2005 CHRYSLER CARAVAN automatic transmission

TORQUE CONVERTER
DESCRIPTION
The torque converter (Fig. 321) is a hydraulic
device that couples the engine crankshaft to the
transmission. The torque converter consists of an
outer shell with an internal turbine, a stator, an
overrunning clutch, an impeller and an electronically
applied converter clutch. The converter clutch pro-
vides reduced engine speed and greater fuel economy
when engaged. Clutch engagement also provides
reduced transmission fluid temperatures. The con-
verter clutch engages in third gear. The torque con-
verter hub drives the transmission oil (fluid) pump.
The torque converter is a sealed, welded unit that
is not repairable and is serviced as an assembly.
Fig. 321 Torque Converter Assembly
1 - TURBINE
2 - IMPELLER
3 - HUB
4-STATOR
5 - CONVERTER CLUTCH DISC
6 - DRIVE PLATE
RS41TE AUTOMATIC TRANSAXLE21 - 275

IMPELLER
The impeller (Fig. 322) is an integral part of the
converter housing. The impeller consists of curved
blades placed radially along the inside of the housing
on the transmission side of the converter. As the con-
verter housing is rotated by the engine, so is the
impeller, because they are one and the same and are
the driving member of the system.
Fig. 322 Impeller
1 - ENGINE FLEXPLATE 4 - ENGINE ROTATION
2 - OIL FLOW FROM IMPELLER SECTION INTO TURBINE
SECTION5 - ENGINE ROTATION
3 - IMPELLER VANES AND COVER ARE INTEGRAL
21 - 276 41TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

STATOR
The stator assembly (Fig. 324) is mounted on a sta-
tionary shaft which is an integral part of the oil
pump. The stator is located between the impeller and
turbine within the torque converter case (Fig. 325).
The stator contains an over-running clutch, which
allows the stator to rotate only in a clockwise direc-
tion. When the stator is locked against the over-run-
ning clutch, the torque multiplication feature of the
torque converter is operational.
TORQUE CONVERTER CLUTCH (TCC)
The TCC (Fig. 326) was installed to improve the
efficiency of the torque converter that is lost to the
slippage of the fluid coupling. Although the fluid cou-
pling provides smooth, shock±free power transfer, it
is natural for all fluid couplings to slip. If the impel-
ler and turbine were mechanically locked together, a
zero slippage condition could be obtained. A hydraulic
piston was added to the turbine, and a friction mate-
rial was added to the inside of the front cover to pro-
vide this mechanical lock-up.
OPERATION
The converter impeller (Fig. 327) (driving member),
which is integral to the converter housing and bolted
to the engine drive plate, rotates at engine speed.
The converter turbine (driven member), which reacts
from fluid pressure generated by the impeller, rotates
and turns the transmission input shaft.
TURBINE
As the fluid that was put into motion by the impel-
ler blades strikes the blades of the turbine, some of
the energy and rotational force is transferred into theturbine and the input shaft. This causes both of them
(turbine and input shaft) to rotate in a clockwise
direction following the impeller. As the fluid is leav-
Fig. 324 Stator Components
1 - CAM (OUTER RACE)
2 - ROLLER
3 - SPRING
4 - INNER RACE
Fig. 325 Stator Location
1-STATOR
2 - IMPELLER
3 - FLUID FLOW
4 - TURBINE
Fig. 326 Torque Converter Clutch (TCC)
1 - IMPELLER FRONT COVER
2 - THRUST WASHER ASSEMBLY
3 - IMPELLER
4-STATOR
5 - TURBINE
6 - PISTON
7 - FRICTION DISC
21 - 278 41TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

ment can be obtained. The result of this engagement
is a direct 1:1 mechanical link between the engine
and the transmission.
The engagement and disengagement of the TCC
are automatic and controlled by the Powertrain Con-
trol Module (PCM). The engagement cannot be acti-
vated in the lower gears because it eliminates the
torque multiplication effect of the torque converter
necessary for acceleration. Inputs that determine
clutch engagement are: coolant temperature, vehicle
speed and throttle position. The torque converter
clutch is engaged by the clutch solenoid on the valve
body. The clutch will engage at approximately 56
km/h (35 mph) with light throttle, after the shift to
third gear.
REMOVAL
(1) Remove transmission and torque converter
from vehicle. (Refer to 21 - TRANSMISSION/TRANS-
AXLE/AUTOMATIC - 41TE - REMOVAL)
(2) Place a suitable drain pan under the converter
housing end of the transmission.
CAUTION: Verify that transmission is secure on the
lifting device or work surface, the center of gravity
of the transmission will shift when the torque con-
verter is removed creating an unstable condition.
The torque converter is a heavy unit. Use caution
when separating the torque converter from the
transmission.
(3) Pull the torque converter forward until the cen-
ter hub clears the oil pump seal.
(4) Separate the torque converter from the trans-
mission.
INSTALLATION
Check converter hub and drive notches for sharp
edges, burrs, scratches, or nicks. Polish the hub and
notches with 320/400 grit paper or crocus cloth if nec-
essary. The hub must be smooth to avoid damaging
the pump seal at installation.
(1) Lubricate converter hub and oil pump seal lip
with transmission fluid.
(2) Place torque converter in position on transmis-
sion.
CAUTION: Do not damage oil pump seal or bushing
while inserting torque converter into the front of the
transmission.(3) Align torque converter to oil pump seal open-
ing.
(4) Insert torque converter hub into oil pump.
(5) While pushing torque converter inward, rotate
converter until converter is fully seated in the oil
pump gears.
(6) Check converter seating with a scale and
straightedge (Fig. 329). Surface of converter lugs
should be 1/2 in. to rear of straightedge when con-
verter is fully seated.
(7) If necessary, temporarily secure converter with
C-clamp attached to the converter housing.
(8) Install the transmission in the vehicle. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE - INSTALLATION)
(9) Fill the transmission with the recommended
fluid. (Refer to 21 - TRANSMISSION/TRANSAXLE/
AUTOMATIC - 41TE/FLUID - STANDARD PROCE-
DURE)
Fig. 329 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
21 - 280 41TE AUTOMATIC TRANSAXLERS
TORQUE CONVERTER (Continued)

TRANSMISSION CONTROL
RELAY
DESCRIPTION
The transmission control relay (Fig. 330) is located
in the Intelligent Power Module (IPM), which is
located on the left side of the engine compartment
between the battery and left fender.
OPERATION
The relay is supplied fused B+ voltage, energized by
the PCM/TCM, and is used to supply power to the sole-
noid pack when the transmission is in normal operating
mode. When the relay is ªoffº, no power is supplied to
the solenoid pack and the transmission is in ªlimp-inº
mode. After a controller reset (ignition key turned to the
ªrunº position or after cranking engine), the PCM/TCM
energizes the relay. Prior to this, the PCM/TCM verifies
that the contacts are open by checking for no voltage at
the switched battery terminals. After this is verified,
the voltage at the solenoid pack pressure switches is
checked. After the relay is energized, the PCM/TCM
monitors the terminals to verify that the voltage is
greater than 3 volts.
TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is mounted
to the top of the valve body inside the transaxle andcan only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 331).
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the PCM/TCM.
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the TCM and PCM (Fig. 332).
Fig. 330 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 331 Transmission Range Sensor (TRS)
Location
1 - TRANSMISSION RANGE SENSOR
Fig. 332 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
RS41TE AUTOMATIC TRANSAXLE21 - 281

OPERATION
The Transmission Range Sensor (TRS) (Fig. 331)
communicates shift lever position (SLP) to the PCM/
TCM as a combination of open and closed switches.
Each shift lever position has an assigned combina-
tion of switch states (open/closed) that the PCM/TCM
receives from four sense circuits. The PCM/TCM
interprets this information and determines the
appropriate transaxle gear position and shift sched-
ule.
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. 332)
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. 333).
(3) Remove TRS from manual shaft.
INSTALLATION
(1) Install transmission range sensor (TRS) to the
valve body and torque retaining screw (Fig. 333) to 5
N´m (45 in. lbs.).
(2) Install valve body to transaxle. (Refer to 21 -
TRANSMISSION/TRANSAXLE/AUTOMATIC -
41TE/VALVE BODY - INSTALLATION)
Fig. 333 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
21 - 282 41TE AUTOMATIC TRANSAXLERS
TRANSMISSION RANGE SENSOR (Continued)

VALVE BODY
DESCRIPTION
The valve body assembly consists of a cast alumi-
num valve body, a separator plate, and transfer
plate. The valve body contains valves and check balls
that control fluid delivery to the torque converter
clutch, solenoid/pressure switch assembly, and fric-
tional clutches. The valve body contains the following
components (Fig. 334):
²Regulator valve
²Solenoid switch valve
²Manual valve
²Converter clutch switch valve
²Converter clutch control valve
²Torque converter regulator valve
²Low/Reverse switch valve
In addition, the valve body also contains the ther-
mal valve, #2,3&4 check balls, the #5 (overdrive)
check valve and the 2/4 accumulator assembly. (Refer
to 21 - TRANSMISSION/TRANSAXLE/AUTOMATIC
- 41TE/VALVE BODY - DISASSEMBLY)
OPERATION
NOTE: Refer to the Hydraulic Schematics for a
visual aid in determining valve location, operation
and design.
REGULATOR VALVE
The regulator valve controls hydraulic pressure in
the transaxle. It receives unregulated pressure from
the pump, which works against spring tension to
maintain oil at specific pressures. A system of sleeves
and ports allows the regulator valve to work at one of
three predetermined pressure levels. Regulated oil
pressure is also referred to as ªline pressure.º
SOLENOID SWITCH VALVE
The solenoid switch valve controls line pressure
from the LR/CC solenoid. In one position, it allows
the low/reverse clutch to be pressurized. In the other,
it directs line pressure to the converter control and
converter clutch valves.
Fig. 334 Valve Body Assembly
1 - VALVE BODY 5 - MANUAL VALVE
2 - T/C REGULATOR VALVE 6 - CONVERTER CLUTCH SWITCH VALVE
3 - L/R SWITCH VALVE 7 - SOLENOID SWITCH VALVE
4 - CONVERTER CLUTCH CONTROL VALVE 8 - REGULATOR VALVE
RS41TE AUTOMATIC TRANSAXLE21 - 283

MANUAL VALVE
The manual valve is operated by the mechanical
shift linkage. Its primary responsibility is to send
line pressure to the appropriate hydraulic circuits
and solenoids. The valve has three operating ranges
or positions.
CONVERTER CLUTCH SWITCH VALVE
The main responsibility of the converter clutch
switch valve is to control hydraulic pressure applied
to the front (off) side of the converter clutch piston.
Line pressure from the regulator valve is fed to the
torque converter regulator valve, where it passes
through the valve, and is slightly regulated. The
pressure is then directed to the converter clutch
switch valve and to the front side of the converter
clutch piston. This pressure pushes the piston back
and disengages the converter clutch.
CONVERTER CLUTCH CONTROL VALVE
The converter clutch control valve controls the
back (on) side of the torque converter clutch. When
the PCM/TCM energizes or modulates the LR/CC
solenoid to apply the converter clutch piston, both
the converter clutch control valve and the converter
control valve move, allowing pressure to be applied to
the back side of the clutch.
T/C REGULATOR VALVE
The torque converter regulator valve slightly regu-
lates the flow of fluid to the torque converter.
LOW/REVERSE SWITCH VALVE
The low/reverse clutch is applied from different
sources, depending on whether low (1st) gear or
reverse is selected. The low/reverse switch valve
alternates positions depending on from which direc-
tion fluid pressure is applied. By design, when the
valve is shifted by fluid pressure from one channel,
the opposing channel is blocked. The switch valve
alienates the possibility of a sticking ball check, thus
providing consistent application of the low/reverse
clutch under all operating conditions.
REMOVAL
NOTE: If valve body is replaced or reconditioned,
the ªQuick-Learnº Procedure must be performed.
(Refer to 8 - ELECTRICAL/ELECTRONIC CONTROLMODULES/TRANSMISSION CONTROL MODULE -
STANDARD PROCEDURE)
(1) Disconnect battery negative cable.
(2) Disconnect gearshift cable from manual valve
lever.
(3) Remove manual valve lever from manual shaft.
(4) Raise vehicle on hoist.
(5) Remove oil pan bolts (Fig. 335).
(6) Remove oil pan (Fig. 336).
Fig. 335 Oil Pan Bolts
1 - OIL PAN BOLTS (USE RTV UNDER BOLT HEADS)
Fig. 336 Oil Pan
1 - OIL PAN
2 - 1/8 INCH BEAD OF RTV SEALANT
3 - OIL FILTER
21 - 284 41TE AUTOMATIC TRANSAXLERS
VALVE BODY (Continued)