2003 CHRYSLER CARAVAN engine coolant

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)
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(2) Install injector clip by sliding open end into the
top slot of the injector. The edge of the receiver cup
will slide into the side slots of clip (Fig. 13).
(3) Install injector top end into fuel rail receiver
cap. Be careful not to damage O-ring during installa-
tion (Fig. 13).
(4) Repeat steps for remaining injectors.
(5) Install fuel rail, refer to Fuel Rail in the Fuel
Delivery section.
(6) Connect fuel injector wiring.
(7) Install the Intake Manifold, (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION)
(8) Connect the negative battery cable.
FUEL PUMP RELAY
DESCRIPTION
The fuel pump relay is located in the PDC. The
inside top of the PDC cover has a label showing relay
and fuse location.
OPERATION
The fuel pump relay supplies battery voltage to the
fuel pump. A buss bar in the Power Distribution Cen-
ter (PDC) supplies voltage to the solenoid side and
contact side of the relay. The fuel pump relay power
circuit contains a fuse between the buss bar in the
PDC and the relay. The fuse is located in the PDC.
Refer to the Wiring Diagrams for circuit information.
The PCM controls the fuel pump relay by switch-
ing the ground path for the solenoid side of the relay
on and off. The PCM turns the ground path off when
the ignition switch is in the Off position. When the
ignition switch is in the On position, the PCM ener-
gizes the fuel pump. If the crankshaft position sensor
does not detect engine rotation, the PCM de-ener-
gizes the relay after approximately one second.
IDLE AIR CONTROL MOTOR
DESCRIPTION
The idle air control motor is mounted on the throt-
tle body. The PCM operates the idle air control motor
(Fig. 15) or (Fig. 16).
OPERATION
The PCM adjusts engine idle speed through the
idle air control motor to compensate for engine load,
coolant temperature or barometric pressure changes.
The throttle body has an air bypass passage that
provides air for the engine during closed throttle idle.
The idle air control motor pintle protrudes into the
air bypass passage and regulates air flow through it.The PCM adjusts engine idle speed by moving the
IAC motor pintle in and out of the bypass passage.
The adjustments are based on inputs the PCM
receives. The inputs are from the throttle position
sensor, crankshaft position sensor, coolant tempera-
ture sensor, MAP sensor, vehicle speed sensor and
various switch operations (brake, park/neutral, air
conditioning).
When engine rpm is above idle speed, the IAC is
used for the following functions:
²Off-idle dashpot
Fig. 15 TPS/IAC 2.4L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
Fig. 16 TPS/IAC 3.3/3.8L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
14 - 28 FUEL INJECTIONRS
FUEL INJECTOR (Continued)
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(13) Install right mount bracket to transaxle (Fig.
80).
(14) Connect gearshift cables to shift levers/cover
assembly (Fig. 81). Install cables into position at
mount bracket and secure with retaining clips.
(15) Connect battery cables.
(16) Check transaxle fluid and engine coolant lev-
els. Adjust if necessary. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/MANUAL/FLUID - STANDARD
PROCEDURE)
INSTALLATION - 2.5L TD
(1) Assemble transaxle to engine, while aligning
transaxle input shaft to clutch disc splines.
(2) Install and torque transaxle-to-engine bolts to
95 N´m (70 ft. lbs.) (Fig. 82).
(3) Install transaxle upper mount (Fig. 83). Install
and torque four (4) mount-to-transaxle bolts to 54
N´m (40 ft. lbs.).
(4) Raise transaxle/engine assembly into position
and install upper mount through-bolt. Torque
through-bolt to 75 N´m (55 ft. lbs.).
(5) Remove screw jack.
(6) Connect back-up lamp switch connector.
(7) Install starter motor into position (Fig. 84).
Install and torque bolts to 54 N´m (40 ft. lbs.).
Fig. 80 Transaxle Right Mount and Bracket
1 - MOUNT BRACKET
2 - BOLT (3)
3 - MOUNT
4 - BOLT (1)
Fig. 81 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
21 - 52 T850 MANUAL TRANSAXLERS
T850 MANUAL TRANSAXLE (Continued)
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(15) Install coolant recovery bottle bracket (Fig.
88).
(16) Install coolant recovery bottle to bracket.
(17) Connect battery temperature sensor and
install battery tray (Fig. 89).(18) Install battery, hold-down clamp and nut (Fig.
90).
(19) Install battery thermal shield and clutch cable
eyelet (Fig. 91).
(20) Connect battery cables.
(21) Check transaxle fluid and engine coolant lev-
els. Adjust if necessary. (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/MANUAL/FLUID - STANDARD
PROCEDURE)
Fig. 88 Coolant Recovery Bottle Bracket
1 - COOLANT RECOVERY BOTTLE BRACKET
2 - NUT
3 - MOUNT BRACKET
Fig. 89 Battery Tray
1 - BATTERY TRAY
Fig. 90 Battery and Hold-Down Clamp
1 - BATTERY
2 - HOLD-DOWN CLAMP
Fig. 91 Battery Thermal Shield
1 - BATTERY THERMAL SHIELD
RST850 MANUAL TRANSAXLE21-55
T850 MANUAL TRANSAXLE (Continued)
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(15) Disconnect crossover cable from transaxle
crossover lever (Fig. 142).
(16) Remove crossover cable retainer clip and dis-
engage cable from mount bracket (Fig. 142).
(17) Raise vehicle on hoist.
(18) Remove crossover cable from engine compart-
ment, then remove cable from passenger compart-
ment through opening in floor pan.
INSTALLATION
(1) From underneath vehicle, install gearshift
crossover cable into passenger compartment through
floor pan hole. Install remainder of cable into posi-
tion in engine compartment.
(2) Lower vehicle.
(3) Install crossover cable to mount bracket and
secure with retainer clip (Fig. 143).
(4) Install cable to transaxle crossover lever (Fig.
143).
(5)2.4L Gas models goto Step 10. 2.5L TD
Models:Install coolant recovery bottle bracket (Fig.
144).
Fig. 142 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
Fig. 143 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
Fig. 144 Coolant Recovery Bottle Bracket
1 - COOLANT RECOVERY BOTTLE BRACKET
2 - NUT
3 - MOUNT BRACKET
21 - 76 T850 MANUAL TRANSAXLERS
GEARSHIFT CABLE - CROSSOVER (Continued)
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(17) Raise vehicle on hoist.
(18) Remove selector cable from engine compart-
ment, then remove cable from passenger compart-
ment through opening in floor pan.
INSTALLATION
(1) From underneath vehicle, install gearshift
selector cable into passenger compartment through
floor pan hole. Install remainder of cable into posi-
tion in engine compartment.
(2) Lower vehicle.
(3) Install selector cable to mount bracket and
secure with retainer clip (Fig. 172).
(4) Install cable to transaxle selector lever (Fig.
172).
(5)2.4L Gas models goto Step 10. 2.5L TD
models:Install coolant recovery bottle bracket (Fig.
173).(6) Install coolant recovery bottle to bracket.
(7) Connect battery temperature sensor to battery
tray. Install battery tray into position (Fig. 174).
Fig. 172 Gearshift Cables at Transaxle
1 - SELECTOR CABLE
2 - CABLE RETAINER
3 - CABLE RETAINER
4 - CROSSOVER CABLE
5 - MOUNT BRACKET
Fig. 173 Coolant Recovery Bottle Bracket
1 - COOLANT RECOVERY BOTTLE BRACKET
2 - NUT
3 - MOUNT BRACKET
Fig. 174 Battery Tray
1 - BATTERY TRAY
21 - 84 T850 MANUAL TRANSAXLERS
GEARSHIFT CABLE - SELECTOR (Continued)
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TORQUE CONVERTER CLUTCH (TCC)
In a standard torque converter, the impeller and
turbine are rotating at about the same speed and the
stator is freewheeling, providing no torque multipli-
cation. By applying the turbine's piston to the front
cover's friction material, a total converter engage-
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. 326). 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)TRANSMISSION CONTROL
RELAY
DESCRIPTION
The transmission control relay (Fig. 327) 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.
Fig. 326 Checking Torque Converter Seating
1 - SCALE
2 - STRAIGHTEDGE
RS41TE AUTOMATIC TRANSAXLE21 - 247
TORQUE CONVERTER (Continued)
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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)
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