2003 CHRYSLER CARAVAN reset

8W-97 POWER DISTRIBUTION SYSTEM
TABLE OF CONTENTS
page page
POWER DISTRIBUTION SYSTEM
DESCRIPTION..........................1
OPERATION............................1
SPECIAL TOOLS
POWER DISTRIBUTION SYSTEMS.........2
ACCESSORY RELAY
DESCRIPTION..........................2
OPERATION............................2
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - ACCESSORY
RELAY...............................2
REMOVAL.............................3
INSTALLATION..........................3
INTEGRATED POWER MODULE
DESCRIPTION..........................3OPERATION............................3
REMOVAL.............................4
INSTALLATION..........................4
IOD FUSE
DESCRIPTION..........................4
OPERATION............................5
REMOVAL.............................5
INSTALLATION..........................5
POWER OUTLET
DESCRIPTION..........................5
OPERATION............................5
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER OUTLET . . 6
REMOVAL.............................6
INSTALLATION..........................6
POWER DISTRIBUTION
SYSTEM
DESCRIPTION
This group covers the various standard and
optional power distribution components used on this
model. The power distribution system for this vehicle
consists of the following components:
²Integrated Power Module (IPM)
²Front Control Module (FCM)
²Power Outlets
Refer to Wiring Diagrams for complete circuit sche-
matics.
The power distribution system also incorporates
various types of circuit control and protection fea-
tures, including:
²Automatic resetting circuit breakers
²Blade-type fuses
²Bus bars
²Cartridge fuses
²Circuit splice blocks
²Flashers
²Fusible links
²RelaysFollowing are general descriptions of the major
components in the power distribution system. See the
owner's manual in the vehicle glove box for more
information on the features and use of all of the
power distribution system components.
OPERATION
The power distribution system for this vehicle is
designed to provide safe, reliable, and centralized dis-
tribution points for the electrical current required to
operate all of the many standard and optional facto-
ry-installed electrical and electronic powertrain,
chassis, safety, security, comfort and convenience sys-
tems. At the same time, the power distribution sys-
tem was designed to provide ready access to these
electrical distribution points for the vehicle techni-
cian to use when conducting diagnosis and repair of
faulty circuits. The power distribution system can
also prove useful for the sourcing of additional elec-
trical circuits that may be required to provide the
electrical current needed to operate many accessories
that the vehicle owner may choose to have installed
in the aftermarket.
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-1
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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
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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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opposite preset limit or switch point. The process
then repeats itself in the opposite direction.
Short term fuel correction will keep increasing or
decreasing injector pulse-width based upon the
upstream O2 Sensor input. The maximum range of
authority for short term memory is 25% (+/-) of base
pulse-width. Short term is violated and is lost when
ignition is turned OFF.
Long Term
The second fuel correction program is the long
term adaptive memory. In order to maintain correct
emission throughout all operating ranges of the
engine, a cell structure based on engine rpm and load
(MAP) is used.
Ther number of cells varies upon the driving con-
ditions. Two cells are used only during idle, based
upon TPS and Park/Neutral switch inputs. There
may be two other cells used for deceleration, based
on TPS, engine rpm, and vehicle speed. The other
twelve cells represent a manifold pressure and an
rpm range. Six of the cells are high rpm and the
other six are low rpm. Each of these cells has a spe-
cific MAP voltage range Typical Adaptive Memory
Fuel Cells .As the engine enters one of these cells the PCM
looks at the amount of short term correction being
used. Because the goal is to keep short term at 0 (O2
Sensor switching at 0.5 volt), long term will update
in the same direction as short term correction was
moving to bring the short term back to 0. Once short
term is back at 0, this long term correction factor is
stored in memory.
The values stored in long term adaptive memory
are used for all operating conditions, including open
loop and cold starting. However, the updating of the
long term memory occurs after the engine has
exceeded approximately 170É-190É F, with fuel control
in closed loop and two minutes of engine run time.
This is done to prevent any transitional temperature
or start-up compensations from corrupting long term
fuel correction.
Long term adaptive memory can change the pulse-
width by as much as 25%, which means it can correct
for all of short term. It is possible to have a problem
that would drive long term to 25% and short term to
another 25% for a total change of 50% away from
base pulse-width calculation.
TYPICAL ADAPTIVE MEMORY FUEL CELLS
Open
ThrottleOpen
ThrottleOpen
ThrottleOpen
ThrottleOpen
ThrottleOpen
Throttle Idle Decel
Vacuum 20 17 13 9 5 0
Above 1,984
rpm1 3 5 7 9 11 13 Drive 15
Below 1,984
rpm02 4 6 8 1012
Neutral14
MAP volt =0 1.4 2.0 2.6 3.3 3.9
Fuel Correction Diagnostics
There are two fuel correction diagnostic routines:
²Fuel System Rich
²Fuel System Lean
A DTC is set and the MIL is illuminated if the
PCM detects either of these conditions. This is deter-
mined based on total fuel correction, short term
times long term.
PROGRAMMABLE COMMUNICATIONS
INTERFACE (PCI) BUS
DESCRIPTION
The Programmable Communication Interface Mul-
tiplex system (PCI Bus) consist of a single wire. The
Body Control Module (BCM) acts as a splice to con-
nect each module and the Data Link Connector(DLC) together. Each module is wired in parallel to
the data bus through its PCI chip set and uses its
ground as the bus reference. The wiring is a mini-
mum 20 gage wire.
OPERATION
Various modules exchange information through a
communications port called the PCI Bus. The Power-
train Control Module (PCM) transmits the Malfunc-
tion Indicator Lamp (Check Engine) On/Off signal
and engine RPM on the PCI Bus. The PCM receives
the Air Conditioning select input, transaxle gear
position inputs over the PCI Bus. The PCM also
receives the air conditioning evaporator temperature
signal from the PCI Bus.
The following components access or send informa-
tion on the PCI Bus.
RSFUEL INJECTION14-21
FUEL INJECTION (Continued)
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ADJUSTMENT
(1) Park the vehicle on level ground and set the
parking brake.
(2) Place the gearshift lever in gated park (P) and
remove ignition key.
(3) Loosen the cable adjustment screw at the
transaxle manual valve lever (Fig. 223).
(4) Pull the gearshift lever fully forward to the
park detent position.
(5) Release the park brake, then rock the vehicle
to assure it is in park. Reset the park brake.
(6) Tighten the cable adjustment screw to 8 N´m
(70 in. lbs.). Gearshift cable should now be properly
adjusted.
(7) Verify adjustment by using the verification pro-
cedure.
HOLDING CLUTCHES
DESCRIPTION
Two hydraulically applied multi-disc clutches are
used to hold planetary geartrain components station-
ary while the input clutches drive others. The 2/4
and Low/Reverse clutches are considered holding
clutches and are contained at the rear of the trans-
axle case. (Fig. 224).
OPERATION
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.
2/4 CLUTCH
The 2/4 clutch is hydraulically applied in second
and fourth gears by pressurized fluid against the 2/4
clutch piston. When the 2/4 clutch is applied, the
front sun gear assembly is held or grounded to the
transaxle case.
LOW/REVERSE CLUTCH
The Low/Reverse clutch is hydraulically applied in
park, reverse, neutral, and first gears by pressurized
fluid against the Low/Reverse clutch piston. When
the Low/Reverse clutch is applied, the front planet
carrier/rear annulus assembly is held or grounded to
the transaxle case.
Fig. 223 Gearshift Cable Adjustment
1 - GEARSHIFT CABLE ADJUSTMENT SCREW
2 - GEARSHIFT CABLE
Fig. 224 2/4 and Low/Reverse Clutches
1 - FRONT PLANET CARRIER/REAR ANNULUS
2 - 2/4 CLUTCH
3 - L/R CLUTCH
4 - REAR PLANET CARRIER/FRONT ANNULUS
5 - REAR SUN GEAR
6 - FRONT SUN GEAR ASSEMBLY
RS41TE AUTOMATIC TRANSAXLE21 - 207
GEAR SHIFT CABLE (Continued)
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OPERATION
The relay is supplied fused B+ voltage, energized
by the PCM/TCM, and is used to supply power to the
solenoid 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 bat-
tery 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 and
can only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 328).
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. 329).
OPERATION
The Transmission Range Sensor (TRS) (Fig. 328)
communicates shift lever position (SLP) to the PCM/
TCM as a combination of open and closed switches.
Each shift lever position has an assigned combination
of switch states (open/closed) that the PCM/TCM
receives from four sense circuits. The PCM/TCM inter-
prets this information and determines the appropriate
transaxle gear position and shift schedule.
Fig. 327 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 328 Transmission Range Sensor (TRS)
Location
1 - TRANSMISSION RANGE SENSOR
Fig. 329 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
21 - 248 41TE AUTOMATIC TRANSAXLERS
TRANSMISSION CONTROL RELAY (Continued)
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(4) Install andlightly tightenthe three remain-
ing wheel mounting nuts, securing the wheel cover in
place (Fig. 12).
(5) Progressively tighten all five wheel mounting
nuts in the proper sequence (Fig. 16). Tighten wheel
nuts to a torque of 135 N´m (100 ft. lbs.).
(6) Lower the vehicle.
TIRE PRESSURE MONITORING
DESCRIPTION
Some versions of this vehicle are equipped with a
Tire Pressure Monitoring (TPM) system. It monitors
air pressure in the four road tires (excludes spare).
Pressure in the spare tire is not monitored.
There is a sensor (transmitter) in each of the vehi-
cle's four road wheels. The system alerts the driver
when tire pressure falls outside predetermined
thresholds (pressure too low or too high). A message
is then displayed on the Electronic Vehicle Informa-
tion Center (EVIC) located in the overhead console.
For further information, refer to the Owners Man-
ual or the appropriate diagnostic information.
OPERATION
The Tire Pressure Monitoring (TPM) system uses
radio and sensor technology to monitor tire air pres-
sure levels. Sensors, mounted to each road wheel as
part of the valve stem, transmit tire pressure read-
ings to a receiver located in the overhead console.
These transmissions occur once every minute at
speeds over 20 mph (32 km/h). The Tire Pressure
Monitoring system remains active even if no tire
pressure related message is displayed in the EVIC.
If any road tire pressure has exceeded the low or
high pressure threshold (refer to chart below), the
TPM system will display a message in the EVIC and
sound a chime. This message will be displayed for
the rest of the ignition cycle, or until either the Low/
High Tire pressure condition has been corrected. If
the C/T, MENU, STEP or RESET button is pressed,
the message is replaced by the new message
requested; however, if the Low/High Tire condition
has not been corrected, the Low/High Tire pressure
message will again be displayed.
Fig. 14 TWO WHEEL MOUNTING NUTS INSTALLED
1 - WHEEL
2 - VALVE STEM
3 - HUB PILOT
4 - NUTS
Fig. 15 WHEEL COVER INSTALLATION OVER TWO
NUTS
1 - RETAINING TABS
2 - VALVE STEM
3 - BOLT-ON WHEEL COVER
Fig. 16 NUT TIGHTENING SEQUENCE
RSTIRES/WHEELS22-9
TIRES/WHEELS (Continued)
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CAUTION: Never attempt to train more than one
vehicle at a time. System is capable of reading tire
pressure sensor transmissions from other near-by
vehicles.
Each time a wheel rotation or tire pressure sensor
replacement occurs the tire pressure sensors must be
retrained. This is necessary to inform the Electronic
Vehicle Information Center (EVIC) that a sensor
change was made and where. Retraining is accom-
plished through the EVIC used in conjunction with a
Re-learn Magnet, Special Tool 8821.
NOTE: Use the following procedure to retrain all
four (4) road wheel tire pressure sensors. No
attempt should be made to retrain individual sen-
sors.
(1) Retrieve Re-learn Magnet, Special Tool 8821.
(2) Press MENU Button on EVIC until9RETRAIN
TIRE SENSORS - NO9is displayed.
(3) Press STEP button to select9YES9.
NOTE: There is a 60 second timer for training the
first sensor and a 60 second timer between training
the remaining sensors. If any of these timers expire,
the EVIC will abort the training procedure.
NOTE: If at any time the EVIC display reads(TRAIN-
ING ABORTED(, move the vehicle ahead at least
one foot and repeat the entire retraining procedure.
(4) Press MENU button to start retraining. Dis-
play will read9TRAIN LEFT FRONT TIRE9
NOTE: The order for retraining all four sensors is:
²Left Front
²Right Front
²Right Rear
²Left Rear
(5) Starting at left front tire, place Re-learn Mag-
net over valve stem (Fig. 17). Within approximately 5
seconds, vehicle horn will chirp indicating training
complete at that particular sensor. Remove the mag-
net.
(6) Repeat step (5) on remaining sensors as indi-
cated by EVIC until all four TPM sensors positions
are trained.
(7) Once EVIC displays9TRAINING COMPLETE9,
pressing either STEP, C/T, RESET or MENU button
will exit training routine.
REMOVAL
(1) Remove tire and wheel assembly from vehicle.
(Refer to 22 - TIRES/WHEELS - REMOVAL)
CAUTION: The cap used on this valve stem con-
tains an O-ring seal to prevent contamination and
moisture from entering the valve stem. Retain this
valve stem cap for reuse. Do not substitute a regu-
lar valve stem cap in its place.
CAUTION: The valve stem used on this vehicle is
made of aluminum and the core is nickel plated
brass. The original valve stem core must be rein-
stalled and not substituted with a valve stem core
made of a different material. This is required to pre-
vent corrosion in the valve stem caused by the dif-
ferent metals.
(2) Dismount tire from wheel following tire
changer manufacturers instructions while paying
special attention to the following to avoid damaging
the pressure sensor:
(a) When breaking the tire bead loose from the
wheel rim, avoid using the Bead Breaker in the
area of the sensor. That includes both front and
rear beads of the tire.
(b) When preparing to dismount the tire from
the wheel, carefully insert the mounting/dimount-
ing tool at the valve stem   10É (Fig. 18), then pro-
ceed to dismount the tire from the wheel. Use this
process on both the upper and lower tire beads.
(3) Using a thin wall socket, remove special nut
retaining sensor to wheel (Fig. 19).
(4) Remove sensor from wheel (Fig. 19).
Fig. 17 Magnet Placement Over Valve Stem
1 - RE-LEARN MAGNET
2 - VALVE STEM
RSTIRES/WHEELS22-11
SENSOR - TPM (Continued)
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