oil change DODGE TOWN AND COUNTRY 2003 Owner's Manual

SCHEDULE ªAº
Kilometers 20 000 km 40 000 km 60 000 km 80 000 km 100 000 km
Change engine oil and engine oil filter.XXXX X
Inspect engine air filter element. Replace
as necessary.XX X
Replace engine air filter element X X
Replace fuel filter/water separator unit.XXXX X
Replace engine timing belt.X
Check front end alignment. X X
Inspect the tie rod ends and boot seals. X X
Inspect the brake linings.XXXX X
Kilometers 120 000 km 140 000 km 160 000 km 180 000 km
Change engine oil and engine oil filter. X X X X
Inspect engine air filter element. Replace as
necessary.XX
Inspect accessory drive belts and replace if
necessary.X
Replace engine air filter element X X
Replace fuel filter/water separator unit. X X X X
Flush and replace engine coolant. X
Check front end alignment. X X
Inspect the tie rod ends and boot seals. X X
Inspect the brake linings. X X X X
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
Retain all receipts.
WARNING: You can be badly injured working on or
around a motor vehicle. Do only that service work
for which you have the knowledge and the rightequipment. If you have any doubt about your ability
to perform a service job, take your vehicle to a
competent mechanic.
RSMAINTENANCE SCHEDULES0a-11
MAINTENANCE SCHEDULES FOR ALL MARKETS EXCEPT U.S., CANADA and MEXICO (Continued)
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(3) Check position of the stabilizer bar in the front
suspension cradle. The center of the curved section of
the stabilizer bar must be aligned with the raised
line in the center of the front suspension cradle (Fig.
37).
(4) Install the stabilizer bar link mounting stud
through the hole in each end of the stabilizer bar
(Fig. 33).
CAUTION: When installing the nut on the mounting
stud of the stabilizer bar link, do not allow the stud
to rotate in it's socket. Hold the stud from rotating
by placing an open-end wrench on the flat
machined into the stud (Fig. 33).
(5) Hand-thread the nut on the end of each stabi-
lizer bar link stud. Hold the studs from turning by
placing an open-end wrench on the flat machined
into the link's mounting stud, then tighten each nut
while holding the wrench in place (Fig. 33). Tighten
each nut to a torque of 88 N´m (65 ft. lbs.).
(6) Tighten the stabilizer bar bushing retainer to
cradle attaching bolts (Fig. 34) to 68 N´m (50 ft. lbs.)
torque.
(7) Install the reinforcement on the front suspen-
sion cradle crossmember and install the bolts attach-
ing the reinforcement to the cradle crossmember
(Fig. 32). Tighten the M-14 size bolts to a torque of
153 N´m (113 ft. lbs.). Tighten the M-12 size bolts to
a torque of 106 N´m (78 ft. lbs.).
(8) Install the lower control arm rear bushing
retainer bolts through reinforcement on each side of
each lower control arm rear bushing. Tighten these
M-10 size bolts to a torque of 61 N´m (45 ft. lbs.).(9) Install the two bolts and bushings attaching
the reinforcement and rear of cradle crossmember to
body of vehicle (Fig. 32). Tighten bolts to a torque of
163 N´m (120 ft. lbs.).
(10) Install the power steering cooler (Fig. 31).
Tighten bolts to a torque of 11 N´m (100 in. lbs.).
(11) Lower the vehicle.
STRUT
DESCRIPTION - STRUT ASSEMBLY
A Macpherson type strut assembly is used in place
of a conventional front suspension's upper control
arm and upper ball joint. The bottom of the strut
mounts directly to the steering knuckle using two
bolts and nuts going through the strut clevis bracket
and steering knuckle. The top of the strut mounts
directly to the strut tower of the vehicle using the
threaded studs on the strut assemblies upper mount.
The strut assembly includes the components listed
in the figure (Fig. 38).
Each component is serviced by removing the strut
assembly from the vehicle and disassembling it.
The coil springs are side-oriented. Springs on the
left side of the vehicle have a left-hand wind top-to-
bottom while springs on the right side have a right-
hand wind top-to-bottom. This helps provide better
vehicle stability during jounce and rebound maneu-
vers of the front suspension. Left and right springs
must not be interchanged. Coil springs are rated sep-
arately for each corner or side of the vehicle depend-
ing on optional equipment and type of vehicle
service. If the coil springs require replacement, be
sure that the springs are replaced with springs meet-
ing the correct load rating and spring rate for the
vehicle and its specific options.
OPERATION - STRUT ASSEMBLY
The strut assembly cushions the ride of the vehicle,
controlling vibration, along with jounce and rebound
of the suspension.
The coil spring controls ride quality and maintains
proper ride height.
The spring isolators isolate the coil spring at the
top and bottom from coming into metal-to-metal con-
tact with the upper seat and strut.
The jounce bumper limits suspension travel and
metal-to-metal contact under full jounce condition.
The strut dampens jounce and rebound motions of
the coil spring and suspension.
During steering maneuvers, the strut assembly
(through a pivot bearing in the upper strut mount)
and steering knuckle (through the lower ball joint)
turn as an assembly.
Fig. 37 Stabilizer Bar Correctly Positioned In Cradle
1 - RAISED BEAD
2-SWAYBAR
3 - WHEN INSTALLING SWAY BAR THE RAISED BEAD ON THE
SUSPENSION CRADLE MUST BE IN THE CENTER OF RADIUS
IN SWAY BAR
4 - FRONT SUSPENSION CRADLE
RSFRONT SUSPENSION2-19
STABILIZER BAR (Continued)
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(10) Remove the dust shield and jounce bumper as
an assembly from the strut shaft by pulling both
straight up and off the strut shaft. The dust shield
cannot be separated from the jounce bumper until
after it is removed from strut shaft.
(11) Remove the jounce bumper from the dust
shield. The jounce bumper is removed from the dust
shield by collapsing the dust shield until the jounce
bumper can be pulled free from the dust boot.
(12) Remove the spring isolator from the lower
spring seat on the strut (Fig. 38).
(13) Inspect the strut assembly components (Fig.
38) for the following and replace as necessary:
²Inspect the strut for any condition of shaft bind-
ing over the full stroke of the shaft.
²Check the upper mount for cracks and distortion
and its retaining studs for any sign of damage.
²Check the upper seat for stress cracks and wear.
²Check the upper spring isolator for severe dete-
rioration.
²Check for binding of the strut assembly pivot
bearing.
²Inspect the dust shield for rips and deteriora-
tion.
²Inspect the jounce bumper for cracks and signs
of deterioration.
ASSEMBLY - STRUT ASSEMBLY
For the disassembly and assembly of the strut
assembly, use of Strut Spring Compressor, Pentastar
Service Equipment (PSE) tool W-7200, or the equiva-
lent, is recommended to compress the coil spring.
Follow the manufacturer's instructions closely.
NOTE: Coil Springs on this vehicle are side-ori-
ented. Springs on the left side of the vehicle have a
left-hand wind top-to-bottom while springs on the
right side have a right-hand wind top-to-bottom.
Left and right springs must not be interchanged.
NOTE: If the coil spring has been removed from the
spring compressor, proceed with the next step, oth-
erwise, proceed with step 5.
(1) Place the coil spring in the compressor lower
hooks following the manufacturers instructions.
Proper orientation of the spring to the strut (once
installed) is necessary. Consider the following when
placing the coil spring in the compressor: From
above, the compressor back is at the 12 o'clock posi-
tion, and you, standing in the front of the machine,
are at the 6 o'clock position. Place the lower coil
spring end at the 6 o'clock position for both left and
right springs. (Fig. 46).
(2) Install the upper seat and upper isolator on top
of the coil spring. Position the notch in the perimeterof the upper seat toward the front of the compressor
(same 6 o'clock position as in step 1).
(3) Position the upper hooks on top of the coil
spring upper seat so the upper hooks span approxi-
mately 1 inch past outside diameter of upper seat
(Fig. 47). This will allow proper clearance for upper
mount installation without pinching the hooks in-be-
tween the two pieces.Do not allow hooks to be
placed closer to edge.
(4) Compress the coil spring far enough to allow
strut installation.
(5) If the pivot bearing has been removed from the
upper seat, install the pivot bearing on the top of the
upper spring seat (Fig. 48). The bearing must be
installed on upper seat with the smaller diameter
Fig. 46 Spring Positioned In Compressor (Right
Spring Shown)
1 - COMPRESSOR LOWER HOOKS
2 - COIL SPRING END
Fig. 47 Hook Placement On Upper Seat
1 - HOOKS POSITIONED 1 INCH FROM EDGE
2 - PIVOT BEARING AND UPPER SEAT
RSFRONT SUSPENSION2-23
STRUT (Continued)
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sion is relieved, make sure the upper mount, pivot
bearing and upper seat are align properly. Remove
the clamp from the lower end of the coil spring and
strut. Push back the spring compressor upper and
lower hooks, then remove the strut assembly from
the spring compressor.
(13) Install strut assembly on the vehicle. (Refer to
2 - SUSPENSION/FRONT/STRUT - INSTALLA-
TION)
INSTALLATION - STRUT ASSEMBLY
CAUTION: Front strut coil springs are side-oriented.
When installing a strut assembly, make sure the
strut being installed has the correct coil spring for
that side of the vehicle. Springs on the left side of
the vehicle have a left-hand wind top-to-bottom
while springs on the right side have a right-hand
wind top-to-bottom (Fig. 49). Do not interchange the
two sides.
(1) Install strut assembly into strut tower, aligning
and installing the 3 studs on the upper strut mount
into the holes in shock tower. Install the 3 upper
strut mount attaching nut/washer assemblies (Fig.
43). Then using a crow foot. tighten the 3 attaching
nuts to a torque of 28 N´m (250 in. lbs.).
CAUTION: The steering knuckle to strut assembly
attaching bolts are serrated and must not be turned
during installation. Install nuts while holding bolts
stationary in the steering knuckles.
NOTE: The strut clevis-to-steering knuckle bolts are
installed differently on each side of the vehicle. Left
hand side bolts are to be installed from vehicle rear
to front. Right side bolts are to be installed from
vehicle front to rear.(2) Align strut assembly with steering knuckle.
Position arm of steering knuckle into strut assembly
clevis bracket. Align the strut assembly clevis
bracket mounting holes with the steering knuckle
mounting holes. Install the 2 strut assembly to steer-
ing knuckle attaching bolts (Fig. 42).If strut assem-
bly is attached to steering knuckle using a cam
bolt, the cam bolt must be installed in the lower
slotted hole on strut clevis bracket.Tighten the
strut clevis-to-steering knuckle attaching bolts to a
torque of 81 N´m (60 ft. lbs.) plus an additional 1/4
(90É) turn after specified torque is met.
(3) Install the stabilizer bar link mounting stud
through the bracket on the strut assembly (Fig. 41).
CAUTION: When installing the nut on the mounting
stud of the stabilizer bar link, do not allow the stud
to rotate in it's socket. Hold the stud from rotating
by placing an open-end wrench on the flat
machined into the stud (Fig. 41).
(4) Hand thread the nut on the end of the stabi-
lizer bar link stud. Hold the stud from turning by
placing an open-end wrench on the flat machined
into the link's mounting stud, then tighten the nut
while holding the wrench in place (Fig. 41). Tighten
the nut to a torque of 88 N´m (65 ft. lbs.).
(5) Install the hydraulic brake hose and speed sen-
sor cable routing brackets on the strut assembly
brackets (Fig. 40). Tighten the routing bracket
attaching bolts to a torque of 13 N´m (10 ft. lbs.).
(6) Install the wheel/tire assembly on the vehicle.
(7) Install and tighten the wheel mounting stud
nuts in proper sequence until all nuts are torqued to
half specification. Then repeat the tightening
sequence to the full specified torque of 135 N´m (100
ft. lbs.).
RSFRONT SUSPENSION2-25
STRUT (Continued)
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plug from the adjustment hole in each brake support
plate to provide visual access of the brake adjuster
star wheel.
To eliminate the condition where maximum adjust-
ment of the rear brake shoes does not allow the auto-
matic adjuster to operate when tested, back the star
wheel off approximately 30 notches. It will be neces-
sary to hold the adjuster lever away from the star
wheel to permit this adjustment.
Have the helper apply the brakes. Upon applica-
tion of the brake pedal, the adjuster lever should
move down, turning the adjuster star wheel. Thus, a
definite rotation of the adjuster star wheel can be
observed if the automatic adjuster is working prop-
erly. If one or more adjusters do not function prop-
erly, the respective drum must be removed for
adjuster servicing.
BRAKE LINES
DESCRIPTION - BRAKE TUBES AND HOSES
The brake tubes are steel with a corrosion-resis-
tant nylon coating applied to the external surfaces.
The flex hoses are made of reinforced rubber with fit-
tings at each end.
The primary and secondary brake tubes leading
from the master cylinder to the ABS ICU Hydraulic
Control Unit (HCU) or the non-ABS junction block
have a special flexible section. This flexible section is
required due to cradle movement while the vehicle is
in motion (The ICU and non-ABS junction block are
mounted to the cradle).If replacement of these
lines is necessary, only the original factory
brake line containing the flexible section must
be used.
OPERATION - BRAKE TUBES AND HOSES
The purpose of the chassis brake tubes and flex
hoses is to transfer the pressurized brake fluid devel-
oped by the master cylinder to the wheel brakes of
the vehicle. The flex hoses are made of rubber to
allow for the movement of the vehicle's suspension.
INSPECTION - BRAKE TUBES AND HOSES
Flexible rubber hose is used at both front brakes
and at the rear axle. Inspection of brake hoses
should be performed whenever the brake system is
serviced and every 7,500 miles or 12 months, which-
ever comes first (every engine oil change). Inspect
hydraulic brake hoses for surface cracking, scuffing,
or worn spots. If the fabric casing of the rubber hose
becomes exposed due to cracks or abrasions in the
rubber hose cover, the hose should be replaced imme-
diately. Eventual deterioration of the hose can take
place with possible burst failure. Faulty installation
can cause twisting, resulting in wheel, tire, or chassis
interference.
The brake tubing should be inspected periodically
for evidence of physical damage or contact with mov-
ing or hot components.
The flexible brake tube sections used on this vehi-
cle in the primary and secondary tubes from the
master cylinder to the ABS hydraulic control unit
connections must also be inspected. This flexible tub-
ing must be inspected for kinks, fraying and contact
with other components or with the body of the vehi-
cle.
BRAKE PADS/SHOES - FRONT
REMOVAL
REMOVAL - FRONT DISC BRAKE SHOES
(DISC/DISC BRAKES)
(1) Raise the vehicle. (Refer to LUBRICATION &
MAINTENANCE/HOISTING - STANDARD PROCE-
DURE).
(2) Remove both front wheel and tire assemblies.
(3) Begin on one side of the vehicle.
(4) Remove the anti-rattle clip from the outboard
side of the caliper and adapter.
(5) Remove the two caliper guide pin bolts.
(6) Remove caliper from caliper adapter and brake
rotor.
CAUTION: Supporting weight of caliper by the flex-
ible brake fluid hose can damage the hose.
(7) Using wire or cord, hang the caliper from the
front strut assembly (Fig. 12). Support the caliper
Fig. 11 Caliper Piston Seal Function For Automatic
Adjustment
1 - PISTON
2 - CYLINDER BORE
3 - PISTON SEAL BRAKE PRESSURE OFF
4 - CALIPER HOUSING
5 - DUST BOOT
6 - PISTON SEAL BRAKE PRESSURE ON
5 - 14 BRAKES - BASERS
HYDRAULIC/MECHANICAL (Continued)
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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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SHIFT SCHEDULES
As mentioned earlier, the PCM has programming
that allows it to select a variety of shift schedules.
Shift schedule selection is dependent on the follow-
ing:
²Shift lever position
²Throttle position²Engine load
²Fluid temperature
²Software level
As driving conditions change, the PCM appropri-
ately adjusts the shift schedule. Refer to the follow-
ing chart to determine the appropriate operation
expected, depending on driving conditions.
Schedule Condition Expected Operation
Extreme ColdOil temperature at start-up below
-16É FPark, Reverse, Neutral and 2nd
gear only (prevents shifting which
may fail a clutch with frequent
shifts)
ColdOil temperature at start-up above
-12É F and below 36É F± Delayed 2-3 upshift
(approximately 22-31 mph)
± Delayed 3-4 upshift (45-53 mph)
± Early 4-3 costdown shift
(approximately 30 mph)
± Early 3-2 coastdown shift
(approximately 17 mph)
± High speed 4-2, 3-2, 2-1 kickdown
shifts are prevented
± No EMCC
WarmOil temperature at start-up above
36É F and below 80 degree F± Normal operation (upshift,
kickdowns, and coastdowns)
± No EMCC
HotOil temperature at start-up above
80É F± Normal operation (upshift,
kickdowns, and coastdowns)
± Full EMCC, no PEMCC except to
engage FEMCC (except at closed
throttle at speeds above 70-83 mph)
OverheatOil temperature above 240É F or
engine coolant temperature above
244É F± Delayed 2-3 upshift (25-32 mph)
± Delayed 3-4 upshift (41-48 mph)
± 3rd gear FEMCC from 30-48 mph
± 3rd gear PEMCC from 27-31 mph
Super OverheatOil temperature above 260É F ± All9Overheat9shift schedule
features apply
± 2nd gear PEMCC above 22 mph
± Above 22 mph the torque
converter will not unlock unless the
throttle is closed or if a wide open
throttle 2nd PEMCC to 1 kickdown
is made
8E - 14 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
ProCarManuals.com

In addition to monitoring inputs and controlling
outputs, the TCM has other important responsibili-
ties and functions:
²Storing and maintaining Clutch Volume Indices
(CVI)
²Storing and selecting appropriate Shift Sched-
ules
²System self-diagnostics
²Diagnostic capabilities (with DRB scan tool)
CLUTCH VOLUME INDEX (CVI)
An important function of the TCM is to monitor
Clutch Volume Index (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.
The TCM 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 TCM that represents input shaft rpm. The Out-
put Speed Sensor provides the TCM with output
shaft speed information.
By comparing the two inputs, the TCM can deter-
mine transaxle gear ratio. This is important to the
CVI calculation because the TCM determines CVIs
by monitoring how long it takes for a gear change to
occur (Fig. 17).
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 TCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changes
to 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 TCM 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 foradaptive 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. 17 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-21
TRANSMISSION CONTROL MODULE (Continued)
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SHIFT SCHEDULES
As mentioned earlier, the TCM has programming
that allows it to select a variety of shift schedules.
Shift schedule selection is dependent on the follow-
ing:
²Shift lever position
²Throttle position²Engine load
²Fluid temperature
²Software level
As driving conditions change, the TCM appropri-
ately adjusts the shift schedule. Refer to the follow-
ing chart to determine the appropriate operation
expected, depending on driving conditions.
Schedule Condition Expected Operation
Extreme ColdOil temperature at start-up below
-16É FPark, Reverse, Neutral and 2nd
gear only (prevents shifting which
may fail a clutch with frequent
shifts)
ColdOil temperature at start-up above
-12É F and below 36É F± Delayed 2-3 upshift
(approximately 22-31 mph)
± Delayed 3-4 upshift (45-53 mph)
± Early 4-3 costdown shift
(approximately 30 mph)
± Early 3-2 coastdown shift
(approximately 17 mph)
± High speed 4-2, 3-2, 2-1 kickdown
shifts are prevented
± No EMCC
WarmOil temperature at start-up above
36É F and below 80 degree F± Normal operation (upshift,
kickdowns, and coastdowns)
± No EMCC
HotOil temperature at start-up above
80É F± Normal operation (upshift,
kickdowns, and coastdowns)
± Full EMCC, no PEMCC except to
engage FEMCC (except at closed
throttle at speeds above 70-83 mph)
OverheatOil temperature above 240É F or
engine coolant temperature above
244É F± Delayed 2-3 upshift (25-32 mph)
± Delayed 3-4 upshift (41-48 mph)
± 3rd gear FEMCC from 30-48 mph
± 3rd gear PEMCC from 27-31 mph
Super OverheatOil temperature above 260É F ± All9Overheat9shift schedule
features apply
± 2nd gear PEMCC above 22 mph
± Above 22 mph the torque
converter will not unlock unless the
throttle is closed or if a wide open
throttle 2nd PEMCC to 1 kickdown
is made
8E - 22 ELECTRONIC CONTROL MODULESRS
TRANSMISSION CONTROL MODULE (Continued)
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