2002 CHRYSLER CARAVAN engine

OPERATION
The Transmission Range Sensor (TRS) (Fig. 337)
communicates shift lever position (SLP) to the TCM
as a combination of open and closed switches. Each
shift lever position has an assigned combination of
switch states (open/closed) that the TCM receives
from four sense circuits. The TCM interprets this
information and determines the appropriate trans-
axle gear position and shift schedule.
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 TCM will then determine the shift
lever position based on pressure switch data. This
allows reasonably normal transmission operation
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. 338)
that the TCM uses to monitor the transmission's
sump temperature. Since fluid temperature can
affect transmission shift quality and convertor lock
up, the 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 transmission ªoverheatº
condition exists. If the thermistor circuit fails, the
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. 339).
(3) Remove TRS from manual shaft.
INSTALLATION
(1) Install transmission range sensor (TRS) to the
valve body and torque retaining screw (Fig. 339) 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
Fig. 339 Remove Transmission Range Sensor
1 - TRANSMISSION RANGE SENSOR
2 - MANUAL VALVE CONTROL PIN
3 - RETAINING SCREW
21 - 292 41TE AUTOMATIC TRANSAXLERS
TRANSMISSION RANGE SENSOR (Continued)
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The NV T850 transaxle is available with the 2.4L
Gas and 2.5L Turbo Diesel engine options. Unique
gearing tailored to the performance characteristics of
each engine provides optimum driveability, gradabil-
ity, and acceleration. The gear ratios are as follows:
GEARRATIO (2.4L
Gas)RATIO (2.5L
TD)
1st 3.65 3.46
2nd 2.07 2.05
3rd 1.39 1.37
4th 1.03 0.97
5th 0.83 0.76
Reverse 3.47 3.47
Final Drive
Ratio3.77 3.53
Overall Top
Gear3.12 2.66
TRANSAXLE IDENTIFICATION
NOTE: Since transaxles use unique gear ratios for
each of the two engine applications, it is imperative
that the transaxle is properly identified, and the cor-
rect transaxle assembly number is used when
ordering service parts.The transaxle model, assembly part number, build
date, and final drive ratio (FDR) can be found on a
metal tag fastened to the transaxle case on the bell-
housing (Fig. 2). A barcode label is also glued to the
transaxle bellhousing, and it too includes the trans-
axle part number.
Fig. 2 T850 Transaxle Identification
1 - TRANSAXLE BELLHOUSING
2 - BARCODE LABEL
3 - I.D. TAG
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T850 MANUAL TRANSAXLE (Continued)
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OPERATION
NEUTRAL
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. Since
no synchronizers are engaged on either the input or
intermediate shafts, power is not transmitted to the
intermediate shaft and the differential does not turn
(Fig. 3).
Fig. 3 Neutral Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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1ST GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft first gear is integral to the input shaft,
and is in constant mesh with the intermediate shaft
first speed gear. Because of this constant mesh, the
intermediate shaft first speed gear freewheels until
first gear is selected. As the gearshift lever is moved
to the first gear position, the 1-2 fork moves the 1-2
synchronizer sleeve towards first gear on the inter-
mediate shaft. The synchronizer sleeve engages the
first gear clutch teeth, fixing the gear to the interme-
diate shaft, and allowing power to transmit through
the intermediate shaft to the differential (Fig. 4).
Fig. 4 1st Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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2ND GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft second gear is integral to the input shaft,
and is in constant mesh with the intermediate shaft
second speed gear. Because of this constant mesh,
the intermediate shaft second speed gear freewheels
until second gear is selected. As the gearshift lever is
moved to the second gear position, the 1-2 fork moves
the 1-2 synchronizer sleeve towards second gear on
the intermediate shaft. The synchronizer sleeve
engages the second gear clutch teeth, fixing the gear
to the intermediate shaft, and allowing power to
transmit through the intermediate shaft to the differ-
ential (Fig. 5).
Fig. 5 2nd Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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3RD GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft third speed gear is in constant mesh with
the intermediate shaft 3-4 cluster gear, which is fixed
to the intermediate shaft. Because of this constant
mesh, the input shaft third speed gear freewheels
until third gear is selected. As the gearshift lever is
moved to the third gear position, the 3-4 fork moves
the 3-4 synchronizer sleeve towards third gear on the
input shaft. The synchronizer sleeve engages the
third gear clutch teeth, fixing the gear to the input
shaft, and allowing power to transmit through the
intermediate shaft to the differential (Fig. 6).
Fig. 6 3rd Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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4TH GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft fourth speed gear is in constant mesh
with the intermediate shaft 3-4 cluster gear, which is
fixed to the intermediate shaft. Because of this con-
stant mesh, the input shaft fourth speed gear free-
wheels until fourth gear is selected. As the gearshift
lever is moved to the fourth gear position, the 3-4
fork moves the 3-4 synchronizer sleeve towards
fourth gear on the input shaft. The synchronizer
sleeve engages the fourth gear clutch teeth, fixing
the gear to the input shaft, and allowing power to
transmit through the intermediate shaft to the differ-
ential (Fig. 7).
Fig. 7 4th Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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5TH GEAR
Engine power is transmitted to the input shaft via
the clutch assembly and the input shaft turns. The
input shaft fifth gear is pressed on to the input shaft,
and is in constant mesh with the intermediate shaft
fifth speed gear. Because of this constant mesh, the
intermediate shaft fifth speed gear freewheels until
fifth gear is selected. As the gearshift lever is moved
to the fifth gear position, the 5-R fork moves the 5-R
synchronizer sleeve towards the intermediate shaft
fifth speed gear. The synchronizer sleeve engages the
fifth gear clutch teeth, fixing the gear to the input
shaft, and allowing power to transmit through the
intermediate shaft to the differential (Fig. 8).
Fig. 8 5th Gear Operation
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T850 MANUAL TRANSAXLE (Continued)
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