oil temperature DODGE TOWN AND COUNTRY 2003 User Guide

CONDITION POSSIBLE CAUSES CORRECTION
3. Obstructions in heater hose
fitting at engine or at heater core.3. Remove heater hoses at both
ends and check for obstructions.
Repair as necessary.
4. Heater hose kinked. 4. Locate kinked area and repair as
necessary.
5. Water pump is not pumping
coolant to heater core.5. When the engine is fully warmed
up, both heater hoses should be hot
to the touch. If only one of the
hoses is hot, the water pump may
not be operating correctly. Replace
components as necessary.
6. Air trapped in heater core. 6. (Refer to 7 - COOLING -
DIAGNOSIS AND TESTING -
COOLING SYSTEM DEAERATION)
HEAT ODOR 1. Various heat shields are used at
certain driveline components. One
or more of these shields may be
missing.1. Locate missing shields and
replace or repair as necessary.
2. Temperature gauge reading
above the normal range.2. Refer to Gauge Is Reading High
in Temperature Gauge Indicatication
Diagnosis Chart.
3. Radiator fan operating
incorrectly.3. (Refer to 7 - COOLING/ENGINE/
RADIATOR FAN - OPERATION)
Repair as necessary.
4. Undercoating been applied to an
unnecessary component.4. Clean undercoating as necessary.
5. Engine may be running rich,
causing the catalytic converter to
overheat5. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
POOR DRIVEABILITY
(THERMOSTAT POSSIBLY STUCK
OPEN). GAUGE MAY BE READING
LOW.1. The engine thermostat must be
operating correctly for proper
driveability, clean vehicle emissions,
and the prevention of sludge
buildup in the engine oil. Check for
a diagnostic trouble code.1. (Refer to Appropriate Diagnostic
Information) Replace thermostat, if
necessary.
STEAM IS COMING FROM FRONT
OF VEHICLE NEAR GRILL AREA
WHEN WEATHER IS WET,
ENGINE WARMED UP AND
RUNNING WITH VEHICLE
STATIONARY, OR JUST SHUT
OFF. TEMPERATURE GAUGE IS
NORMAL.1. During wet weather, moisture
(snow, ice, rain, or condensation)
on the radiator will evaporate when
the thermostat opens. The
thermostat opening allows heated
coolant into the radiator. When the
moisture contacts the hot radiator,
steam may be emitted. This usually
occurs in cold weather with no fan
or air flow to blow it away.1. Occasional steam emitting from
this area is normal. No repair is
necessary.
7 - 16 ENGINERS
ENGINE (Continued)
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COOLANT
DESCRIPTION - ENGINE COOLANT
WARNING: ANTIFREEZE IS AN ETHYLENE GLYCOL
BASE COOLANT AND IS HARMFUL IF SWAL-
LOWED OR INHALED. IF SWALLOWED, DRINK
TWO GLASSES OF WATER AND INDUCE VOMIT-
ING. IF INHALED, MOVE TO FRESH AIR AREA.
SEEK MEDICAL ATTENTION IMMEDIATELY. DO NOT
STORE IN OPEN OR UNMARKED CONTAINERS.
WASH SKIN AND CLOTHING THOROUGHLY AFTER
COMING IN CONTACT WITH ETHYLENE GLYCOL.
KEEP OUT OF REACH OF CHILDREN. DISPOSE OF
GLYCOL BASE COOLANT PROPERLY, CONTACT
YOUR DEALER OR GOVERNMENT AGENCY FOR
LOCATION OF COLLECTION CENTER IN YOUR
AREA. DO NOT OPEN A COOLING SYSTEM WHEN
THE ENGINE IS AT OPERATING TEMPERATURE OR
HOT UNDER PRESSURE, PERSONAL INJURY CAN
RESULT. AVOID RADIATOR COOLING FAN WHEN
ENGINE COMPARTMENT RELATED SERVICE IS
PERFORMED, PERSONAL INJURY CAN RESULT.
CAUTION: Use of Propylene Glycol based coolants
is not recommended, as they provide less freeze
protection and less boiling protection.
The cooling system is designed around the coolant.
The coolant must accept heat from engine metal, in
the cylinder head area near the exhaust valves and
engine block. Then coolant carries the heat to the
radiator where the tube/fin radiator can transfer the
heat to the air.
The use of aluminum cylinder blocks, cylinder
heads, and water pumps requires special corrosion
protection. MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769), or the equiva-
lent ethylene glycol base coolant with hybrid organic
corrosion inhibitors (called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% Ethylene Glycol and 50% distilled
water to obtain a freeze point of -37ÉC (-35ÉF). If it
loses color or becomes contaminated, drain, flush,
and replace with fresh properly mixed coolant solu-
tion.
The green coolantMUST NOT BE MIXEDwith
the orange or magenta coolants. When replacing cool-
ant the complete system flush must be performed
before using the replacement coolant.
CAUTION: MoparTAntifreeze/Coolant, 5
Year/100,000 Mile Formula (MS-9769) may not be
mixed with any other type of antifreeze. Doing so
will reduce the corrosion protection and may resultin premature water pump seal failure. If non-HOAT
coolant is introduced into the cooling system in an
emergency, it should be replaced with the specified
coolant as soon as possible.DIAGNOSIS AND TESTING - COOLANT
CONCENTRATION TESTING
Coolant concentration should be checked when any
additional coolant was added to system or after a
coolant drain, flush and refill. The coolant mixture
offers optimum engine cooling and protection against
corrosion when mixed to a freeze point of -37ÉC
(-34ÉF) to -46ÉC (-50ÉF). The use of a hydrometer or a
refractometer can be used to test coolant concentra-
tion.
A hydrometer will test the amount of glycol in a
mixture by measuring the specific gravity of the mix-
ture. The higher the concentration of ethylene glycol,
the larger the number of balls that will float, and
higher the freeze protection (up to a maximum of
60% by volume glycol).
A refractometer (Special Tool 8286)(Refer to 7 -
COOLING - SPECIAL TOOLS) will test the amount
of glycol in a coolant mixture by measuring the
amount a beam of light bends as it passes through
the fluid.
Some coolant manufactures use other types of gly-
cols into their coolant formulations. Propylene glycol
is the most common new coolant. However, propylene
glycol based coolants do not provide the same freez-
ing protection and corrosion protection and is not rec-
ommended.
CAUTION: Do not mix types of coolantÐcorrosion
protection will be severely reduced.
STANDARD PROCEDURE - COOLANT SERVICE
For engine coolant recommended service schedule,
(Refer to LUBRICATION & MAINTENANCE/MAIN-
TENANCE SCHEDULES - DESCRIPTION).
COOLANT RECOVERY
CONTAINER
DESCRIPTION
The coolant recovery/reserve system container is
mounted in the engine compartment (Fig. 2). The
container is made of plastic.
OPERATION
The coolant recovery system works with the radia-
tor pressure cap to use thermal expansion and con-
traction of the coolant to keep the coolant free of
trapped air. Provides a convenient and safe method
RSENGINE7-19
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for checking coolant level and adjusting level at
atmospheric pressure without removing the radiator
pressure cap. It also provides some reserve coolant to
cover deaeration, evaporation, or boiling losses.
DIAGNOSIS AND TESTING - COOLANT
RECOVERY SYSTEM
The cooling system is closed and designed to main-
tain coolant level to the top of the radiator.
(1) With the engineoffand cooling systemnot
under pressure, drain several ounces of coolant from
the radiator draincock while observing the coolant
recovery container. Coolant level in the container
should drop.
(2) Remove the radiator pressure cap. The coolant
level should be full to the top radiator neck. If not,
and the coolant level in the container is at or above
the MIN mark, there is an air leak in the coolant
recovery system.
(3) Check hose and hose connections to the con-
tainer, radiator filler neck or the pressure cap seal to
the radiator filler neck for leaks.
REMOVAL
(1) Raise the vehicle on hoist.
(2) Remove the lower attaching screws (Fig. 2).
(3) Lower the vehicle.
(4) Remove the upper attaching screw (Fig. 2).
(5) Disconnect recovery hose from container (Fig.
2).
(6) Remove the recovery container.
INSTALLATION
(1) Connect the recovery hose to container (Fig. 2).
(2) Position the recovery container on the frame
rail (Fig. 2).
(3) Install the upper attaching screw and tighten
to 7 N´m (60 in. lbs.) (Fig. 2).
(4) Raise the vehicle on hoist.
(5) Install the lower attaching screws and tighten
to 8.5 N´m (75 in. lbs.) (Fig. 2).
(6) Lower the vehicle.
(7) Add coolant to container as necessary. (Refer to
7 - COOLING - STANDARD PROCEDURE)
ENGINE BLOCK HEATER
DESCRIPTION
The engine block heater is available as an optional
accessory on all models. The heater is operated by
ordinary house current (110 Volt A.C.) through a
power cord located behind the radiator grille. This
provides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures. The heater is mounted in a core
hole (in place of a core hole plug) in the engine block,
with the heating element immersed in coolant.
OPERATION
The block heater element is submerged in the cool-
ing system's coolant. When electrical power (110 volt
A.C.) is applied to the element, it creates heat. This
heat is transferred to the engine coolant. This pro-
vides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures.
DIAGNOSIS AND TESTING - ENGINE BLOCK
HEATER TESTING
If unit does not operate, trouble can be in either
the power cord or the heater element. Test power
cord for continuity with a 110-volt voltmeter or 110-
volt test light; test heater element continuity with an
ohmmeter or 12-volt test light.
REMOVAL
(1) Drain coolant from radiator and cylinder block.
(Refer to 7 - COOLING - STANDARD PROCEDURE)
(2) Disconnect the power cord plug from heater.
(3) Loosen screw in center of heater. Remove the
heater assembly.
INSTALLATION
(1) Clean block core hole and heater seat.
(2) Insert heater assembly with element loop posi-
tionedupward.
Fig. 2 Coolant Recovery Container
1 - UPPER BOLT ATTACHING TO BATTERY TRAY
2 - COOLANT RECOVERY CONTAINER
3 - UPPER BOLT
4 - HOSE
5 - LOWER BOLT (QTY. 2)
6 - LEFT SIDE FRAME RAIL
7 - 20 ENGINERS
COOLANT RECOVERY CONTAINER (Continued)
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(3) With heater seated, tighten center screw
securely to assure a positive seal.
(4) Install power cord plug to heater.
(5) Fill cooling system with coolant to the proper
level. (Refer to 7 - COOLING - STANDARD PROCE-
DURE)
ENGINE COOLANT
TEMPERATURE SENSOR - 2.4L
DESCRIPTION
The engine coolant temperature sensor threads
into the top of the thermostat housing (Fig. 3). New
sensors have sealant applied to the threads.
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Drain the cooling system below thermostat
level. (Refer to 7 - COOLING - STANDARD PROCE-
DURE)
(2) Disconnect coolant temperature sensor electri-
cal connector.
(3) Remove coolant temperature sensor (Fig. 3).
INSTALLATION
(1) Install coolant temperature sensor (Fig. 3).
Tighten sensor to 7 N´m (60 in. lbs.).
(2) Connect electrical connector to sensor.
(3) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
ENGINE COOLANT
TEMPERATURE SENSOR -
3.3/3.8L
DESCRIPTION
The engine coolant temperature sensor threads
into a coolant passage on lower intake manifold near
the thermostat (Fig. 6). New sensors have sealant
applied to the threads.
REMOVAL
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING. COOLING SYSTEM
MUST BE PARTIALLY DRAINED BEFORE REMOV-
ING THE COOLANT TEMPERATURE SENSOR.
(1) Drain cooling system below engine coolant tem-
perature sensor level. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(2) Remove power steering reservoir and relocate
(Fig. 4). Do not disconnect hoses.
Fig. 3 Engine Coolant Temperature Sensor - 2.4L
1 - MAP SENSOR
2 - COOLANT TEMPERATURE SENSORFig. 4 Power Steering Fluid Reservoir
1 - POWER STEERING RESERVOIR
2 - BOLT - RESERVOIR TO MANIFOLD
3 - NUT - RESERVOIR TO COIL BRACKET
RSENGINE7-21
ENGINE BLOCK HEATER (Continued)
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(3) Remove ignition coil and bracket (Fig. 5).
(4) Disconnect coolant sensor electrical connector
(Fig. 6).
(5) Remove coolant sensor (Fig. 6).
INSTALLATION
(1) Install engine coolant temperature sensor (Fig.
6). Tighten sensor to 7 N´m (60 in. lbs.).
(2) Connect electrical connector to sensor (Fig. 6).
(3) Install ignition coil bracket (Fig. 5).
(4) Install ignition coil (Fig. 5).
(5) Install power steering reservoir (Fig. 4).
(6) Fill cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
ENGINE COOLANT
THERMOSTAT
DESCRIPTION
The engine cooling thermostats are a wax pellet
driven, reverse poppet choke type. The thermostat is
mounted in a housing on the coolant outlet of the
engine (Fig. 8) or (Fig. 10).
OPERATION
The engine cooling thermostat is a wax pellet
driven, reverse poppet choke type. The thermostat is
designed to provide the fastest warm up possible by
preventing leakage through it and to guarantee a
minimum engine operating temperature of 88 to
93ÉC (192 to 199ÉF). The thermostat also will auto-
matically reach wide open so it will not restrict flow
to the radiator as temperature of the coolant rises in
hot weather to around 104ÉC (220ÉF). Above this
temperature the coolant temperature is controlled by
the radiator, fan, and ambient temperature, not the
thermostat.
The thermostat is operated by a wax filled con-
tainer (pellet) which is sealed. When heated coolant
reaches a predetermined temperature, the wax
expands enough to overcome the closing spring and
water pump pressure, which forces the valve to open.
Fig. 5 Fuel Rail, Ignition Coil and Bracket
1 - FUEL RAIL
2 - BOLT - FUEL RAIL
3 - NUT - IGNITION COIL
4 - BOLT - IGNITION COIL
5 - IGNITION COIL
6 - BRACKET - IGNITION COIL
7 - STUD - IGNITION COIL
8 - SEPARATOR - SPARK PLUG CABLE
9 - BRACKET - SPARK PLUG CABLE SEPARATOR
10 - BOLT - SEPARATOR BRACKET
11 - BRACKET - SPARK PLUG CABLE SEPARATOR
Fig. 6 Engine Coolant Temperature Sensor
1 - ENGINE COOLANT TEMPERATURE SENSOR
2 - CONNECTOR - ENGINE COOLANT SENSOR
3 - FITTING - HEATER SUPPLY
7 - 22 ENGINERS
ENGINE COOLANT TEMPERATURE SENSOR - 3.3/3.8L (Continued)
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OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE A/C PRESSURE TRANSAXLE OIL
TEMPERATURE
Fan
Operation
Speeds:Initial Max Initial Max Initial Max
Fan On: 104ÉC
(220ÉF)110ÉC
(230ÉF) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%1,724 Kpa
(250 psi)2,068 Kpa
(300 psi) Fan
Speed
Duty-Cycles
(Ramps-up)
from 30% to
99%96ÉC (204ÉF) 111ÉC (232ÉF)
Fan Speed
Duty Cycles
(Ramps-up)
from 30% to
99%
Fan Off: 101ÉC
(214ÉF)Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%1,710 Kpa
(248 psi)Fan Speed
Duty-Cycles
(Ramps-
down) from
99% to 30%89ÉC (192ÉF) Fan Speed
Duty Cycles
(Ramps-down)
from 99% to
30%
DIAGNOSIS AND TESTING - RADIATOR FAN MOTOR
RADIATOR FAN DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY RADIATOR FAN 1. Fan blade loose. 1. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
2. Fan blade striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or A/C
condenser.3. Remove obstructions and/or
clean debris.
4. Electric fan motor defective. 4. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
ELECTRIC FAN MOTOR DOES
NOT OPERATE1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor, or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Defective A/C pressure
transducer.2. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
ELECTRIC RADIATOR FAN
OPERATES ALL THE TIME1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Check for low coolant level. 2. Add coolant as necessary.
3. Defective A/C pressure
transducer.3. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
RSENGINE7-29
RADIATOR FAN (Continued)
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REMOVAL
There are no repairs to be made to the fan or
shroud assembly. If the fan is warped, cracked, or
otherwise damaged, it must be replaced as an assem-
bly (Fig. 21).
(1) Remove the radiator upper crossmember. (Refer
to 23 - BODY/EXTERIOR/GRILLE OPENING REIN-
FORCEMENT - REMOVAL)
(2) Disconnect the radiator fan electrical connec-
tors.
(3) Remove radiator fan(s) retaining screw (Fig.
21).
(4) Remove the radiator fan(s) by lifting upward to
release from mounts.
INSTALLATION
(1) Install the radiator fan(s) into mounts and
attaching clips on the radiator.
(2) Install radiator fan(s) attaching screws (Fig.
21). Tighten to 5 N´m (45 in. lbs.).
(3) Connect the radiator fan(s) electrical connec-
tors.
(4) Install the radiator upper support crossmem-
ber. (Refer to 23 - BODY/EXTERIOR/GRILLE OPEN-
ING REINFORCEMENT - INSTALLATION)
(5) Install the upper radiator mounts to the cross-
member bolts, if removed. Tighten to 8 N´m (70 in.
lbs.).
(6) Install the radiator upper hose to the support
clip (2.4L engine).
RADIATOR FAN RELAY
DESCRIPTION
The radiator fan relay is a solid state type and is
located on the front bumper reinforcment (Fig. 22).
Refer to WIRING DIAGRAMS for a circuit sche-
matic.
OPERATION
The solid state radiator fan relay is controlled by
the Powertrain Control Module (PCM) by way of a
Pulse Width Modulated (PWM) signal. The relay con-
trol circuit supplies a 12 volt signal to the PCM. The
PCM then pulses the ground circuit to achieve fan on
time. The relay provides a voltage to the fan motors
which is proportional to the pulse width it receives
from the PCM. The duty cycle ranges from 30% for
low speed operation, then ramps-up to 100% for high
speed operation. This fan control system provides
infinitely variable fan speeds, allowing for improved
fan noise, A/C performance, better engine cooling,
and additional vehicle power.
To control operation of the relay, the PCM looks at
inputs from:
²Engine coolant temperature
²A/C pressure transducer
²Ambient temperature from the body controller
²Vehicle speed
²Transmission oil temperature
The PCM uses these inputs to determine when the
fan should operate and at what speed. For further
information on fan operation, (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - OPERATION).
REMOVAL
(1) Open hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the radiator crossmember to front fas-
cia closure panel.
(4) Disconnect the relay electrical connector (Fig.
22).
(5) Remove the rivet attaching the relay to the
front bumper beam (Fig. 22).
(6) Remove the relay.
INSTALLATION
CAUTION: The relay mounting location is designed
to dissipate heat. Ensure the relay is securely
attached to prevent relay ªthermalº shutdown and
relay damage, resulting in possible engine over-
heating.
(1) Position relay and install a new rivet (Fig. 22).
(2) Connect electrical connector to relay.
Fig. 21 Radiator Fans
1 - SCREWS - RADIATOR FAN ATTACHING
2 - RADIATOR FAN - RIGHT
3 - MOUNT - RIGHT RADIATOR FAN
4 - CLIPS - RADIATOR FAN LOWER
5 - MOUNT - LEFT RADIATOR FAN
6 - RADIATOR FAN - LEFT
7 - 30 ENGINERS
RADIATOR FAN (Continued)
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CHIME/BUZZER
TABLE OF CONTENTS
page page
CHIME/BUZZER
DESCRIPTION..........................1
OPERATION............................1WARNING.............................1
DIAGNOSIS AND TESTING - CHIME SYSTEM . . 1
CHIME/BUZZER
DESCRIPTION
The chime/buzzer system provides the driver with
warning chimes for:
²Seat Belt
²Exterior Lamps ON
²Key-In Ignition
²Engine Temperature Critical
²Turn Signals ON
²Dome Lamp ON
²Low Oil Pressure
²High Speed Warning
²Warning Lamp Announcement
²Key-In Accessory
²Low/High Tire Pressure
²Service Tire Pressure Monitor (TPM)
HIGH SPEED WARNING - EXPORT
The chime will sound, acting as a warning to the
driver that the vehicle speed has exceeded 120   3
kph (75   2 mph).
Refer to the proper Body Diagnostic Procedures
manual for further description of chimes.
OPERATION
Refer to the proper Body Diagnostic Procedures
manual for complete chime/buzzer operation and con-
ditions for operation.
HIGH SPEED WARNING - EXPORT
When the vehicle speed sensor sees 120 3kph
(75   2 mph), it sends a PCI data bus message to the
Body Control Module (BCM). The BCM then turns on
the chime to let the driver know that the vehicle has
reached a speed greater than 120 3kph(75 2
mph). This audible message will continue until the
vehicle is slowed below the predetermined speed.
WARNING
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
DIAGNOSIS AND TESTING - CHIME SYSTEM
Refer to the proper Body Diagnostic Procedures
manual for complete Diagnosis and Testing of the
Chime System.
NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER'S SEAT BELT IS NOT BUCKLED.
(1) Using a DRB llltscan tool, actuate chime
(BCM actuates).
(2) Using a voltmeter, check for voltage:
(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
RSCHIME/BUZZER8B-1
ProCarManuals.com

NOTE: PCM Inputs:
²Air Conditioning Pressure Transducer
²Ambient temperature Sensor
²ASD Relay
²Battery Temperature Sensor (NGC)
²Battery Voltage
²Brake Switch
²Camshaft Position Sensor
²Crankshaft Position Sensor
²Distance Sensor (from transmission control mod-
ule)
²EGR Position Feedback
²Engine Coolant Temperature Sensor
²Heated Oxygen Sensors
²Ignition sense
²Intake Air Temperature Sensor
²Knock Sensor
²Leak Detection Pump Feedback
²Manifold Absolute Pressure (MAP) Sensor
²Park/Neutral
²PCI Bus
²Power Steering Pressure Switch
²Proportional Purge Sense
²SCI Receive
²Speed Control
²Throttle Position Sensor
²Torque Management Input
²Transaxle Control Module (3.3/3.8L Only)
²Transmission Control Relay (Switched B+) (2.4L
Only)
²Transmission Pressure Switches (2.4L Only)
²Transmission Temperature Sensor (2.4L Only)
²Transmission Input Shaft Speed Sensor (2.4L
Only)
²Transmission Output Shaft Speed Sensor (2.4L
Only)
²Transaxle Gear Engagement
²Vehicle Speed
NOTE: PCM Outputs:
²Air Conditioning Clutch Relay
²Automatic Shut Down (ASD) and Fuel Pump
Relays
²Data Link Connector (PCI and SCI Transmit)
²Double Start Override
²EGR Solenoid
²Fuel Injectors
²Generator Field
²High Speed Fan Relay
²Idle Air Control Motor
²Ignition Coils
²Leak Detection Pump
²Low Speed Fan Relay
²MTV Actuator
²Proportional Purge Solenoid²SRV Valve
²Speed Control Relay
²Speed Control Vent Relay
²Speed Control Vacuum Relay
²8 Volt Output
²5 Volt Output
²Torque Reduction Request
²Transmission Control Relay (2.4L Only)
²Transmission Solenoids (2.4L Only)
²Vehicle Speed
Based on inputs it receives, the powertrain control
module (PCM) adjusts fuel injector pulse width, idle
speed, ignition timing, and canister purge operation.
The PCM regulates the cooling fans, air conditioning
and speed control systems. The PCM changes gener-
ator charge rate by adjusting the generator field.
The PCM adjusts injector pulse width (air-fuel
ratio) based on the following inputs.
²Battery Voltage
²Intake Air Temperature Sensor
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Exhaust Gas Oxygen Content (heated oxygen
sensors)
²Manifold Absolute Pressure
²Throttle Position
The PCM adjusts engine idle speed through the
idle air control motor based on the following inputs.
²Brake Switch
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Park/Neutral
²Transaxle Gear Engagement
²Throttle Position
²Vehicle Speed
The PCM adjusts ignition timing based on the fol-
lowing inputs.
²Intake Air Temperature
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Knock Sensor
²Manifold Absolute Pressure
²Park/Neutral
²Transaxle Gear Engagement
²Throttle Position
The automatic shut down (ASD) and fuel pump
relays are mounted externally, but turned on and off
by the powertrain control module through the same
circuit.
The camshaft and crankshaft signals are sent to
the powertrain control module. If the PCM does not
receive both signals within approximately one second
of engine cranking, it deactivates the ASD and fuel
pump relays. When these relays are deactivated,
power is shut off to the fuel injectors, ignition coils,
8E - 12 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
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fuel pump and the heating element in each oxygen
sensor.
The PCM contains a voltage converter that
changes battery voltage to a regulated 8.0 volts. The
8.0 volts power the camshaft position sensor, crank-
shaft position sensor and vehicle speed sensor. The
PCM also provides a 5.0 volts supply for the engine
coolant temperature sensor, intake air temperature
sensor, manifold absolute pressure sensor and throt-
tle position sensor.
The PCM engine control strategy prevents reduced
idle speeds until after the engine operates for 320 km
(200 miles). If the PCM is replaced after 320 km (200
miles) of usage, update the mileage in new PCM. Use
the DRBIIItscan tool to change the mileage in the
PCM. Refer to the appropriate Powertrain Diagnostic
Manual and the DRBIIItscan tool.
TRANSMISSION CONTROL (2.4L MODELS ONLY)
CLUTCH VOLUME INDEX (CVI)
An important function of the PCM is to monitor
Clutch Volume Index (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.
The PCM monitors gear ratio changes by monitor-
ing the Input and Output Speed Sensors. The Input,
or Turbine Speed Sensor sends an electrical signal to
the PCM that represents input shaft rpm. The Out-
put Speed Sensor provides the PCM with output
shaft speed information.
By comparing the two inputs, the PCM can deter-
mine transaxle gear ratio. This is important to the
CVI calculation because the PCM determines CVIs
by monitoring how long it takes for a gear change to
occur (Fig. 10).
Gear ratios can be determined by using the DRB
Scan Tool and reading the Input/Output Speed Sen-
sor values in the ªMonitorsº display. Gear ratio can
be obtained by dividing the Input Speed Sensor value
by the Output Speed Sensor value.
For example, if the input shaft is rotating at 1000
rpm and the output shaft is rotating at 500 rpm,
then the PCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changesto 1:1. The gear ratio changes as clutches are applied
and released. By monitoring the length of time it
takes for the gear ratio to change following a shift
request, the PCM can determine the volume of fluid
used to apply or release a friction element.
The volume of transmission fluid needed to apply
the friction elements are continuously updated for
adaptive controls. As friction material wears, the vol-
ume of fluid need to apply the element increases.
Certain mechanical problems within the clutch
assemblies (broken return springs, out of position
snap rings, excessive clutch pack clearance, improper
assembly, etc.) can cause inadequate or out-of-range
clutch volumes. Also, defective Input/Output Speed
Sensors and wiring can cause these conditions. The
following chart identifies the appropriate clutch vol-
umes and when they are monitored/updated:
CLUTCH VOLUMES
ClutchWhen Updated
Proper Clutch
Volume
Shift Sequence Oil Temperature Throttle Angle
L/R2-1 or 3-1 coast
downshift>70É <5É 35to83
2/4 1-2 shift
> 110É5 - 54É20 to 77
OD 2-3 shift 48 to 150
UD 4-3 or 4-2 shift > 5É 24 to 70
Fig. 10 Example of CVI Calculation
1 - OUTPUT SPEED SENSOR
2 - OUTPUT SHAFT
3 - CLUTCH PACK
4 - SEPARATOR PLATE
5 - FRICTION DISCS
6 - INPUT SHAFT
7 - INPUT SPEED SENSOR
8 - PISTON AND SEAL
RSELECTRONIC CONTROL MODULES8E-13
POWERTRAIN CONTROL MODULE (Continued)
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