sensor CHRYSLER CARAVAN 2003 Owner's Guide

CHIME/BUZZER
TABLE OF CONTENTS
page page
CHIME/BUZZER
DESCRIPTION..........................1
OPERATION............................1WARNING.............................1
DIAGNOSIS AND TESTING - CHIME SYSTEM . . 1
CHIME/BUZZER
DESCRIPTION
The chime/buzzer system provides the driver with
warning chimes for:
²Seat Belt
²Exterior Lamps ON
²Key-In Ignition
²Engine Temperature Critical
²Turn Signals ON
²Dome Lamp ON
²Low Oil Pressure
²High Speed Warning
²Warning Lamp Announcement
²Key-In Accessory
²Low/High Tire Pressure
²Service Tire Pressure Monitor (TPM)
HIGH SPEED WARNING - EXPORT
The chime will sound, acting as a warning to the
driver that the vehicle speed has exceeded 120   3
kph (75   2 mph).
Refer to the proper Body Diagnostic Procedures
manual for further description of chimes.
OPERATION
Refer to the proper Body Diagnostic Procedures
manual for complete chime/buzzer operation and con-
ditions for operation.
HIGH SPEED WARNING - EXPORT
When the vehicle speed sensor sees 120 3kph
(75   2 mph), it sends a PCI data bus message to the
Body Control Module (BCM). The BCM then turns on
the chime to let the driver know that the vehicle has
reached a speed greater than 120 3kph(75 2
mph). This audible message will continue until the
vehicle is slowed below the predetermined speed.
WARNING
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
DIAGNOSIS AND TESTING - CHIME SYSTEM
Refer to the proper Body Diagnostic Procedures
manual for complete Diagnosis and Testing of the
Chime System.
NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER'S SEAT BELT IS NOT BUCKLED.
(1) Using a DRB llltscan tool, actuate chime
(BCM actuates).
(2) Using a voltmeter, check for voltage:
(a) BCM has two battery feeds at pin 1 and pin
5 of the 6±way connector.
(b) Pin 5 of the (BX2) 32 way connector of the
BCM for ignition feed.
(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to
the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
RSCHIME/BUZZER8B-1
ProCarManuals.com

(3) Check drivers seat belt buckle switch input
(from Occupant Restraint Controller (ORC) for a
closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.
(4) Verify Programmable Communication Interface
(PCI) data bus communication between ORC and
BCM.
NO FASTEN SEAT BELT LAMP WHEN IGNITION
SWITCH IS TURNED ON.
(1) Check for burned out lamp.
(2) Using a voltmeter check for voltage at the clus-
ter connector:
(a) Pin 2 of the mechanical instrument cluster
for battery feed.
(b) Pin 11 of the mechanical instrument cluster
for ignition voltage.
(3) Repair as necessary.
FASTEN SEAT BELT LAMP OR TONE CONTINUES
FOR MORE THAN 10 SECONDS AFTER SEAT
BELTS ARE FASTENED AND DRIVER'S DOOR IS
CLOSED.
Refer to the proper Body Diagnostic Procedures
manual.
NO TONE WHEN PARK OR HEADLAMPS ARE ON
AND DRIVER'S DOOR IS OPEN.
Make sure ignition is in lock position with the key
removed.
(1) Check the BCM DTC's and BCM sensors to
verify the door is open. Repair as necessary.
(2) Actuate Chime (BCM actuates).
(3) Inspect BCM connectors and wires for proper
connection.
(4) Measure with a voltmeter the voltage (12v) on
BCM connector (PX2) pin 34 with harness connected.
(5) Check BCM sensors to verify headlamp switch
position.
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)
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ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
ELECTRONIC CONTROL MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING.......................2
BODY CONTROL MODULE
DESCRIPTION..........................3
OPERATION............................3
REMOVAL.............................4
INSTALLATION..........................5
CONTROLLER ANTILOCK BRAKE
DESCRIPTION..........................5
OPERATION............................5
REMOVAL.............................6
INSTALLATION..........................6
DATA LINK CONNECTOR
DESCRIPTION..........................6
OPERATION............................7
FRONT CONTROL MODULE
DESCRIPTION..........................7
OPERATION............................7
DIAGNOSIS AND TESTING - FRONT
CONTROL MODULE....................7
REMOVAL.............................8
INSTALLATION..........................8
HEATED SEAT MODULE
DESCRIPTION..........................8
OPERATION............................9
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE.............................9
REMOVAL.............................9
INSTALLATION.........................10
MEMORY SEAT/MIRROR MODULE
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING - MEMORY
SEAT/MIRROR MODULE................10
REMOVAL.............................10
INSTALLATION.........................10
POWER LIFTGATE CONTROL MODULE
DESCRIPTION.........................10
OPERATION...........................11
REMOVAL.............................11
INSTALLATION.........................11
POWERTRAIN CONTROL MODULE
DESCRIPTION
DESCRIPTION........................11OPERATION - SENSOR RETURN - PCM
INPUT..............................15
OPERATION - DATA BUS COMMUNICATION
RECEIVE - PCM INPUT.................15
OPERATION - IGNITION SENSE - PCM
INPUT..............................15
OPERATION - PCM GROUND............15
OPERATION
OPERATION - 8-VOLT SUPPLY - PCM
OUTPUT - SBEC CONTROLLER..........15
OPERATION - 5 VOLT SUPPLY - PCM
OUTPUT............................15
STANDARD PROCEDURE
STANDARD PROCEDURE - OBTAINING
DIAGNOSTIC TROUBLE CODES..........15
STANDARD PROCEDURE - PINION
FACTOR SETTING.....................15
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE........................16
REMOVAL
REMOVAL - SBEC CONTROLLER.........16
REMOVAL - NGC CONTROLLER..........17
INSTALLATION
INSTALLATION - SBEC CONTROLLER.....17
INSTALLATION.......................17
SENTRY KEY IMMOBILIZER MODULE
DESCRIPTION.........................18
OPERATION...........................18
REMOVAL.............................18
INSTALLATION.........................19
SLIDING DOOR CONTROL MODULE
DESCRIPTION.........................19
OPERATION...........................19
REMOVAL.............................19
INSTALLATION.........................20
TRANSMISSION CONTROL MODULE
DESCRIPTION.........................20
OPERATION...........................20
STANDARD PROCEDURE
STANDARD PROCEDURE - PINION
FACTOR SETTING.....................23
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE........................23
REMOVAL.............................23
INSTALLATION.........................24
RSELECTRONIC CONTROL MODULES8E-1
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(5) Obtain ignition keys to be programmed from
customer (8 keys maximum).
(6) Using the DRB III, erase all ignition keys by
selecting MISCELLANEOUS and ERASE ALL CUR-
RENT IGN. KEYS.
(7) Program all ignition keys.
Learned Key In Ignition - Ignition key transponder
ID is currently programmed in SKIM memory.
BODY CONTROL MODULE
DESCRIPTION
The Body Control Module (BCM) is located in the
passenger compartment, attached to the bulkhead
underneath the left side of the instrument panel.
The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus.
OPERATION
The Body Control Module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the BCM is interfaced to the
vehicle's serial bus communications network, referred
to as the Programmable Communications Interface
(PCI) bus.
This network consists of the;
²Powertrain Control Module (PCM)
²Transmission Control Module (TCM)
²Mechanical Instrument Cluster (MIC)
²Occupant Restraint Controller (ORC)
²Compass/Mini-Trip Computer (CMTC)
²Electronic Vehicle Information Center (EVIC)
²Controller Antilock Brake (CAB)²HVAC Control Module
²Sliding Door Control Modules (driver and pas-
senger side doors)
²Power Liftgate Module (PLG)
²Audio system equipped with RAZ, RBU, RBK,
and RBB radios.
²Side Impact Airbag Control Module (SIACM)
²Memory Seat Module (MSM)
²Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is
supplied to the module.
The BCM provides the following features:
²Power Door Locks
²Automatic Door Locks
²Battery Protection - The BCM will automatically
turn off all exterior lamps after 3 minutes, and all
interior lamps after 15 minutes after the ignition is
turned off, if they are not turned off by the driver.
²Chime Control
²Compass/Mini-Trip support.
²Interior Lighting (Courtesy/Reading Lamps)
²BCM Diagnostic Reporting
²Electronic Liftgate Release (with Power Door
Locks)
²Exterior Lighting
²Headlamp Time Delay (with/without Automatic
Headlamps)
²Illuminated Entry
²Fade to Off Interior Lamps - This feature dims
the interior lighting (courtesy lamps) gradually if the
BCM does not receive any new inputs that would
cause the interior lamps to remain on.
²Pulse Width Modulated Instrument Panel Dim-
ming
²Door Lock Inhibit - This feature disables the
door lock functions if the key is in the ignition and
either front door is ajar. Pressing the Remote Keyless
Entry (RKE) lock/unlock button under these condi-
tions result in normal lock/unlock activation.
The BCM has the ability to LEARN additional fea-
tures in the vehicle, provided the appropriate switch
input and PCI data bus messages are received. Refer
to the LEARNED FEATURES table.
RSELECTRONIC CONTROL MODULES8E-3
ELECTRONIC CONTROL MODULES (Continued)
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(6) Remove the screws holding the BCM to the
bulkhead.
(7) Remove the BCM from the mounting bracket.
INSTALLATION
(1) Install the BCM to the mounting bracket.
(2) Install the screws holding the BCM to the
bulkhead.
(3) Connect the five wire connectors to the bottom
of the Body Control Module (BCM).
(4) Install the knee blocker and reinforcement
(Refer to 23 - BODY/INSTRUMENT PANEL/KNEE
BLOCKER REINFORCEMENT - INSTALLATION).
(5) Install the lower instrument panel silencer.
(6) Connect the battery negative cable.
(7) Verify proper operation of BCM and its func-
tions.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The controller antilock brake (CAB) is a micropro-
cessor-based device which monitors the antilock
brake system (ABS) during normal braking and con-
trols it when the vehicle is in an ABS stop. The CAB
is mounted to the HCU as part of the integrated con-
trol unit (ICU) (Fig. 1). The CAB uses a 24-way elec-
trical connector on the vehicle wiring harness. The
power source for the CAB is through the ignition
switch in the RUN or ON position. The CAB is on
the PCI bus.
OPERATION
The primary functions of the controller antilock
brake (CAB) are to:
²Monitor the antilock brake system for proper
operation.
²Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
²Control fluid modulation to the wheel brakes
while the system is in an ABS mode.
²Store diagnostic information.
²Provide communication to the DRBIIItscan tool
while in diagnostic mode.
²Illuminate the amber ABS warning indicator
lamp.
²(With traction control only) Illuminate the TRAC
ON lamp in the message center on the instrument
panel when a traction control event occurs.
²(with traction control only) Illuminate the TRAC
OFF lamp when the amber ABS warning indicator
lamp illuminates.
The CAB constantly monitors the antilock brake
system for proper operation. If the CAB detects a
fault, it will turn on the amber ABS warning indica-
tor lamp and disable the antilock braking system.
The normal base braking system will remain opera-
tional.
NOTE: If the vehicle is equipped with traction con-
trol, the TRAC OFF lamp will illuminate anytime the
amber ABS warning indicator lamp illuminates.
The CAB continuously monitors the speed of each
wheel through the signals generated by the wheel
speed sensors to determine if any wheel is beginning
to lock. When a wheel locking tendency is detected,
the CAB commands the CAB command coils to actu-
ate. The coils then open and close the valves in the
HCU that modulate brake fluid pressure in some or
all of the hydraulic circuits. The CAB continues to
control pressure in individual hydraulic circuits until
a locking tendency is no longer present.
The CAB contains a self-diagnostic program that
monitors the antilock brake system for system faults.
When a fault is detected, the amber ABS warning
indicator lamp is turned on and the fault diagnostic
trouble code (DTC) is then stored in a diagnostic pro-
gram memory. A latched fault will disable certain
system functionality for the current ignition cycle. An
unlatched fault will disable certain system function-
ality until the fault condition disappears. These
DTC's will remain in the CAB memory even after the
ignition has been turned off. The DTC's can be read
and cleared from the CAB memory by a technician
using the DRBIIItscan tool. If not cleared with a
DRBIIItscan tool, the fault occurrence and DTC will
Fig. 1 Integrated Control Unit (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
RSELECTRONIC CONTROL MODULES8E-5
BODY CONTROL MODULE (Continued)
ProCarManuals.com

be automatically cleared from the CAB memory after
the identical fault has not been seen during the next
3,500 miles. Drive-off may be required for the amber
ABS warning indicator lamp to go out on the next
ignition cycle.
CAB INPUTS
²Wheel speed sensors (four)
²Brake lamp switch
²Ignition switch
²System and pump voltage
²Ground
²Traction control switch (if equipped)
²Diagnostic communication (PCI)
CAB OUTPUTS
²Amber ABS warning indicator lamp actuation
(via BUS)
²Red BRAKE warning indicator lamp actuation
(via BUS)
²Instrument cluster (MIC) communication (PCI)
²Traction control lamps (if equipped)
²Diagnostic communication (PCI, via BUS)
REMOVAL
(1) Disconnect the battery cables.
(2) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(3) Disconnect the vacuum hose connector at the
tank built into the battery tray.
(4) Remove the screw securing the coolant filler
neck to the battery tray.
(5) Remove the battery tray (Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/TRAY - REMOVAL).
(6) Pull up on the CAB connector lock and discon-
nect the 24±way electrical connector (Fig. 2).
(7) Disconnect the pump/motor connector from the
CAB.
(8) Remove the screws securing the CAB to the
HCU (Fig. 3)
(9) Pull CAB straight forward off HCU.
INSTALLATION
(1) Slide the CAB onto the HCU (Fig. 3).
(2) Install screws securing the CAB to the HCU
(Fig. 3) Tighten the mounting screws to 2 N´m (17 in
lbs).
(3) Reconnect the 24±way wiring connector and
the pump/motor wiring connector. (Fig. 2)
(4) Install the battery tray (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - INSTALLATION).
(5) Install the screw securing the coolant filler
neck to the battery tray.
(6) Reconnect the vacuum hose to the coolant tank
built into the battery tray.(7) Install the battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(8) Reconnect the battery cables.
(9) Connect a DRBIIItto the vehicle. Check and
clear any faults, and initialize the system.
DATA LINK CONNECTOR
DESCRIPTION
The data link connector is located inside the vehi-
cle, below instrument panel next to the center col-
umn (Fig. 4).
Fig. 2 CAB Connector Lock
1 - CONNECTOR LOCK
2 - CAB
Fig. 3 CAB Mounting Screws
1 - HCU
2 - MOUNTING SCREWS
3 - CAB
8E - 6 ELECTRONIC CONTROL MODULESRS
CONTROLLER ANTILOCK BRAKE (Continued)
ProCarManuals.com

switch and the heated seat sensor to operate and
control the heated seat elements in the front seat.
The heated seat modules cannot be repaired. If
either of the heated seat modules are damaged or
faulty, the entire module must be replaced.
OPERATION
The heated seat module operates on fused battery
current received from the integrated power module.
The module is grounded at all times through the seat
wire harness. Inputs to the module include a resistor
multiplexed heated seat switch request circuit for the
heated seat switch and the heated seat sensor inputs
from the seat cushions of each front seat. In response
to those inputs the heated seat module controls bat-
tery current feeds to the heated seat elements.
When a heated seat switch request signal is
received by the heated seat module and the enable
input is high, the heated seat module energizes the
selected heated seat sensor circuit and the sensor
provides the module with an input indicating the
surface temperature of the selected seat cushion.
The Low heat set point is about 35É C (95É F), and
the High heat set point is about 40É C (104É F). If the
seat cushion surface temperature input is below the
temperature set point for the selected temperature
setting, the heated seat module energizes an N-chan-
nel Field Effect Transistor (N-FET) within the mod-
ule which energizes the heated seat elements in theselected seat cushion and back. When the sensor
input to the module indicates the correct tempera-
ture set point has been achieved, the module de-en-
ergizes the N-FET which de-energizes the heated
seat elements. The heated seat module will continue
to cycle the N-FET as needed to maintain the
selected temperature set point.
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE
If a heated seat heats but one or both indicator
lamps on the heated seat switch fail to operate, test
the heated seat switch. Refer toDiagnosis and
Testing Heated Seat Switchin Heated Seats for
heated seat switch diagnosis and testing procedures.
If the heated seat switch checks OK, proceed as fol-
lows.
(1) Check the heated seat element (Refer to 8 -
ELECTRICAL/HEATED SEATS/HEATED SEAT
ELEMENT - DIAGNOSIS AND TESTING).
(2) Check the heated seat sensor (Refer to 8 -
ELECTRICAL/HEATED SEATS/HEATED SEAT
SENSOR - DIAGNOSIS AND TESTING).
(3) Check the heated seat switch (Refer to 8 -
ELECTRICAL/HEATED SEATS/DRIVER HEATED
SEAT SWITCH - DIAGNOSIS AND TESTING).
NOTE: Refer to Wiring for the location of complete
heated seat system wiring diagrams and connector
pin-out information.
(4) Using a voltmeter, back probe the appropriate
heated seat module connector, do not disconnect.
Check for battery voltage at the appropriate pin cav-
ities. If OK go to Step 5. If not OK, repair the open
or shorted voltage supply circuit as required.
(5) Using a ohmmeter, back probe the appropriate
heated seat module connector, do not disconnect.
Check for proper continuity to ground on the ground
pin cavities. Continuity should be present. If OK
replace the heated seat module with a known good
unit and retest system, if Not OK, Repair the open or
shorted ground circuit as required.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the appropriate front seat from the
vehicle (Refer to 23 - BODY/SEATS/SEAT - REMOV-
AL).
(3) Unsnap the module from the seat cushion pan.
(4) Disconnect the module wire harness connec-
tors.
Fig. 7 HEATED SEAT MODULE
1 - HEATED SEAT MODULE
2 - C1 CONNECTOR
3 - C3 CONNECTOR
4 - C1 CONNECTOR
RSELECTRONIC CONTROL MODULES8E-9
HEATED SEAT MODULE (Continued)
ProCarManuals.com

OPERATION
The PLG control module contains the electronic cir-
cuitry and software used to control the sequence of
events for the PLG system. This module comunicates
on the PCI bus circuit with the vehicles body control
module to monitor many different inputs and outputs
such as door lock status, transmission gear selector
position and vehicle speed. Refer to PLG system
operation for more information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove left D-pillar trim panel from the vehi-
cle. Refer to Body for the procedure.
(3) Disconnect the wire harness connections from
the PLG motor assembly (Fig. 8).
(4) Remove the screw holding the PLG control
module to the D-pillar (Fig. 8).
(5) Remove the PLG control module from the vehi-
cle.
INSTALLATION
(1) Install the PLG control module on the D-pillar
and install retaining screw. Torque the screw to 14.5
in. lbs.(2) Connect the wire harness connections on the
PLG control module. Be certain to slide connector
locks to the locked position.
(3) Install the D-pillar trim panel on the vehicle.
Refer to the Body section for the procedure.
(4) Connect the negative battery cable.
(5) Using an appropriate scan tool, check any
erase any PLG control module diagnostic trouble
codes.
(6) Verify PLG system operation. Cycle the PLG
through one complete open and close cycle, this will
allow the PLG control module to relearn its cycle
with the new components.
POWERTRAIN CONTROL
MODULE
DESCRIPTION
DESCRIPTION
The Powertrain Control Module (PCM) is a digital
computer containing a microprocessor (Fig. 9). The
PCM receives input signals from various switches
and sensors referred to as Powertrain Control Mod-
ule Inputs. Based on these inputs, the PCM adjusts
various engine and vehicle operations through
devices referred to as Powertrain Control Module
Outputs.Fig. 8 POWER LIFTGATE CONTROL MODULE
1 - POWER LIFTGATE CONTROL MODULE
2 - RETAINING SCREWS
3 - D-PILLAR
4 - POWER LIFTGATE MOTOR
5 - ELECTRICAL CONNECTORS
Fig. 9 Powertrain Control Module (PCM)
1 - Battery
2 - Power Distribution Center
3 - Powertrain Control Module
RSELECTRONIC CONTROL MODULES8E-11
POWER LIFTGATE CONTROL MODULE (Continued)
ProCarManuals.com

NOTE: PCM Inputs:
²Air Conditioning Pressure Transducer
²Ambient temperature Sensor
²ASD Relay
²Battery Temperature Sensor (NGC)
²Battery Voltage
²Brake Switch
²Camshaft Position Sensor
²Crankshaft Position Sensor
²Distance Sensor (from transmission control mod-
ule)
²EGR Position Feedback
²Engine Coolant Temperature Sensor
²Heated Oxygen Sensors
²Ignition sense
²Intake Air Temperature Sensor
²Knock Sensor
²Leak Detection Pump Feedback
²Manifold Absolute Pressure (MAP) Sensor
²Park/Neutral
²PCI Bus
²Power Steering Pressure Switch
²Proportional Purge Sense
²SCI Receive
²Speed Control
²Throttle Position Sensor
²Torque Management Input
²Transaxle Control Module (3.3/3.8L Only)
²Transmission Control Relay (Switched B+) (2.4L
Only)
²Transmission Pressure Switches (2.4L Only)
²Transmission Temperature Sensor (2.4L Only)
²Transmission Input Shaft Speed Sensor (2.4L
Only)
²Transmission Output Shaft Speed Sensor (2.4L
Only)
²Transaxle Gear Engagement
²Vehicle Speed
NOTE: PCM Outputs:
²Air Conditioning Clutch Relay
²Automatic Shut Down (ASD) and Fuel Pump
Relays
²Data Link Connector (PCI and SCI Transmit)
²Double Start Override
²EGR Solenoid
²Fuel Injectors
²Generator Field
²High Speed Fan Relay
²Idle Air Control Motor
²Ignition Coils
²Leak Detection Pump
²Low Speed Fan Relay
²MTV Actuator
²Proportional Purge Solenoid²SRV Valve
²Speed Control Relay
²Speed Control Vent Relay
²Speed Control Vacuum Relay
²8 Volt Output
²5 Volt Output
²Torque Reduction Request
²Transmission Control Relay (2.4L Only)
²Transmission Solenoids (2.4L Only)
²Vehicle Speed
Based on inputs it receives, the powertrain control
module (PCM) adjusts fuel injector pulse width, idle
speed, ignition timing, and canister purge operation.
The PCM regulates the cooling fans, air conditioning
and speed control systems. The PCM changes gener-
ator charge rate by adjusting the generator field.
The PCM adjusts injector pulse width (air-fuel
ratio) based on the following inputs.
²Battery Voltage
²Intake Air Temperature Sensor
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Exhaust Gas Oxygen Content (heated oxygen
sensors)
²Manifold Absolute Pressure
²Throttle Position
The PCM adjusts engine idle speed through the
idle air control motor based on the following inputs.
²Brake Switch
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Park/Neutral
²Transaxle Gear Engagement
²Throttle Position
²Vehicle Speed
The PCM adjusts ignition timing based on the fol-
lowing inputs.
²Intake Air Temperature
²Engine Coolant Temperature
²Engine Speed (crankshaft position sensor)
²Knock Sensor
²Manifold Absolute Pressure
²Park/Neutral
²Transaxle Gear Engagement
²Throttle Position
The automatic shut down (ASD) and fuel pump
relays are mounted externally, but turned on and off
by the powertrain control module through the same
circuit.
The camshaft and crankshaft signals are sent to
the powertrain control module. If the PCM does not
receive both signals within approximately one second
of engine cranking, it deactivates the ASD and fuel
pump relays. When these relays are deactivated,
power is shut off to the fuel injectors, ignition coils,
8E - 12 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)
ProCarManuals.com

fuel pump and the heating element in each oxygen
sensor.
The PCM contains a voltage converter that
changes battery voltage to a regulated 8.0 volts. The
8.0 volts power the camshaft position sensor, crank-
shaft position sensor and vehicle speed sensor. The
PCM also provides a 5.0 volts supply for the engine
coolant temperature sensor, intake air temperature
sensor, manifold absolute pressure sensor and throt-
tle position sensor.
The PCM engine control strategy prevents reduced
idle speeds until after the engine operates for 320 km
(200 miles). If the PCM is replaced after 320 km (200
miles) of usage, update the mileage in new PCM. Use
the DRBIIItscan tool to change the mileage in the
PCM. Refer to the appropriate Powertrain Diagnostic
Manual and the DRBIIItscan tool.
TRANSMISSION CONTROL (2.4L MODELS ONLY)
CLUTCH VOLUME INDEX (CVI)
An important function of the PCM is to monitor
Clutch Volume Index (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.
The PCM monitors gear ratio changes by monitor-
ing the Input and Output Speed Sensors. The Input,
or Turbine Speed Sensor sends an electrical signal to
the PCM that represents input shaft rpm. The Out-
put Speed Sensor provides the PCM with output
shaft speed information.
By comparing the two inputs, the PCM can deter-
mine transaxle gear ratio. This is important to the
CVI calculation because the PCM determines CVIs
by monitoring how long it takes for a gear change to
occur (Fig. 10).
Gear ratios can be determined by using the DRB
Scan Tool and reading the Input/Output Speed Sen-
sor values in the ªMonitorsº display. Gear ratio can
be obtained by dividing the Input Speed Sensor value
by the Output Speed Sensor value.
For example, if the input shaft is rotating at 1000
rpm and the output shaft is rotating at 500 rpm,
then the PCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changesto 1:1. The gear ratio changes as clutches are applied
and released. By monitoring the length of time it
takes for the gear ratio to change following a shift
request, the PCM can determine the volume of fluid
used to apply or release a friction element.
The volume of transmission fluid needed to apply
the friction elements are continuously updated for
adaptive controls. As friction material wears, the vol-
ume of fluid need to apply the element increases.
Certain mechanical problems within the clutch
assemblies (broken return springs, out of position
snap rings, excessive clutch pack clearance, improper
assembly, etc.) can cause inadequate or out-of-range
clutch volumes. Also, defective Input/Output Speed
Sensors and wiring can cause these conditions. The
following chart identifies the appropriate clutch vol-
umes and when they are monitored/updated:
CLUTCH VOLUMES
ClutchWhen Updated
Proper Clutch
Volume
Shift Sequence Oil Temperature Throttle Angle
L/R2-1 or 3-1 coast
downshift>70É <5É 35to83
2/4 1-2 shift
> 110É5 - 54É20 to 77
OD 2-3 shift 48 to 150
UD 4-3 or 4-2 shift > 5É 24 to 70
Fig. 10 Example of CVI Calculation
1 - OUTPUT SPEED SENSOR
2 - OUTPUT SHAFT
3 - CLUTCH PACK
4 - SEPARATOR PLATE
5 - FRICTION DISCS
6 - INPUT SHAFT
7 - INPUT SPEED SENSOR
8 - PISTON AND SEAL
RSELECTRONIC CONTROL MODULES8E-13
POWERTRAIN CONTROL MODULE (Continued)
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