the evapora-
tor tubes (Fig. 4).
(4) Install and tighten the two screws that secure
the expansion valve to the evaporator tube sealing
plate. Tighten the screws to 11 N´m (97 in. lbs.).
(5) If the vehicle is equipped with the optional
Automatic Temperature Control (ATC) system, recon-
nect the expansion valve solenoid pigtail wire connec-
tor to the rear HVAC wire harness connector for the
solenoid.
(6) Reinstall the rear evaporator line extension
onto the expansion valve. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - REAR/EVAPO-
RATOR - INSTALLATION - EVAPORATOR LINE
EXTENSION).
(7) Install the foam insulator wrap over the rear
expansion valve.
(8) Reinstall the rear heater-A/C unit housing into
the vehicle. (Refer to 24 - HEATING & AIR CONDI-
TIONING/DISTRIBUTION - REAR/REAR HEATER-
A/C HOUSING - INSTALLATION).
HEATER CORE
DESCRIPTION
The rear heater core is located near the front of
the rear heater-A/C unit housing, behind the right
rear wheel house. It is a heat exchanger made ofrows of tubes and fins. One end of the core is fitted
with a molded plastic tank that includes integral
heater core inlet and outlet nipples. The heater core
can be serviced without removing the rear heater-A/C
unit housing from the vehicle. The heater core cannot
be repaired and, if faulty or damaged, it must be
replaced.
OPERATION
Engine coolant is circulated through heater hoses
to the heater core at all times. As the coolant flows
through the heater core, heat removed from the
engine is transferred to the heater core fins and
tubes. Air directed through the heater core picks up
the heat from the heater core fins. The blend air door
allows control of the heater output air temperature
by controlling how much of the air flowing through
the rear heater-A/C unit housing is directed through
the heater core.
STANDARD PROCEDURE - HEATER CORE
FILLING
In its final installed position, the rear heater core
is positioned higher than the radiator fill cap. There-
fore, when the cooling system is drained and refilled,
gravity will not refill the heater core with coolant to
the proper level. This may result in two problems:1.
Insufficient coolant level in the engine cooling sys-
tem, which may result in engine overheating.2.Air
entrapped within the rear heater core, which may
result in insufficient rear heater performance. There
are two methods that may be employed to prevent
these problems:1.Pre-filling of the rear heater core.
2.Thermal cycling of the engine cooling system. Fol-
lowing are descriptions of both prevention methods,
as well as a method to verify rear heater perfor-
mance.
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 - HEATER PLUMB-
ING).
PRE-FILLING
If the rear heater core or the rear heater-A/C hous-
ing have been removed from the vehicle for service,
the rear heater core may be pre-filled with the proper
engine coolant mixture prior to reconnecting the
heater hoses to the heater core hose fittings.
(1) The heater core should be installed in the rear
heater-A/C unit housing, and the rear heater-A/C
unit housing should be installed in the vehicle.
Fig. 4 Expansion Valve
1 - SOLENOID
2 - SOLENOID CONNECTOR
3 - SEALING PLATE
4 - EXPANSION VALVE
5 - SEALING PLATE
6 - HVAC CONNECTOR
24 - 100 PLUMBING - REARRS
EXPANSION VALVE (Continued)

Symptom:
P0420-1/1 CATALYTIC CONVERTER EFFICIENCY
When Monitored and Set Condition:
P0420-1/1 CATALYTIC CONVERTER EFFICIENCY
When Monitored: After engine warm up to 70ÉC (158ÉF), 180 seconds of open throttle
operation, at a speed greater than 18 mph and less than 55 mph, with the engine at
1200-1700 rpm and MAP vacuum between 15.0 and 21.0 inches of mercury (Hg).
Set Condition: As catalyst efficiency deteriorates, the switch rate of the downstream O2
sensor approaches that of the upstream O2 sensor. If at any point during the test the
switch ratio reaches a predetermined value a counter is incremented by one.
POSSIBLE CAUSES
INTERMITTENT CONDITION
VISUALLY INSPECT CATALYTIC CONVERTER
EXHAUST LEAK
ENGINE MECHANICAL CONDITION
AGING O2 SENSOR
CATALYTIC CONVERTER
TEST ACTION APPLICABILITY
1NOTE: If a O2 Sensor DTC(s) set along with the Catalytic Converter
Efficiency DTC diagnose the O2 Sensor DTC(s) before continuing.
NOTE: Check for contaminates that may have damaged the O2 Sensor and
Catalytic Converter: contaminated fuel, unapproved silicone, oil and cool-
ant, repair necessary.
Turn the ignition on.
With the DRBIIIt, read DTC's.
Is the Good Trip displayed and equal to zero?All
Ye s®Go To 2
No®Go To 7
2 Inspect the Catalytic Converter for the following damage.
Damage Catalytic Converter, dent and holes.
Severe discoloration caused by overheating the Catalytic Converter.
Catalytic Converter broke internally.
Leaking Catalytic Converter.
Were any problems found?All
Ye s®Replace the Catalytic Converter. Repair the condition that may
have caused the failure.
Perform POWERTRAIN VERIFICATION TEST VER - 5.
No®Go To 3
131
DRIVEABILITY - GAS

4.3 WARNINGS
4.3.1 VEHICLE DAMAGE WARNINGS
Before disconnecting any control module, make
sure the ignition is ªoffº. Failure to do so could
damage the module.
When testing voltage or continuity at any control
module, use the terminal side (not the wire end) of
the connector. Do not probe a wire through the
insulation; this will damage it and eventually cause
it to fail because of corrosion.
Be careful when performing electrical tests so as
to prevent accidental shorting of terminals. Such
mistakes can damage fuses or components. Also, a
second code could be set, making diagnosis of the
original problem more difficult.
4.3.2 ROAD TEST COMPLAINT VEHICLE
Some complaints will require a test drive as part
of the repair verification procedure. The purpose of
the test drive is to try to duplicate the diagnostic
code or symptom condition.
CAUTION: BEFORE ROAD TESTING A
VEHICLE, BE SURE THAT ALL
COMPONENTS ARE REASSEMBLED.
DURING THE TEST DRIVE, DO NOT TRY TO
READ THE DRBIIITSCREEN WHILE IN
MOTION. DO NOT HANG THE DRBIIITFROM
THE REAR VIEW MIRROR OR OPERATE IT
YOURSELF. HAVE AN ASSISTANT
AVAILABLE TO OPERATE THE DRBIIIT.
Road testing is an essential step in the diagnostic
process that must not be overlooked. Along with
diagnostic information obtained from the DRBIIIt
Scan Tool and the original customer concern, the
road test helps to verify the problem and observe
operation under actual vehicle driving conditions.
Just as important as the road test is, there are
preliminary inspections that should be carried out
prior to the road test. Always check the fluid level
and condition before going on a road test or per-
forming other tests. Also try to determine the type
of fluid being used. Improper fluid can result in
problems. Additionally, a variety of complaints can
be caused by incorrect fluid level. Some of the
conditions caused by incorrect fluid level are as
follows:
²Delayed engagement
²Poor shifting or erratic shifts
²Excessive noise
²Overheating
The next step is to verify that the shift linkage is
correctly adjusted. If the gearshift linkage is incor-rectly adjusted because of wear or incorrect adjust-
ment, a number of complaints can result.
The TCM monitors the Shift Lever Position (SLP)
Sensor at all times. If the linkage is incorrectly
adjusted, the TCM may sense a shift lever position
that is not correct for the gear range chosen by the
driver. This may cause diagnostic trouble codes to
be set and a possible limp-in situation.
The following complaints may also be the result
of an incorrectly adjusted or worn linkage.
²Delayed clutch engagement or erratic shifts
²Vehicle able to drive in Neutral
²Engine not able to crank in Park or Neutral
²Gearshift linkage able to be shifted without the
key in the ignition
²Not able to remove the ignition key in Reverse
²Parking pawl not engaging
The shift linkage should also be adjusted when
replacing the transaxle, repairing the valve body or
repairing any component between the shift lever
and the transaxle.
Some questions to ask yourself when considering
the road test are listed below:
²Is the complaint or concern what you think it is,
based the driver 's description of the problem?
²Is the transaxle operating normally, or is there a
real problem?
²When does the malfunction occur?
²Is the problem in only one gear range?
²What temperature does the complaint occur?
²Is the transaxle in limp-in mode?
4.3.3 ELECTRONIC PINION FACTOR
WARNINGS
The pinion factor must be set for all new trans-
mission control modules. If the pinion factor is not
set or if it is set incorrectly, any speedometer, speed
control, rolling door locks, and other devices that
are operated by the powertrain and body controllers
will not function properly.
4.3.4 BULLETINS AND RECALLS
The service procedures contained in this manual
are correct. provided that all applicable Safety
Recalls and Technical Service Bulletins have been
performed.
5.0 REQUIRED TOOLS AND
EQUIPMENT
> DRBIIIt(diagnostic read-out box) - Must be at
latest release level.
20
GENERAL INFORMATION