2002 CHRYSLER CARAVAN relay

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. 14) or (Fig. 15).
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, crank-
shaft position sensor, coolant temperature sensor, MAP
sensor, vehicle speed sensor and various switch opera-
tions (brake, park/neutral, air conditioning).
When engine rpm is above idle speed, the IAC is
used for the following functions:
²Off-idle dashpot
²Deceleration air flow control
²A/C compressor load control (also opens the pas-
sage slightly before the compressor is engaged so
that the engine rpm does not dip down when the
compressor engages)
Target Idle
Target idle is determined by the following inputs:
²Gear position
²ECT Sensor
²Battery voltage
²Ambient/Battery Temperature Sensor
²VSS
²TPS
²MAP Sensor
Fig. 14 TPS/IAC 2.4L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
Fig. 15 TPS/IAC 3.3/3.8L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
RSFUEL INJECTION14-27
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The downstream heated oxygen sensor threads into
the outlet pipe at the rear of the catalytic convertor
(Fig. 22).
OPERATION
A single sensor ground is used for all O2 sensors (2
senors on 4 cyl. vehicles and 4 sensors on 6 cyl. vehi-
cles).
As vehicles accumulate mileage, the catalytic con-
vertor deteriorates. The deterioration results in a
less efficient catalyst. To monitor catalytic convertor
deterioration, the fuel injection system uses two
heated oxygen sensors. One sensor upstream of the
catalytic convertor, one downstream of the convertor.
The PCM compares the reading from the sensors to
calculate the catalytic convertor oxygen storage
capacity and converter efficiency. Also, the PCM uses
the upstream heated oxygen sensor input when
adjusting injector pulse width.
When the catalytic converter efficiency drops below
emission standards, the PCM stores a diagnostic
trouble code and illuminates the malfunction indica-
tor lamp (MIL).
The O2 sensors produce voltages from 0 to 1 volt,
depending upon the oxygen content of the exhaust
gas. When a large amount of oxygen is present
(caused by a lean air/fuel mixture, can be caused by
misfire and exhaust leaks), the sensors produces a
low voltage. When there is a lesser amount of oxygen
present (caused by a rich air/fuel mixture, can be
caused by internal engine problems) it produces a
higher voltage. By monitoring the oxygen content
and converting it to electrical voltage, the sensors act
as a rich-lean switch.The oxygen sensors are equipped with a heating
element that keeps the sensors at proper operating
temperature during all operating modes. Maintaining
correct sensor temperature at all times allows the
system to enter into closed loop operation sooner.
Also, it allows the system to remain in closed loop
operation during periods of extended idle.
In Closed Loop operation the PCM monitors the O2
sensors input (along with other inputs) and adjusts
the injector pulse width accordingly. During Open
Loop operation the PCM ignores the O2 sensor input.
The PCM adjusts injector pulse width based on pre-
programmed (fixed) values and inputs from other
sensors.
The Automatic Shutdown (ASD) relay supplies bat-
tery voltage to both the upstream and downstream
heated oxygen sensors. The oxygen sensors are
equipped with a heating element. The heating ele-
ments reduce the time required for the sensors to
reach operating temperature. The PCM uses pulse
width modulation to control the ground side of the
heater to regulate the temperature on 4 cyl.
upstream O2 heater only. All other 4 cyl. and 6 cyl.
O2 heaters do not use pulse width modulation.
UPSTREAM OXYGEN SENSOR
The input from the upstream heated oxygen sensor
tells the PCM the oxygen content of the exhaust gas.
Based on this input, the PCM fine tunes the air-fuel
ratio by adjusting injector pulse width.
The sensor input switches from 0 to 1 volt, depend-
ing upon the oxygen content of the exhaust gas in
the exhaust manifold. When a large amount of oxy-
gen is present (caused by a lean air-fuel mixture), the
sensor produces voltage as low as 0.1 volt. When
there is a lesser amount of oxygen present (rich air-
fuel mixture) the sensor produces a voltage as high
as 1.0 volt. By monitoring the oxygen content and
converting it to electrical voltage, the sensor acts as
a rich-lean switch.
The heating element in the sensor provides heat to
the sensor ceramic element. Heating the sensor
allows the system to enter into closed loop operation
sooner. Also, it allows the system to remain in closed
loop operation during periods of extended idle.
In Closed Loop, the PCM adjusts injector pulse
width based on the upstream heated oxygen sensor
input along with other inputs. In Open Loop, the
PCM adjusts injector pulse width based on prepro-
grammed (fixed) values and inputs from other sen-
sors.
DOWNSTREAM OXYGEN SENSOR
The downstream heated oxygen sensor input is
used to detect catalytic convertor deterioration. As
the convertor deteriorates, the input from the down-
Fig. 22 O2 SENSOR DOWNSTREAM 1/2 - 2.4/3.3/
3.8L
RSFUEL INJECTION14-31
O2 SENSOR (Continued)
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FUEL SYSTEM
TABLE OF CONTENTS
page page
FUEL SYSTEM 2.5L TURBO DIESEL
DESCRIPTION - DIESEL FUEL DELIVERY
SYSTEM.............................1
WARNING - HIGH FUEL SYSTEM PRESSURE . . 1
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AIR IN FUEL
SYSTEM.............................1
DIAGNOSIS AND TESTING - FUEL SUPPLY
RESTRICTIONS........................1
STANDARD PROCEDURE
STANDARD PROCEDURES - DRAINING
WATER FROM FUEL FILTER..............2STANDARD PROCEDURE - FUEL SYSTEM
AIR PURGE...........................2
STANDARD PROCEDURES - CLEANING
FUEL SYSTEM COMPONENTS............2
SPECIFICATIONS - TORQUE...............3
FUEL DELIVERY..........................4
FUEL INJECTION........................11
FUEL SYSTEM 2.5L TURBO
DIESEL
DESCRIPTION - DIESEL FUEL DELIVERY
SYSTEM
The fuel system on the 2.5L Common Rail Diesel
Engine uses a fuel injection pump and an Electronic
Control Module (ECM).
The fuel delivery system consists of the:
²Accelerator pedal
²Air cleaner housing/element
²Fuel filter/water separator
²Fuel heater
²Fuel heater relay
²Fuel transfer (lift) pump
²Fuel injection pump
²Fuel injectors
²Fuel tank
²Fuel tank filler/vent tube assembly
²Fuel tank filler tube cap
²Fuel tank module containing the rollover valve
and a fuel gauge sending unit (fuel level sensor).
²Fuel tubes/lines/hoses
²High-pressure fuel injector lines
²Low-pressure fuel supply lines
²Low-pressure fuel return line
²Overflow valve
²Quick-connect fittings
²Water draining
WARNING - HIGH FUEL SYSTEM PRESSURE
WARNING:: THE INJECTION PUMP SUPPLIES HIGH-
PRESSURE FUEL TO EACH INDIVIDUAL INJECTOR
THROUGH HIGH-PRESSURE LINES. FUEL UNDERTHIS AMOUNT OF PRESSURE CAN PENETRATE
SKIN AND CAUSE PERSONAL INJURY. WEAR
SAFETY GOGGLES AND ADEQUATE PROTECTIVE
CLOTHING. AVOID CONTACT WITH FUEL SPRAY
WHEN BLEEDING HIGH-PRESSURE FUEL LINES.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - AIR IN FUEL
SYSTEM
Air will enter the fuel system whenever fuel supply
lines, separator filters, injection pump, high-pressure
lines or injectors are removed or disconnected. Air
trapped in the fuel system can result in hard start-
ing, a rough running engine, engine misfire, low
power, excessive smoke and fuel knock. After service
is performed, air must be bled from the system
before starting the engine.
Inspect the fuel system from the fuel tank to the
injectors for loose connections. Leaking fuel is an
indicator of loose connections or defective seals. Air
can also enter the fuel system between the fuel tank
and the transfer pump. Inspect the fuel tank and fuel
lines for damage that might allow air into the sys-
tem.
DIAGNOSIS AND TESTING - FUEL SUPPLY
RESTRICTIONS
LOW-PRESSURE LINES
Fuel supply line restrictions or a defective fuel
transfer pump can cause starting problems and pre-
vent engine from accelerating. The starting problems
include; low power and/or white fog like exhaust.
RGFUEL SYSTEM14a-1
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MASS AIR FLOW (MAF)
SENSOR
DESCRIPTION
The Mass Air Flow (MAF) Sensor is mounted
inline in the air intake between the air filter and the
turbocharger (Fig. 8).
OPERATION
The ECM uses the mass air flow (MAF) sensor to
measure air density. The MAF sensor contains a
ceramic element. A signal voltage is provided to the
element. As engine speed increases, airflow across
the ceramic element increases. Changes in air flow
and air density cause the temperature of the ceramic
element to fluxuate. The ceramic element changes
resistance respectively to changes in temperature.
The change in resistance varies the signal voltage
output to the ECM. The diesel power relay supplies
battery power the to MAF sensor. Ground is providedby the ECM. The MAF sensor signal is provided by
the ECM.
REMOVAL
(1) Disconnect negative battery cable.
(2) Disconnect MAF sensor electrical connector
(Fig. 9).
(3) Loosen MAF sensor retaining clamps (Fig. 9).
(4) Remove MAF sensor from airduct (Fig. 9).
INSTALLATION
(1) Install MAF sensor in airduct (Fig. 9).
(2) Tighten retaining clamps (Fig. 9).
(3) Connect MAF sensor electrical connector (Fig.
9).
(4) Connect negative battery cable.
Fig. 8 MASS AIR FLOW (MAF) SENSOR
Fig. 9 MASS AIR FLOW (MAF) SENSOR LOCATION
1 - MAF SENSOR ELECTRICAL CONNECTOR
2 - RETAINING CLAMPS
3 - MASS AIR FLOW (MAF) SENSOR
4 - AIR CLEANER HOUSING
14a - 16 FUEL INJECTIONRG
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CONDITION POSSIBLE CAUSES CORRECTION
GROWLING, GRATING OR
SCRAPING NOISES1. Drive Plate Broken. 1. Replace.
2. Torque Converter Bolts Hitting
Dust Shield.2. Dust shield bent. Replace or repair.
3. Planetary Gear Set Broken/
Seized.3. Check for debris in oil pan and repair as
required.
4. Overrunning Clutch Worn/Broken. 4. Inspect and check for debris in oil pan.
Repair as required.
5. Oil Pump Components Scored/
Binding.5. Remove, inspect and repair as required.
6. Output Shaft Bearing or Bushing
Damaged.6. Remove, inspect and repair as required.
7. Clutch Operation Faulty. 7. Perform air pressure check and repair as
required.
8. Front and Rear Bands
Misadjusted.8. Adjust bands.
DRAGS OR LOCKS UP 1. Fluid Level Low. 1. Check and adjust level.
2. Clutch Dragging/Failed 2. Air pressure check clutch operation and
repair as required.
3. Front or Rear Band Misadjusted. 3. Adjust bands.
4. Case Leaks Internally. 4. Check for leakage between passages in
case.
5. Servo Band or Linkage
Malfunction.5. Air pressure check servo operation and
repair as required.
6. Overrunning Clutch Worn. 6. Remove and inspect clutch. Repair as
required.
7. Planetary Gears Broken. 7. Remove, inspect and repair as required
(look for debris in oil pan).
WHINE/NOISE RELATED
TO ENGINE SPEED1. Fluid Level Low. 1. Add fluid and check for leaks.
2. Shift Cable Incorrect Routing. 2. Check shift cable for correct routing.
Should not touch engine or bell housing.
TORQUE CONVERTER
LOCKS UP IN SECOND
AND/OR THIRD GEARLockup Solenoid, Relay or Wiring
Shorted/Open.Test solenoid, relay and wiring for
continuity, shorts or grounds. Replace
solenoid and relay if faulty. Repair wiring
and connectors as necessary.
HARSH 1-2 OR 2-3
SHIFTSLockup Solenoid Malfunction. Remove valve body and replace solenoid
assembly.
NO START IN PARK OR
NEUTRAL1. Gearshift Linkage/Cable
Misadjusted.1. Adjust linkage/cable.
2. Neutral Switch Wire Open/Cut. 2. Check continuity with test lamp. Repair
as required.
3. Neutral Switch Faulty. 3. Refer to service section for test and
replacement procedure.
4. Neutral Switch Connect Faulty. 4. Connectors spread open. Repair.
5. Valve Body Manual Lever
Assembly Bent/Worn/Broken.5. Inspect lever assembly and replace if
damaged.
21 - 30 31TH AUTOMATIC TRANSAXLERS
31TH AUTOMATIC TRANSAXLE (Continued)
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41TE AUTOMATIC TRANSAXLE
TABLE OF CONTENTS
page page
41TE AUTOMATIC TRANSAXLE
DESCRIPTION........................162
OPERATION..........................164
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - 41TE
TRANSAXLE GENERAL DIAGNOSIS......164
DIAGNOSIS AND TESTING - ROAD TEST . . 165
DIAGNOSIS AND TESTING - HYDRAULIC
PRESSURE TESTS...................165
DIAGNOSIS AND TESTING - CLUTCH AIR
PRESSURE TESTS...................168
DIAGNOSIS AND TESTING - TORQUE
CONVERTER HOUSING FLUID LEAKAGE . . 168
REMOVAL............................169
DISASSEMBLY........................171
ASSEMBLY...........................190
INSTALLATION........................213
SCHEMATICS AND DIAGRAMS
41TE TRANSAXLE HYDRAULIC
SCHEMATICS.......................216
SPECIFICATIONS - 41TE TRANSAXLE......228
SPECIAL TOOLS
41TE AUTOMATIC TRANSAXLE.........230
ACCUMULATOR
DESCRIPTION........................236
OPERATION..........................236
AUTOSTICK SWITCH
DESCRIPTION........................237
OPERATION..........................237
DRIVING CLUTCHES
DESCRIPTION........................237
OPERATION..........................238
FINAL DRIVE
DISASSEMBLY........................238
ASSEMBLY...........................243
ADJUSTMENTS
ADJUSTMENT - DIFFERENTIAL BEARING
PRELOAD..........................246
FLUID
STANDARD PROCEDURE
FLUID LEVEL AND CONDITION CHECK . . . 249
STANDARD PROCEDURE - FLUID AND
FILTER SERVICE.....................250
GEAR SHIFT CABLE
REMOVAL............................251
INSTALLATION........................253
ADJUSTMENTS
GEARSHIFT CABLE ADJUSTMENT.......254
HOLDING CLUTCHES
DESCRIPTION........................255OPERATION..........................255
INPUT CLUTCH ASSEMBLY
DISASSEMBLY........................255
ASSEMBLY...........................263
OIL PUMP
DESCRIPTION........................272
OPERATION..........................272
STANDARD PROCEDURE - OIL PUMP
VOLUME CHECK.....................272
DISASSEMBLY........................273
ASSEMBLY...........................274
PLANETARY GEARTRAIN
DESCRIPTION........................274
OPERATION..........................274
SEAL - OIL PUMP
REMOVAL............................275
INSTALLATION........................275
SHIFT INTERLOCK SOLENOID
DESCRIPTION........................275
OPERATION..........................276
DIAGNOSIS AND TESTING - BRAKE/
TRANSMISSION SHIFT INTERLOCK
SOLENOID..........................277
REMOVAL............................277
INSTALLATION........................278
SOLENOID/PRESSURE SWITCH ASSY
DESCRIPTION........................279
OPERATION..........................280
REMOVAL............................280
INSTALLATION........................281
SPEED SENSOR - INPUT
DESCRIPTION........................281
OPERATION..........................282
REMOVAL............................282
INSTALLATION........................283
SPEED SENSOR - OUTPUT
DESCRIPTION........................283
OPERATION..........................283
REMOVAL............................284
INSTALLATION........................284
TORQUE CONVERTER
DESCRIPTION........................285
OPERATION..........................289
REMOVAL............................290
INSTALLATION........................290
TRANSMISSION CONTROL RELAY
DESCRIPTION........................291
OPERATION..........................291
TRANSMISSION RANGE SENSOR
DESCRIPTION........................291
RS41TE AUTOMATIC TRANSAXLE21 - 161
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OPERATION..........................292
REMOVAL............................292
INSTALLATION........................292
TRD LINK
DESCRIPTION........................292
OPERATION..........................292
VALVE BODY
DESCRIPTION........................293OPERATION..........................293
REMOVAL
REMOVAL..........................294
REMOVAL..........................296
DISASSEMBLY........................297
ASSEMBLY...........................301
INSTALLATION........................306
41TE AUTOMATIC
TRANSAXLE
DESCRIPTION
The 41TE (Fig. 1) is a four-speed transaxle that is
a conventional hydraulic/mechanical assembly with
an integral differential, and is controlled with adap-
tive electronic controls and monitors. The hydraulic
system of the transaxle consists of the transaxle
fluid, fluid passages, hydraulic valves, and various
line pressure control components. An input clutch
assembly which houses the underdrive, overdrive,
and reverse clutches is used. It also utilizes separate
holding clutches: 2nd/4th gear and Low/Reverse. The
primary mechanical components of the transaxle con-
sist of the following:
²Three multiple disc input clutches
²Two multiple disc holding clutches
²Four hydraulic accumulators
²Two planetary gear sets
²Hydraulic oil pump²Valve body
²Solenoid/Pressure switch assembly
²Integral differential assembly
Control of the transaxle is accomplished by fully
adaptive electronics. Optimum shift scheduling is
accomplished through continuous real-time sensor
feedback information provided to the Transmission
Control Module (TCM).
The TCM is the heart of the electronic control sys-
tem and relies on information from various direct
and indirect inputs (sensors, switches, etc.) to deter-
mine driver demand and vehicle operating condi-
tions. With this information, the TCM can calculate
and perform timely and quality shifts through vari-
ous output or control devices (solenoid pack, trans-
mission control relay, etc.).
The TCM also performs certain self-diagnostic
functions and provides comprehensive information
(sensor data, DTC's, etc.) which is helpful in proper
diagnosis and repair. This information can be viewed
with the DRB scan tool.
21 - 162 41TE AUTOMATIC TRANSAXLERS
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OPERATION
SOLENOIDS
The solenoids receive electrical power from the
Transmission Control Relay through a single wire.
The TCM energizes or operates the solenoids individ-
ually by grounding the return wire of the solenoid
needed. When a solenoid is energized, the solenoid
valve shifts, and a fluid passage is opened or closed
(vented or applied), depending on its default operat-
ing state. The result is an apply or release of a fric-
tional element.
The 2/4 and UD solenoids are normally applied,
which by design allow fluid to pass through in their
relaxed or ªoffº state. This allows transaxle limp-in
(P,R,N,2) in the event of an electrical failure.
The continuity of the solenoids and circuits are
periodically tested. Each solenoid is turned on or off
depending on its current state. An inductive spike
should be detected by the TCM during this test. It no
spike is detected, the circuit is tested again to verify
the failure. In addition to the periodic testing, the
solenoid circuits are tested if a speed ratio or pres-
sure switch error occurs.
PRESSURE SWITCHES
The TCM relies on three pressure switches to mon-
itor fluid pressure in the L/R, 2/4, and OD hydraulic
circuits. The primary purpose of these switches is to
help the TCM detect when clutch circuit hydraulic
failures occur. The range for the pressure switch clos-
ing and opening points is 11-23 psi. Typically the
switch opening point will be approximately one psi
lower than the closing point. For example, a switch
may close at 18 psi and open at 17 psi. The switches
are continuously monitored by the TCM for the cor-
rect states (open or closed) in each gear as shown in
the following chart:
PRESSURE SWITCH STATES
GEAR L/R 2/4 OD
ROPOPOP
P/N CL OP OP
1st CL OP OP
2nd OP CL OP
DOPOPCL
OD OP CL CL
OP = OPEN
CL = CLOSED
A Diagnostic Trouble Code (DTC) will set if the
TCM senses any switch open or closed at the wrong
time in a given gear.The TCM also tests the 2/4 and OD pressure
switches when they are normally off (OD and 2/4 are
tested in 1st gear, OD in 2nd gear, and 2/4 in 3rd
gear). The test simply verifies that they are opera-
tional, by looking for a closed state when the corre-
sponding element is applied. Immediately after a
shift into 1st, 2nd, or 3rd gear with the engine speed
above 1000 rpm, the TCM momentarily turns on ele-
ment pressure to the 2/4 and/or OD clutch circuits to
identify that the appropriate switch has closed. If it
doesn't close, it is tested again. If the switch fails to
close the second time, the appropriate Diagnostic
Trouble Code (DTC) will set.
REMOVAL
NOTE: If solenoid/pressure switch assembly is
being replaced, it is necessary to perform the TCM
Quick Learn Procedure. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/TRANSMISSION
CONTROL MODULE - STANDARD PROCEDURE)
(1) Disconnect battery negative cable.
(2) Remove air cleaner assembly.
(3) Disconnect solenoid/pressure switch assembly
connector.
(4) Disconnect input speed sensor connector.
(5) Remove input speed sensor (Fig. 314).
Fig. 314 Input Speed Sensor
1 - INPUT SPEED SENSOR
21 - 280 41TE AUTOMATIC TRANSAXLERS
SOLENOID/PRESSURE SWITCH ASSY (Continued)
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