2003 CHRYSLER CARAVAN steering

that chamber to receive and load a new disc in that
chamber.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove screws holding CD changer.
(3) Disconnect the wire connector from the back of
the CD changer.
(4) Remove the CD changer from the vehicle (Fig.
6).
INSTALLATION
(1) Reconnect the wire connector to the CD
changer.
(2) Insert the CD changer into the instrument
panel.
NOTE: Use care when inserting CD changer so that
cable is not pinched or trapped against instrument
panel.
(3) Install screws holding CD changer.
(4) Reconnect the battery negative cable.
DVD PLAYER
DESCRIPTION
The DVD player (if equipped) is located in the
instrument panel below the radio. The DVD player
can hold one DVD at a time. Three RCA jacks on the
front of the unit allow the use of MP3 players, video
game systems or camcorders.
OPERATION
Operating instructions for the factory installed
DVD player can be found in the owner's manual pro-
vided with this vehicle.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove screws holding DVD player (Fig. 7).
(3) Disconnect the wire connector from the back of
the DVD player.
(4) Remove the DVD player from the vehicle.
INSTALLATION
(1) Connect the wire harness connector to the DVD
player.
(2) Insert the DVD player into the instrument
panel.
(3) Install mounting screws.
(4) Connect the battery negative cable.
INSTRUMENT PANEL
ANTENNA CABLE
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Fig. 6 CD - CHANGER
1 - CD-CHANGER
2 - POWER OUTLET
Fig. 7 DVD PLAYER
1 - DVD PLAYER
2 - POWER OUTLET
8A - 8 AUDIORS
CD CHANGER (Continued)
ProCarManuals.com

grid can be repaired using a Mopar Rear Window
Defogger Repair Kit (Part Number 4267922) or
equivalent. (Refer to 8 - ELECTRICAL/HEATED
GLASS/WINDSHIELD GRID - STANDARD PROCE-
DURE).
RADIO
DESCRIPTION
Available factory-installed radio receivers for this
model include:
²AM/FM/cassette/CD (RAZ sales code)
²AM/FM/CD with CD changer control (RBK sales
code)
²AM/FM/cassette with CD changer control fea-
ture (RBB sales code)
²AM/FM/cassette/CD with rear audio (RBU sales
code)
All factory-installed radio receivers can communi-
cate on the Programmable Communications Interface
(PCI) data bus network. All factory-installed receiv-
ers are stereo Electronically Tuned Radios (ETR) and
include an electronic digital clock function.
These radio receivers can only be serviced by an
authorized radio repair station. See the latest War-
ranty Policies and Procedures manual for a current
listing of authorized radio repair stations.
OPERATION
The radio receiver operates on ignition switched
battery current that is available only when the igni-
tion switch is in the On or Accessory/Accessory Delay
positions. The electronic digital clock function of the
radio operates on fused battery current supplied
through the IOD fuse, regardless of the ignition
switch position.
For more information on the features, setting pro-
cedures, and control functions for each of the avail-
able factory-installed radio receivers, refer to the
owner's manual. For complete circuit diagrams, refer
to the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, details of wire har-
ness routing and retention, connector pin-out infor-
mation and location views for the various wire
harness connectors, splices and grounds.
DIAGNOSIS AND TESTING - RADIO
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULDRESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Any diagnosis of the Audio system should
begin with the use of the DRB IIItdiagnostic
tool. For information on the use of the DRB
IIIt, refer to the appropriate Diagnostic Service
Manual.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
If the vehicle is equipped with remote radio
switches located on the back of the steering wheel
spokes, and the problem being diagnosed is related to
one of the symptoms listed below, be certain to check
the remote radio switches and circuits as described
in this group, prior to attempting radio diagnosis or
repair.
²Stations changing with no remote radio switch
input
²Radio memory presets not working properly
²Volume changes with no remote radio switch
input
²Remote radio switch buttons taking on other
functions
²CD player skipping tracks
²Remote radio switch inoperative.
CAUTION: The speaker output of the radio is a
ªfloating groundº system. Do not allow any speaker
lead to short to ground, as damage to the radio
may result.
(1) Check the fuse(s) in the junction block and the
Integrated Power Module (IPM). If OK, go to Step 2.
If not OK, repair the shorted circuit or component as
required and replace the faulty fuse(s).
(2) Check for battery voltage at the fuse in the
(IPM). If OK, go to Step 3. If not OK, repair the open
circuit to the battery as required.
(3) Turn the ignition switch to the ON position.
Check for battery voltage at the fuse in the junction
block. If OK, go to Step 4. If not OK, repair the open
circuit to the ignition switch as required.
(4) Turn the ignition switch to the OFF position.
Remove the radio, but do not unplug the wire har-
ness connectors. Check for continuity between the
radio chassis and a good ground. There should be
continuity. If OK, go to Step 5. If not OK, repair the
open radio chassis ground circuit as required.
(5) Connect the battery negative cable. Turn the
ignition switch to the ON position. Check for battery
voltage at the fused ignition switch output circuit
cavity of the radio wire harness connector. If OK, go
8A - 10 AUDIORS
QUARTER GLASS INTEGRAL ANTENNA - EXPORT (Continued)
ProCarManuals.com

motors, and fuel pumps that have been found to be
potential sources of RFI or EMI.
OPERATION
There are two common strategies that can be used
to suppress Radio Frequency Interference (RFI) and
ElectroMagnetic Interference (EMI) radio noise. The
first suppression strategy involves preventing the
production of RFI and EMI electromagnetic signals
at their sources. The second suppression strategy
involves preventing the reception of RFI and EMI
electromagnetic signals by the audio system compo-
nents.
The use of braided ground straps in key locations
is part of the RFI and EMI prevention strategy.
These ground straps ensure adequate ground paths,
particularly for high current components such as
many of those found in the starting, charging, igni-
tion, engine control and transmission control sys-
tems. An insufficient ground path for any of these
high current components may result in radio noise
caused by induced voltages created as the high cur-
rent seeks alternative ground paths through compo-
nents or circuits intended for use by, or in close
proximity to the audio system components or circuits.
Preventing the reception of RFI and EMI is accom-
plished by ensuring that the audio system compo-
nents are correctly installed in the vehicle. Loose,
corroded or improperly soldered wire harness connec-
tions, improperly routed wiring and inadequate audio
system component grounding can all contribute to
the reception of RFI and EMI. A properly grounded
antenna body and radio chassis, as well as a shielded
antenna coaxial cable with clean and tight connec-
tions will each help reduce the potential for reception
of RFI and EMI.
REMOTE SWITCHES
DESCRIPTION
A remote radio control switch option is available on
some models. Two rocker-type switches are mounted
on the back (instrument panel side) of the steering
wheel spokes (Fig. 12). The switch on the left spoke
is the seek switch and has seek up, seek down, and
preset station advance functions. The switch on the
right spoke is the volume control switch and has vol-
ume up, and volume down functions. The switch on
the right spoke also includes a ªmodeº control that
allows the driver to sequentially select AM radio, FM
radio, cassette player, CD player or CD changer (if
equipped).
OPERATION
These switches are resistor multiplexed units that
are hard-wired to the Body Control Module (BCM)
through the clockspring. The BCM sends the proper
messages on the Programmable Communications
Interface (PCI) data bus network to the radio
receiver. For diagnosis of the BCM or the PCI data
bus, the use of a DRB IIItscan tool and the proper
Diagnostic Procedures manual are recommended. For
more information on the operation of the remote
radio switch controls, refer to the owner's manual in
the vehicle glove box.
DIAGNOSIS AND TESTING - REMOTE
SWITCHES
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
Any diagnosis of the Audio system should
begin with the use of the DRB IIItdiagnostic
tool. For information on the use of the DRB
IIIt, refer to the appropriate Diagnostic Service
Manual.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
Fig. 12 Remote Radio Switch Operational View
1 - PRESET SEEK
2 - SEEK UP
3 - VOLUME UP
4 - MODE
5 - VOLUME DOWN
6 - SEEK DOWN
8A - 12 AUDIORS
RADIO NOISE SUPPRESSION COMPONENTS (Continued)
ProCarManuals.com

harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the airbag system capac-
itor to discharge before further service.
(2) Remove the remote radio switch(es) from the
steering wheel (Fig. 13). (Refer to 8 - ELECTRICAL/
AUDIO/REMOTE SWITCHES - REMOVAL).
(3) Use an ohmmeter to check the switch resis-
tance as shown in the Remote Radio Switch Test
table.
REMOTE RADIO SWITCH TEST
Switch Switch Position Resistance
Right
(White)Volume Up 1.210 Kilohms
Right
(White)Volume Down 3.010 Kilohms
Right
(White)Mode Advance 0.0511 Kilohms
Left
(Black)Seek Up 0.261 Kilohms
Left
(Black)Seek Down 0.681 Kilohms
Left
(Black)Pre-Set Station
Advance0.162 Kilohms
NOTE: The right remote radio switch back is white
in color. The left switch back is black in color. The
right/left remote radio switch orientation is with the
steering wheel installed, and driver in drivers seat.(4) If the switch resistance checks OK, go to Step
5. If not OK, replace the faulty switch.
(5) Check for continuity between the ground cir-
cuit cavity of the switch wire harness connector and
a good ground. There should be continuity. If OK, go
to Step 6. If not OK, repair the open circuit as
required.
(6) Unplug the 24-way white wire harness connec-
tor from the Body Control Module (BCM). Check for
continuity between the radio control circuit cavity of
the remote radio switch wire harness connector and a
good ground. There should be no continuity. If OK, go
to Step 7. If not OK, repair the short circuit as
required.
(7) Check for continuity between the radio control
circuit cavities of the remote radio switch wire har-
ness connector and the BCM wire harness connector.
There should be continuity. If OK, refer to the proper
Diagnostic Procedures manual to test the BCM and
the PCI data bus. If not OK, repair the open circuit
as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable. Wait two minutes for the airbag system capac-
itor to discharge before further service.
(2) Remove the driver side airbag module from the
vehicle. Refer to ELECTRICAL/RESTRAINTS/
DRIVER AIR BAG.
(3) Remove the steering wheel from the steering
column. Refer to STEERING/COLUMN/STEERING
WHEEL.
(4) Unplug the wire harness connector from the
remote radio switch (s).
(5) Remove three screws securing steering wheel
rear cover.
(6) Remove the remote radio switch from the steer-
ing wheel by depressing tabs on each side of each
switch.
NOTE: The right remote radio switch back is white
in color. The left switch back is black in color. The
right/left remote radio switch orientation is with the
steering wheel installed, and driver in drivers seat.
Fig. 13 REMOTE RADIO SWITCHES
1 - BLACK (LEFT) SWITCH
2 - WHITE (RIGHT) SWITCH
RSAUDIO8A-13
REMOTE SWITCHES (Continued)
ProCarManuals.com

INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Install remote radio switch to the steering
wheel.
(2) Install three screws securing steering wheel
rear cover.
(3) Connect the wire harness to the remote radio
switch.
(4) Install the steering wheel. Refer to STEERING/
COLUMN/STEERING WHEEL.
(5) Install the driver side airbag module. Refer to
ELECTRICAL/RESTRAINTS/DRIVER AIRBAG.
(6) Connect the battery negative cable.
SPEAKER
DIAGNOSIS AND TESTING - SPEAKER
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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.
Any diagnosis of the Audio system should
begin with the use of the DRB IIItdiagnostic
tool. For information on the use of the DRB
IIIt, refer to the appropriate Diagnostic Service
Manual.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
CAUTION: The speaker output of the radio is a
ªfloating groundº system. Do not allow any speakerlead to short to ground, as damage to the radio
may result.
(1) If all speakers are inoperative, check the radio
fuses in the junction block. If OK, go to Step 2. If not
OK, repair the shorted circuit or component as
required and replace the faulty fuse.
(2) Turn the ignition switch to the ON position.
Turn the radio receiver ON. Adjust the balance and
fader control controls to check the performance of
each individual speaker. Note the speaker locations
that are not performing correctly. Go to Step 3.
(3) Turn the radio receiver OFF. Turn the ignition
OFF. Disconnect and isolate the battery negative
cable. Remove the radio receiver.
(4) Check both the speaker feed (+) circuit and
return (-) circuit cavities for the inoperative speaker
at the radio receiver wire harness connector for con-
tinuity to ground. There should be no continuity. If
OK, go to Step 5. If not OK, repair the shorted
speaker feed (+) and/or return (-) circuits(s) to the
speaker as required.
(5) Disconnect wire harness connector at the inop-
erative speaker. Check for continuity between the
speaker feed (+) circuit cavities of the radio receiver
wire harness connector and the speaker wire harness
connector. Repeat the check between the speaker
return (-) circuit cavities of the radio receiver wire
harness connector and the speaker wire harness con-
nector. In each case, there should be continuity. If
OK, replace the faulty speaker. If not OK, repair the
open speaker feed (+) and/or return (-) circuits(s) as
required.
REMOVAL
D-PILLAR SPEAKER
(1) Disconnect and isolate the battery negative
cable.
(2) Remove rear header trim (right side speaker).
(3) Remove jack cover (left side speaker).
(4) Remove liftgate scuff plate.
(5) Remove upper seat belt bolt. (Refer to 8 -
ELECTRICAL/RESTRAINTS/SEAT BELT OUT-
BOARD FRONT - REMOVAL).
(6) Partially remove quarter trim panel to access
the D-pillar speaker.
(7) Slide the speaker from the retainer (Fig. 14).
(8) Disconnect the wire harness connector from the
speaker.
FRONT DOOR SPEAKER
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the front door trim panel. (Refer to 23
- BODY/DOOR - FRONT/TRIM PANEL - REMOV-
AL).
8A - 14 AUDIORS
REMOTE SWITCHES (Continued)
ProCarManuals.com

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

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

OPERATION - SENSOR RETURN - PCM INPUT
The sensor return circuit provides a low electrical
noise ground reference for all of the systems sensors.
The sensor return circuit connects to internal ground
circuits within the Powertrain Control Module
(PCM).
OPERATION - DATA BUS COMMUNICATION
RECEIVE - PCM INPUT
The PCM uses the SCI communication bus to pre-
form engine diagnostics and flash operations. The
transmission side of the PCM uses the SCI commu-
nication bus to flash new software. However, diagnos-
tics is performed via the vehicles J1850 bus for the
transmission side of the PCM.
OPERATION - IGNITION SENSE - PCM INPUT
The ignition sense input informs the Powertrain
Control Module (PCM) that the ignition switch is in
the crank or run position.
OPERATION - PCM GROUND
Ground is provided through multiple pins of the
PCM connector. Depending on the vehicle there may
be as many as two different ground pins. There are
power grounds and sensor grounds.
The power grounds are used to control the ground
side relays, solenoids, ignition coil or injectors. The
signal ground is used for any input that uses sensor
return for ground, and the ground side of any inter-
nal processing component.
The PCM case is shielded to prevent RFI and EMI.
The PCM case is grounded and must be firmly
attached to a good, clean body ground.
Internally all grounds are connected together, how-
ever there is noise suppression on the sensor ground.
For EMI and RFI protection the housing and cover
are also grounded separately from the ground pins.
OPERATION
OPERATION - 8-VOLT SUPPLY - PCM OUTPUT
- SBEC CONTROLLER
The PCM supplies 8 volts to the crankshaft posi-
tion sensor, camshaft position sensor.
OPERATION - 5 VOLT SUPPLY - PCM OUTPUT
The PCM supplies 5 volts to the following sensors:
²A/C pressure transducer
²Ambient Temperature sensor
²Battery temperature
²Camshaft Position Sensor (NGC)
²Crankshaft Position Sensor (NGC)
²Electronic Throttle Control (1.6L)²Engine coolant temperature sensor
²Inlet Air Temperature Sensor
²Knock sensor
²Linear EGR solenoid (if equipped)
²Manifold absolute pressure sensor
²Oil Pressure Switch
²Pedal Position Sensor (1.6L)
²Throttle position sensor
²Vehicle Speed Sensor
STANDARD PROCEDURE
STANDARD PROCEDURE - OBTAINING
DIAGNOSTIC TROUBLE CODES
BULB CHECK
Key on: Bulb illuminated until vehicle starts, as
long as all once per trip (readiness) monitors com-
pleted. If monitors havenotbeen completed, then:
Key on: bulb check for about 5 to 8 seconds, lamp
then flashes if once per trip (readiness) monitors
havenotbeen completed until vehicle is started,
then MIL is extinguished.
OBTAINING DTC'S USING DRB SCAN TOOL
(1) Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located in
the passenger compartment; at the lower edge of
instrument panel; near the steering column.
(2) Turn the ignition switch on and access the
ªRead Faultº screen.
(3) Record all the DTC's and ªfreeze frameº infor-
mation shown on the DRB scan tool.
(4) To erase DTC's, use the ªErase Trouble Codeº
data screen on the DRB scan tool.Do not erase any
DTC's until problems have been investigated
and repairs have been performed.
STANDARD PROCEDURE - PINION FACTOR
SETTING
NOTE: This procedure must be performed if the
PCM/TCM has been replaced with a NEW or
replacement unit. Failure to perform this procedure
will result in an inoperative or improperly calibrated
speedometer.
The vehicle speed readings for the speedometer are
taken from the output speed sensor. The PCM/TCM
must be calibrated to the different combinations of
equipment (final drive and tires) available. Pinion
Factor allows the technician to set the Powertrain/
Transmission Control Module initial setting so that
the speedometer readings will be correct. To properly
RSELECTRONIC CONTROL MODULES8E-15
POWERTRAIN CONTROL MODULE (Continued)
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