ESP CHRYSLER VOYAGER 2004 Repair Manual

FUEL INJECTION
OPERATION
OPERATION - INJECTION SYSTEM
All engines used in this section have a sequential
Multi-Port Electronic Fuel Injection system. The MPI
system is computer regulated and provides precise
air/fuel ratios for all driving conditions. The Power-
train Control Module (PCM) operates the fuel injec-
tion system.
The PCM regulates:
²Ignition timing
²Air/fuel ratio
²Emission control devices
²Cooling fan
²Charging system
²Idle speed
²Vehicle speed control
Various sensors provide the inputs necessary for
the PCM to correctly operate these systems. In addi-
tion to the sensors, various switches also provide
inputs to the PCM.
The PCM can adapt its programming to meet
changing operating conditions.
Fuel is injected into the intake port above the
intake valve in precise metered amounts through
electrically operated injectors. The PCM fires the
injectors in a specific sequence. Under most operat-
ing conditions, the PCM maintains an air fuel ratio
of 14.7 parts air to 1 part fuel by constantly adjust-
ing injector pulse width. Injector pulse width is the
length of time the injector is open.
The PCM adjusts injector pulse width by opening
and closing the ground path to the injector. Engine
RPM (speed) and manifold absolute pressure (air
density) are theprimaryinputs that determine
injector pulse width.
OPERATION - MODES OF OPERATION
As input signals to the PCM change, the PCM
adjusts its response to output devices. For example,
the PCM must calculate a different injector pulse
width and ignition timing for idle than it does for
Wide Open Throttle (WOT). There are several differ-
ent modes of operation that determine how the PCM
responds to the various input signals.
There are two different areas of operation, OPEN
LOOP and CLOSED LOOP.
During OPEN LOOP modes the PCM receives
input signals and responds according to preset PCM
programming. Inputs from the upstream and down-
stream heated oxygen sensors are not monitored dur-
ing OPEN LOOP modes, except for heated oxygensensor diagnostics (they are checked for shorted con-
ditions at all times).
During CLOSED LOOP modes the PCM monitors
the inputs from the upstream and downstream
heated oxygen sensors. The upstream heated oxygen
sensor input tells the PCM if the calculated injector
pulse width resulted in the ideal air-fuel ratio of 14.7
to one. By monitoring the exhaust oxygen content
through the upstream heated oxygen sensor, the
PCM can fine tune injector pulse width. Fine tuning
injector pulse width allows the PCM to achieve opti-
mum fuel economy combined with low emissions.
For the PCM to enter CLOSED LOOP operation,
the following must occur:
(1) Engine coolant temperature must be over 35ÉF.
²If the coolant is over 35ÉF the PCM will wait 38
seconds.
²If the coolant is over 50ÉF the PCM will wait 15
seconds.
²If the coolant is over 167ÉF the PCM will wait 3
seconds.
(2) For other temperatures the PCM will interpo-
late the correct waiting time.
(3) O2 sensor must read either greater than 0.745
volts or less than 0.29 volt.
(4) The multi-port fuel injection systems has the
following modes of operation:
²Ignition switch ON (Zero RPM)
²Engine start-up
²Engine warm-up
²Cruise
²Idle
²Acceleration
²Deceleration
²Wide Open Throttle
²Ignition switch OFF
(5) The engine start-up (crank), engine warm-up,
deceleration with fuel shutoff and wide open throttle
modes are OPEN LOOP modes. Under most operat-
ing conditions, the acceleration, deceleration (with
A/C on), idle and cruise modes,with the engine at
operating temperatureare CLOSED LOOP modes.
IGNITION SWITCH ON (ZERO RPM) MODE
When the ignition switch activates the fuel injec-
tion system, the following actions occur:
²The PCM monitors the engine coolant tempera-
ture sensor and throttle position sensor input. The
PCM determines basic fuel injector pulse width from
this input.
²The PCM determines atmospheric air pressure
from the MAP sensor input to modify injector pulse
width.
When the key is in the ON position and the engine
is not running (zero rpm), the Auto Shutdown (ASD)
and fuel pump relays de-energize after approximately
14 - 18 FUEL INJECTIONRS

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)

weather, high pressure area. This is important
because as air pressure changes the barometric pres-
sure changes. Barometric pressure and altitude have
a direct inverse correlation, as altitude goes up baro-
metric goes down. The first thing that happens as
the key is rolled on, before reaching the crank posi-
tion, the PCM powers up, comes around and looks at
the MAP voltage, and based upon the voltage it sees,
it knows the current barometric pressure relative to
altitude. Once the engine starts, the PCM looks at
the voltage again, continuously every 12 milliseconds,
and compares the current voltage to what it was at
key on. The difference between current and what it
was at key on is manifold vacuum.
During key On (engine not running) the sensor
reads (updates) barometric pressure. A normal range
can be obtained by monitoring known good sensor in
you work area.
As the altitude increases the air becomes thinner
(less oxygen). If a vehicle is started and driven to a
very different altitude than where it was at key On
the barometric pressure needs to be updated. Any
time the PCM sees Wide Open throttle, based upon
TPS angle and RPM it will update barometric pres-
sure in the MAP memory cell. With periodic updates,
the PCM can make its calculations more effectively.
The PCM uses the MAP sensor to aid in calculat-
ing the following:
²Barometric pressure
²Engine load
²Manifold pressure
²Injector pulse-width
²Spark-advance programs
²Shift-point strategies (F4AC1 transmissions
only, via the PCI bus)
²Idle speed²Decel fuel shutoff
The PCM recognizes a decrease in manifold pres-
sure by monitoring a decrease in voltage from the
reading stored in the barometric pressure memory
cell. The MAP sensor is a linear sensor; as pressure
changes, voltage changes proportionately. The range
of voltage output from the sensor is usually between
4.6 volts at sea level to as low as 0.3 volts at 26 in. of
Hg. Barometric pressure is the pressure exerted by
the atmosphere upon an object. At sea level on a
standard day, no storm, barometric pressure is 29.92
in Hg. For every 100 feet of altitude barometric pres-
sure drops .10 in. Hg. If a storm goes through it can
either add, high pressure, or decrease, low pressure,
from what should be present for that altitude. You
should make a habit of knowing what the average
pressure and corresponding barometric pressure is
for your area.REMOVAL
REMOVAL - 2.4L
(1) Disconnect the negative battery cable.
(2) Disconnect electrical connector and vacuum
hose from MAP sensor (Fig. 20).
(3) Remove two screws holding sensor to the
intake manifold.
REMOVAL - 3.3/3.8L
(1) Disconnect the negative battery cable.
(2) Remove vacuum hose and mounting screws
from manifold absolute pressure (MAP) sensor (Fig.
21).
(3) Disconnect electrical connector from sensor.
Remove sensor.
INSTALLATION
INSTALLATION - 2.4L
(1) Install sensor.
(2) Install two screws and tighten.
(3) Connect the electrical connector and vacuum
hose to the MAP sensor (Fig. 20).
(4) Connect the negative battery cable.
INSTALLATION - 3.3/3.8L
(1) Install sensor (Fig. 21).
(2) Install screws and tighten toPLASTIC MAN-
IFOLD 1.7 N´m (15 in. lbs.) ALUMINUM MANI-
FOLD 3.3 N´m (30 in. lbs.).
(3) Connect the electrical connector to the sensor.
Install vacuum hose.
(4) Connect the negative battery cable.
Fig. 21 MAP SENSOR - 3.3/3.8L
RSFUEL INJECTION14-31
MAP SENSOR (Continued)

STEERING
TABLE OF CONTENTS
page page
STEERING
DESCRIPTION - POWER STEERING SYSTEM . . 1
OPERATION - POWER STEERING SYSTEM . . . 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER
STEERING SYSTEM FLOW AND
PRESSURE TEST......................1
DIAGNOSIS AND TESTING - STEERING
SYSTEM DIAGNOSIS CHARTS............3SPECIFICATIONS
POWER STEERING FASTENER TORQUE . . . 9
SPECIAL TOOLS
POWER STEERING....................9
COLUMN..............................10
GEAR.................................26
PUMP.................................36
STEERING
DESCRIPTION - POWER STEERING SYSTEM
This vehicle comes with power steering as stan-
dard equipment. The power steering system consists
of these major components:
²POWER STEERING PUMP
²POWER STEERING GEAR
²POWER STEERING FLUID
²POWER STEERING FLUID COOLER
²POWER STEERING FLUID RESERVOIR
²POWER STEERING FLUID SUPPLY HOSE
²POWER STEERING FLUID PRESSURE HOSE
²POWER STEERING FLUID RETURN HOSE
For information on the first two components, refer
to their respective sections within this service man-
ual group. Information on all other components can
be found in POWER STEERING PUMP.
OPERATION - POWER STEERING SYSTEM
Turning of the steering wheel is converted into lin-
ear (side-to-side) travel through the meshing of the
helical pinion teeth with the rack teeth within the
steering gear. The lateral travel pushes and pulls the
tie rods to change the direction of the vehicle's front
wheels.
Power assist steering is provided by a belt driven
rotary type pump. It directs fluid through power
steering fluid hoses to the power steering gear where
it is used to assist the driver's turning effort.
Manual steering control of the vehicle can be main-
tained if power steering assist is lost. However,
under this condition, steering effort is significantly
increased.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - POWER STEERING
SYSTEM FLOW AND PRESSURE TEST
ALL ENGINES
The following procedure is to be used to test the
operation of the power steering system on this vehi-
cle. This test will provide the flow rate of the power
steering pump along with the maximum relief pres-
sure. This test is to be performed to determine if the
power steering pump or power steering gear is not
functioning properly. The following flow and pressure
test is performed using the Power Steering Analyzer
Kit, Special Tool 6815 (Fig. 1), hoses, Special Tools
6905 and 6959, and fittings from adapter kit, Special
Tool 6893.
Fig. 1 Power Steering Analyzer With Hoses Installed
1 - OUTLET
2 - SPECIAL TOOL 6815
3 - INLET
RSSTEERING19-1

(3) Clutch circuit leaks are indicated if pressures
do not fall within the specified pressure range.
(4)
If the overdrive clutch pressure is greater than 5
psi in Step 4 of Test Three, a worn reaction shaft seal
ring or a defective solenoid assembly is indicated.
(5) If the underdrive clutch pressure is greater
than 5 psi in Step 4 of Test Two A, a defective sole-
noid assembly or PCM/TCM is the cause.
PRESSURE CHECK SPECIFICATIONS
Gear Selector
PositionActual GearPressure Taps
Underdrive
ClutchOverdrive
ClutchReverse
ClutchTorque
Converter
Clutch
Off2/4
ClutchLow/
Reverse
Clutch
Park *
PARK 0-2 0-5 0-2 60-110 0-2 115-145
0 mph
REVERSE *
REVERSE 0-2 0-7 165-235 50-100 0-2 165-235
0 mph
NEUTRAL *
NEUTRAL 0-2 0-5 0-2 60-110 0-2 115-145
0 mph
L#
FIRST 110-145 0-5 0-2 60-110 0-2 115-145
20 mph
3#
SECOND 110-145 0-5 0-2 60-110 115-145 0-2
30 mph
3#
DIRECT 75-95 75-95 0-2 60-90 0-2 0-2
45 mph
OD #
OVERDRIVE 0-2 75-95 0-2 60-90 75-95 0-2
30 mph
OD #
OVERDRIVE
WITH TCC0-2 75-95 0-2 0-5 75-95 0-2
50 mph
* Engine speed at 1500 rpm
# CAUTION: Both front wheels must be turning at the same speed.
DIAGNOSIS AND TESTING - CLUTCH AIR
PRESSURE TESTS
Inoperative clutches can be located using a series
of tests by substituting air pressure for fluid pressure
(Fig. 5) (Fig. 6). The clutches may be tested by apply-
ing air pressure to their respective passages. The
valve body must be removed and Tool 6056 installed.
To make air pressure tests, proceed as follows:
NOTE: The compressed air supply must be free of
all dirt and moisture. Use a pressure of 30 psi.
Remove oil pan and valve body. See Valve body
removal.
OVERDRIVE CLUTCH
Apply air pressure to the overdrive clutch apply
passage and watch for the push/pull piston to moveforward. The piston should return to its starting
position when the air pressure is removed.
REVERSE CLUTCH
Apply air pressure to the reverse clutch apply pas-
sage and watch for the push/pull piston to move rear-
ward. The piston should return to its starting
position when the air pressure is removed.
2/4 CLUTCH
Apply air pressure to the feed hole located on the
2/4 clutch retainer. Look in the area where the 2/4
piston contacts the first separator plate and watch
carefully for the 2/4 piston to move rearward. The
piston should return to its original position after the
air pressure is removed.
21 - 122 41TE AUTOMATIC TRANSAXLERS
41TE AUTOMATIC TRANSAXLE (Continued)

OPERATION
The function of an accumulator is to cushion the
application of a frictional clutch element. When pres-
surized fluid is applied to a clutch circuit, the appli-
cation force is dampened by fluid collecting in the
respective accumulator chamber against the piston
and spring(s). The intended result is a smooth, firm
clutch application.
AUTOSTICK SWITCH
DESCRIPTION
Autostick is a driver-interactive transaxle feature
that offers manual gear shifting capability. The control
switch is part of the transaxle gear shift lever as
shown in (Fig. 171). It can only be serviced by replac-
ing the gearshift lever assembly. (Refer to 19 - STEER-
ING/COLUMN/GEAR SHIFT LEVER - REMOVAL)
OPERATION
When the shift lever is moved into the Autostick
position (as indicated by the Shift Lever Position
Indicator in the cluster), the transaxle remains in
whatever gear it was using before Autostick was acti-
vated. The TCM sends a 5 volt signal through the
switch and then monitors the signal for voltage drop.
Each switch state (driver command) results in a spe-
cific voltage reading sensed by the TCM. The TCM
then determines transaxle operation (upshift/down-
shift/OD Lockout) based on their corresponding volt-
age. Refer to the following chart for corresponding
switch states and voltage readings:
Switch State Voltage Reading
Autostick DOWN
depressed0.3V-1.6V
Autostick UP depressed 1.6V-2.8V
Overdrive OFF9Lockout9
depressed2.8V-3.8V
All switches open 3.8V-4.8V
-Voltage values <.3V and >4.8V are considered
INVALID and will result in a DTC
Fig. 169 Low/Reverse Accumulator Assembly
1 - ACCUMULATOR PISTON
2 - SEAL RINGS
3 - RETURN SPRINGS
4 - (NOTE NOTCH)
Fig. 170 2/4 Accumulator Assembly
1 - VALVE BODY
2 - RETAINER PLATE
3 - DETENT SPRING
4 - SPRINGS
5 - SEALS
6 - PISTON
Fig. 171 Autostick Switch Location (if equipped)
RS41TE AUTOMATIC TRANSAXLE21 - 189
ACCUMULATOR (Continued)

Moving the switch up causes an upshift and moving
the switch down causes a downshift. The instrument
cluster will illuminate the selected gear. The vehicle
can be launched in 1st, 2nd, or 3rd gear while in the
Autostick mode. The speed control is operable in 3rd
and 4th gear Autostick mode. Speed control will be
deactivated if the transaxle is shifted to 2nd gear.
Shifting into OD position cancels the Autostick mode,
and the transaxle resumes the OD shift schedule.
DRIVING CLUTCHES
DESCRIPTION
Three hydraulically applied input clutches are used
to drive planetary components. The underdrive, over-
drive, and reverse clutches are considered input
clutches and are contained within the input clutch
assembly (Fig. 172). The input clutch assembly also
contains:
²Input shaft
²Input hub
²Clutch retainer
²Underdrive piston
²Overdrive/reverse piston
²Overdrive hub
²Underdrive hub
OPERATION
The three input clutches are responsible for driving
different components of the planetary geartrain.
NOTE: Refer to the ªElements In Useº chart in Diag-
nosis and Testing for a collective view of which
clutch elements are applied at each position of the
selector lever.
UNDERDRIVE CLUTCH
The underdrive clutch is hydraulically applied in
first, second, and third (direct) gears by pressurized
fluid against the underdrive piston. When the under-
drive clutch is applied, the underdrive hub drives the
rear sun gear.
OVERDRIVE CLUTCH
The overdrive clutch is hydraulically applied in
third (direct) and overdrive gears by pressurized fluid
against the overdrive/reverse piston. When the over-
drive clutch is applied, the overdrive hub drives the
front planet carrier.
REVERSE CLUTCH
The reverse clutch is hydraulically applied in
reverse gear only by pressurized fluid against the
overdrive/reverse piston. When the reverse clutch is
applied, the front sun gear assembly is driven.
FINAL DRIVE
DISASSEMBLY
NOTE: The differential is serviced as an assembly.
Differential service is limited to bearing cups and
cones. Any other differential component failure
must be remedied by differential assembly and
transfer shaft replacement.
Fig. 172 Input Clutch Assembly
1 - INPUT SHAFT
2 - UNDERDRIVE CLUTCH
3 - OVERDRIVE CLUTCH
4 - REVERSE CLUTCH
5 - OVERDRIVE SHAFT
6 - UNDERDRIVE SHAFT
21 - 190 41TE AUTOMATIC TRANSAXLERS
AUTOSTICK SWITCH (Continued)

A conventional mechanical interlock system is also
used. This system manually prohibits shifter move-
ment when the ignition switch is in the LOCK or
ACC positions. Solenoid operation is not required in
these key positions.
For intended BTSI system operation, refer to the
following chart:
ACTION EXPECTED RESPONSE
1. Turn key to the9OFF9
position.1. Shifter CAN be shifted
out of park with brake
pedal applied.
2. Turn key to the
9ON/RUN9position.2. Shifter CANNOT be
shifted out of park.
3. Turn key to the
9ON/RUN9position and
depress the brake pedal.3. Shifter CAN be shifted
out of park.
4. Leave shifter in any
gear and try to return key
to the9LOCK9or9ACC9
position.4. Key cannot be
returned to the9LOCK9or
9ACC9position.
5. Return shifter to
9PARK9and try to remove
the key.5. Key can be removed
(after returning to9LOCK9
position).
6. With the key removed,
try to shift out of9PARK9.6. Shifter cannot be
shifted out of9PARK9.
NOTE: Any failure to meet these expected
responses requires system adjustment or repair.
Fig. 293 Ignition Key/Switch Positions
1 - ACC
2 - LOCK
3 - OFF
4 - ON/RUN
5-START
Fig. 294 Pawl Engaged to Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
Fig. 295 Pawl Disengaged From Shift Lever
1 - GEAR SHIFT LEVER
2 - GEAR SHIFT LEVER PAWL
21 - 234 41TE AUTOMATIC TRANSAXLERS
SHIFT INTERLOCK SOLENOID (Continued)

DIAGNOSIS AND TESTING - BRAKE/
TRANSMISSION SHIFT INTERLOCK SOLENOID
For intended BTSI system operation, refer to the
following chart:
ACTION EXPECTED RESPONSE
1. Turn key to the9OFF9
position.1. Shifter CAN be shifted
out of park with brake
pedal applied.
2. Turn key to the
9ON/RUN9position.2. Shifter CANNOT be
shifted out of park.
3. Turn key to the
9ON/RUN9position and
depress the brake pedal.3. Shifter CAN be shifted
out of park.
4. Leave shifter in any
gear and try to return key
to the9LOCK9or9ACC9
position.4. Key cannot be
returned to the9LOCK9or
9ACC9position.
5. Return shifter to
9PARK9and try to remove
the key.5. Key can be removed
(after returning to9LOCK9
position).
6. With the key removed,
try to shift out of9PARK9.6. Shifter cannot be
shifted out of9PARK9.
NOTE: Any failure to meet these expected
responses requires system repair. Refer to the
appropriate Diagnostic Information.
REMOVAL
(1) Disconnect battery negative cable.
(2) Remove instrument panel lower shroud (Fig.
296).(3) Remove knee bolster (Fig. 297).
(4) Remove steering column lower shroud.
(5) Disconnect brake/transmission shift interlock
(BTSI) solenoid connector (Fig. 298).
(6) Remove two (2) solenoid-to-column screws (Fig.
299).
(7) Remove solenoid.
Fig. 296 Instrument Panel Lower Silencer
1 - INSTRUMENT PANEL LOWER SILENCER
Fig. 297 Knee Bolster
1 - KNEE BOLSTER
Fig. 298 BTSI Solenoid Connector
1 - BTSI SOLENOID
2 - SOLENOID CONNECTOR
RS41TE AUTOMATIC TRANSAXLE21 - 235
SHIFT INTERLOCK SOLENOID (Continued)

Since there are four switches, there are 16 possible
combinations of open and closed switches (codes).
Seven of these codes are related to gear position and
three are recognized as ªbetween gearº codes. This
results in six codes which should never occur. These
are called ªinvalidº codes. An invalid code will result
in a DTC, and the PCM/TCM will then determine the
shift lever position based on pressure switch data.
This allows reasonably normal transmission opera-
tion with a TRS failure.
TRS SWITCH STATES
SLP T42 T41 T3 T1
PCL CL CL OP
RCL OP OP OP
NCL CL OP CL
ODOP OP OP CL
3OP OP CL OP
LCL OP CL CL
TRANSMISSION TEMPERATURE SENSOR
The TRS has an integrated thermistor (Fig. 329)
that the PCM/TCM uses to monitor the transmis-
sion's sump temperature. Since fluid temperature
can affect transmission shift quality and convertor
lock up, the PCM/TCM requires this information to
determine which shift schedule to operate in. The
PCM also monitors this temperature data so it can
energize the vehicle cooling fan(s) when a transmis-
sion ªoverheatº condition exists. If the thermistor cir-
cuit fails, the PCM/TCM will revert to calculated oil
temperature usage.
CALCULATED TEMPERATURE
A failure in the temperature sensor or circuit will
result in calculated temperature being substituted for
actual temperature. Calculated temperature is a pre-
dicted fluid temperature which is calculated from a
combination of inputs:
²Battery (ambient) temperature
²Engine coolant temperature
²In-gear run time since start-up
REMOVAL
(1) Remove valve body assembly from transaxle.
(Refer to 21 - TRANSMISSION/TRANSAXLE/AUTO-
MATIC - 41TE/VALVE BODY - REMOVAL)
(2) Remove transmission range sensor retaining
screw and remove sensor from valve body (Fig. 330).
(3) Remove TRS from manual shaft.
INSTALLATION
(1) Install transmission range sensor (TRS) to the
valve body and torque retaining screw (Fig. 330) to 5
N´m (45 in. lbs.).
(2) Install valve body to transaxle. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
41TE/VALVE BODY - INSTALLATION)
TRD LINK
DESCRIPTION
The Torque Reduction Link (TRD) is a wire
between the PCM and TCM that is used by the TCM
to request torque management. Torque management
controls or reduces torque output of the engine dur-
ing certain shift sequences, reducing torque applied
to the transaxle clutches.
OPERATION
The torque management signal is basically a
12-volt pull-up supplied by the PCM to the TCM over
the torque reduction link (TRD). Torque management
is requested when the TCM pulses this signal to
ground. The PCM recognizes this request and
responds by retarding ignition timing, killing fuel
injectors, etc. The PCM sends a confirmation of the
request to the TCM via the communication bus.
Torque reduction is not noticable by the driver, and
usually lasts for a very short period of time.
If the confirmation signal is not received by the
TCM after two sequential request messages, a diag-
nostic trouble code will be set.
Fig. 330 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
RS41TE AUTOMATIC TRANSAXLE21 - 249
TRANSMISSION RANGE SENSOR (Continued)