2001 CHRYSLER VOYAGER CD changer

TABLE OF CONTENTS
1.0 INTRODUCTION.........................................................1
1.1SYSTEM COVERAGE...............................................1
1.2SIX-STEP TROUBLESHOOTING PROCEDURE..........................1
2.0 IDENTIFICATION OF SYSTEM.............................................1
3.0 SYSTEM DESCRIPTION AND FUNCTIONAL OPERATION......................1
3.1AIRBAG SYSTEM/OCCUPANT RESTRAINT CONTROLLER SYSTEM........2
3.1.1DRIVER AIRBAG...........................................3
3.1.2CLOCKSPRING............................................4
3.1.3PASSENGER AIRBAG......................................4
3.1.4SEAT BELT TENSIONER (SBT)...............................5
3.1.5SEAT BELT SWITCHES (SBS)................................5
3.1.6SIDE IMPACT AIRBAG CONTROL MODULE (SIACM)............5
3.1.7SEAT AIRBAGS (SAB)......................................6
3.1.8ORC/SIACM DIAGNOSTIC TROUBLE CODES..................6
3.1.9ACTIVE CODES...........................................7
3.1.10STORED CODES..........................................7
3.2AUDIO SYSTEM....................................................7
3.2.1REMOTE RADIO CONTROLS................................8
3.2.2CD CHANGER.............................................8
3.3BODY CONTROL MODULE...........................................8
3.4CHIME WARNING SYSTEM...........................................9
3.4.1CHIME PRIORITY..........................................9
3.4.2CHIME ON CONDITIONS....................................9
3.4.3WARNING LAMP ANNOUNCEMENT.........................10
3.4.4OTHER CHIME ON CONDITIONS............................10
3.5COMMUNICATION.................................................11
3.6DOOR AJAR SYSTEM..............................................12
3.7EXTERIOR LIGHTING SYSTEM......................................12
3.7.1HEADLAMP POWER......................................12
3.7.2HEADLAMP SWITCH......................................12
3.7.3PARK LAMP RELAY.......................................12
3.7.4FOG LAMP RELAY........................................12
3.7.5FOG LAMPS.............................................12
3.7.6EXTERIOR LIGHTING BATTERY SAVER......................13
3.7.7AUTO HEADLAMPS.......................................13
3.8FRONT CONTROL MODULE.........................................13
3.8.1CONTROLLED POWER FEEDS.............................13
3.8.2RELAY CONTROLS.......................................14
3.8.3ELECTRICAL INPUTS.....................................15
3.9HEATING & A/C...................................................16
3.9.1AUTOMATIC TEMPERATURE CONTROL (ATC)................16
3.9.1.1CABIN HEATER..........................................16
3.9.1.2SYSTEM OPERATION.....................................16
3.9.1.3BLOWER MOTOR OPERATION.............................16
3.9.1.4INFRARED SENSORS.....................................16
3.9.1.5REAR ATC SWITCH.......................................16
3.9.1.6COOLDOWN TESTING....................................16
3.9.1.7ACTIVE AND STORED TROUBLE CODES....................17
3.9.2MANUAL TEMPERATURE CONTROL.........................17
i

TABLE OF CONTENTS - Continued
3.9.2.1SYSTEM AVAILABILITY....................................17
3.9.2.2CABIN HEATER..........................................17
3.9.2.3ZONE CONTROL ± SINGLE-ZONE...........................17
3.9.2.4ZONE CONTROL ± DUAL-ZONE.............................17
3.9.2.5AIR DISTRIBUTION.......................................17
3.9.2.6DOOR ACTUATORS.......................................17
3.9.2.7DOOR ACTUATOR CONTROL..............................17
3.9.2.8HVAC SYSTEM RELAYS...................................18
3.9.2.9EVAPORATOR TEMPERATURE SENSOR.....................18
3.9.2.10A/C ± HEATER CONTROL MODULE, SWITCH OPERATION......18
3.9.2.11HVAC DIAGNOSTICS.....................................19
3.10CABIN HEATER...................................................19
3.10.1GENERAL SAFETY INFORMATION..........................19
3.10.2COMPONENT DESCRIPTION AND OPERATION...............19
3.10.2.1DCHA ASSEMBLY.........................................19
3.10.2.2COMBUSTION AIR FAN...................................20
3.10.2.3BURNER HOUSING.......................................20
3.10.2.4BURNER INSERT.........................................20
3.10.2.5CONTROL UNIT/HEAT EXCHANGER.........................20
3.10.2.6DOSING PUMP...........................................20
3.10.3OPERATION.............................................20
3.10.3.1ACTIVATION.............................................20
3.10.3.2HEATING................................................21
3.10.3.3DEACTIVATION...........................................21
3.10.4DIAGNOSTICS...........................................21
3.11INSTRUMENT CLUSTER............................................21
3.11.1INSTRUMENT CLUSTER SELF TEST........................22
3.11.2MESSAGE CENTER.......................................22
3.12INTERIOR LIGHTING...............................................22
3.12.1COURTESY LAMP CONTROL...............................22
3.12.2ILLUMINATED ENTRY.....................................22
3.12.3INTERIOR LIGHTING BATTERY SAVER......................22
3.13MEMORY SYSTEM.................................................22
3.13.1POWER SEAT............................................22
3.13.2MEMORY MIRRORS.......................................23
3.14OVERHEAD CONSOLE.............................................23
3.14.1COMPASS/MINI-TRIP COMPUTER (CMTC)....................23
3.14.2ELECTRONIC VEHICLE INFORMATION CENTER (EVIC)........23
3.14.3SETTING THE COMPASS..................................23
3.14.4SETTING THE VARIANCE..................................23
3.15POWER DOOR LOCK SYSTEM......................................24
3.15.1SLIDING DOOR MEMORY LOCK............................24
3.15.2DOOR LOCK INHIBIT......................................24
3.15.3AUTOMATIC DOOR LOCKS................................24
3.15.4REMOTE KEYLESS ENTRY (RKE)...........................24
3.16POWER FOLDING MIRRORS........................................24
3.17POWER LIFTGATE SYSTEM.........................................25
3.17.1POWER LIFTGATE........................................25
3.17.2DIAGNOSTIC FEATURES..................................25
3.17.3SYSTEM INHIBITORS.....................................25
3.18POWER SLIDING DOOR SYSTEM....................................25
3.18.1POWER SLIDING DOOR...................................25
3.18.2DIAGNOSTIC FEATURES..................................26
ii

TABLE OF CONTENTS - Continued
AUDIO
ALL OUTPUTS SHORTED...............................................189
AM SECTION.........................................................192
CASS ERROR.........................................................192
CASSETTE COMMUNICATION FAULT.....................................192
CASSETTE EJECT FAILURE.............................................192
CASSETTE LOADING FAILURE..........................................192
CASSETTE TAPE TENSION HIGH........................................192
CASSETTE TAPE TENSION LOW.........................................192
CD ERROR...........................................................192
CD MECHANICAL FAILURE.............................................192
FM SECTION..........................................................192
MICRO OUTPUT FAILURE..............................................192
RADIO ERROR........................................................192
*AM/FM SWITCH INOPERATIVE..........................................192
*ANY STATION PRESET SWITCH INOPERATIVE............................192
*BALANCE INOPERATIVE...............................................192
*CD EJECT SWITCH INOPERATIVE.......................................192
*EQUALIZER INOPERATIVE.............................................192
*FADER INOPERATIVE.................................................192
*FF/RW SWITCH INOPERATIVE..........................................192
*HOUR/MINUTE SWITCHES INOPERATIVE................................192
*PAUSE/PLAY SWITCH INOPERATIVE....................................192
*PWR SWITCH INOPERATIVE...........................................192
*SCAN SWITCH INOPERATIVE..........................................192
*SEEK SWITCH INOPERATIVE...........................................192
*SET SWITCH INOPERATIVE............................................192
*TAPE EJECT SWITCH INOPERATIVE.....................................192
*TIME SWITCH INOPERATIVE...........................................192
*TUNE SWITCH INOPERATIVE...........................................192
CD CHANGER MECHANICAL FAILURE....................................195
CD CHANGER PLAY FAILURE...........................................196
CD CHANGER READ FAILURE...........................................196
IMPROPER DISK IN CD CHANGER.......................................196
CD CHANGER POWER SUPPLY TOO HIGH................................197
CD CHANGER TEMPERATURE HIGH.....................................198
CD CHANGER TEMPERATURE LOW.....................................198
CD PLAY FAILURE.....................................................199
CD READ FAILURE....................................................199
IMPROPER DISK IN CD.................................................199
CD TEMPERATURE HIGH...............................................200
CD TEMPERATURE LOW...............................................200
FRONT OUTPUT SHORT................................................201
LEFT OUTPUT SHORT.................................................204
NBS OUTPUT 1 OPEN..................................................207
NBS OUTPUT 2 OPEN..................................................207
NBS OUTPUT 1 SHORT TO BATT........................................209
NBS OUTPUT 2 SHORT TO BATT........................................209
NO ANTENNA CONNECTION............................................211
NO VIN RECEIVED.....................................................212
VIN MISMATCH........................................................212
POWER SUPPLY TOO HIGH.............................................213
REAR OUTPUT SHORT.................................................214
vii

TABLE OF CONTENTS - Continued
B1823 WATER PUMP CIRCUIT: OPEN.....................................323
B1823 WATER PUMP CIRCUIT: SHORT TO GROUND........................323
B1824 FAN SWITCH LINE SHORT TO GROUND............................324
CABIN HEATER CONTROL CIRCUIT OPEN (ACTIVE)........................325
CABIN HEATER CONTROL CIRCUIT SHORT TO BATTERY (ACTIVE)...........329
*CABIN HEATER INOPERABLE FROM A/C - HEATER MODULE...............332
CHIME
*CHIME INOPERATIVE..................................................334
*KEY IN IGNITION AND DRIVER'S DOOR OPEN CHIME NOT OPERATING
PROPERLY...........................................................336
*PROBLEM WITH THE HIGH VEHICLE SPEED WARNING CHIME.............337
COMMUNICATION
ATC MESSAGES NOT RECEIVED........................................338
AUDIO MESSAGES NOT RECEIVED......................................339
BCM, PCI BUS SHORTED TO BATTERY...................................340
BCM, PCI BUS SHORTED TO GROUND...................................340
FCM, PCI BUS SHORTED TO BATTERY...................................340
FCM, PCI BUS SHORTED TO GROUND...................................340
COUNTRY CODE NOT PROGRAMMED...................................342
FCM MESSAGES NOT RECEIVED........................................343
FCM, BCM COMMUNICATION FAULT.....................................344
FCM, HVAC COMMUNICATION FAULT....................................345
FCM, PCI INTERNAL FAULT.............................................346
FCM, PCM COMMUNICATION FAULT.....................................347
FCM, RADIO COMMUNICATION FAULT...................................348
FCM, TCM COMMUNICATION FAULT.....................................349
IGNITION MUX SWITCH INPUT OPEN....................................350
IGNITION MUX SWITCH INPUT SHORT...................................352
IGNITION RUN OUTPUT SHORT.........................................353
INTERNAL BCM FAILURE...............................................357
LEFT PSD MESSAGES NOT RECEIVED...................................358
LIFTGATE MODULE MESSAGES NOT RECEIVED...........................359
MIC MESSAGES NOT RECEIVED........................................360
MSM MESSAGES NOT RECEIVED.......................................361
NO PCI MESSAGES FROM CD CHANGER.................................362
ORC MESSAGES NOT RECEIVED........................................364
OTIS MESSAGES NOT RECEIVED.......................................365
PCI INTERNAL HARDWARE FAILURE.....................................366
PCM MESSAGES NOT RECEIVED........................................367
RADIO MEM MSG NOT RECEIVED.......................................368
RIGHT PSD MESSAGES NOT RECEIVED..................................369
RUN/START HARDWIRE INPUT FAILURE..................................370
SKIM MESSAGES NOT RECEIVED.......................................371
TCM MESSAGES NOT RECEIVED........................................372
*BUS +/- SIGNALS OPEN FROM AUTOMATIC TEMPERATURE CONTROL
MODULE.............................................................373
*BUS +/- SIGNALS OPEN FROM MEMORY SEAT/MIRROR MODULE...........375
*BUS +/- SIGNALS OPEN FROM SENTRY KEY IMMOBILIZER MODULE........377
*BUS +/- SIGNALS OPEN OR NO RESPONSE FROM BODY CONTROL
MODULE.............................................................379
*BUS +/- SIGNALS OPEN OR NO RESPONSE FROM HVAC..................381
x

TABLE OF CONTENTS - Continued
C200 - GRAY (BODY SIDE).............................................1018
C200 - GRAY (INSTRUMENT PANEL SIDE)................................1020
C201 - YELLOW (BODY SIDE)..........................................1021
C201 - YELLOW (INSTRUMENT PANEL SIDE).............................1022
C202 - GRAY (COMPONENT SIDE)......................................1022
C202 - GRAY (INSTRUMENT PANEL SIDE)................................1023
C304 - YELLOW (BODY SIDE)..........................................1023
C304 - YELLOW (SEAT SIDE)...........................................1023
C305 - GRAY (BODY SIDE).............................................1024
C306 - YELLOW (BODY SIDE)..........................................1024
C306 - YELLOW (SEAT SIDE)...........................................1024
C307 - GRAY (BODY SIDE).............................................1024
C307 - GRAY (SEAT SIDE).............................................1025
C311 - GRAY (BODY SIDE).............................................1025
C311 - GRAY (REAR A/C JUMPER SIDE).................................1026
C314 (HIGH LINE) - BLACK (BODY SIDE).................................1026
C314 (HIGH LINE) - BLACK (LIFTGATE SIDE).............................1027
C315 (HIGH LINE) - BLACK (BODY SIDE).................................1027
C315 (HIGH LINE) - BLACK (LIFTGATE SIDE).............................1027
C316 (POWER SLIDING DOOR) - BLACK (LEFT DOOR WIRE TRACK ASSEMBLY
SIDE)...............................................................1028
C316 (POWER SLIDING DOOR) - BLACK (LEFT SLIDING DOOR SIDE)........1028
C317 (POWER SLIDING DOOR) - BLACK (RIGHT DOOR WIRE TRACK ASSEMBLY
SIDE)...............................................................1028
C317 (POWER SLIDING DOOR) - BLACK (RIGHT SLIDING DOOR SIDE)......1028
C322 (MEMORY) - BLACK (BODY SIDE)..................................1029
C322 (MEMORY) - BLACK (POWER SEAT SIDE)...........................1029
C324 (MANUAL SLIDING DOOR) - BLACK (LEFT DOOR WIRE TRACK ASSEMBLY
SIDE................................................................1029
C324 (MANUAL SLIDING DOOR) - BLACK (LEFT MANUAL SLIDING DOOR
SIDE)...............................................................1030
C325 (MANUAL SLIDING DOOR) - BLACK (RIGHT DOOR WIRE TRACK ASSEMBLY
SID.................................................................1030
C325 (MANUAL SLIDING DOOR) - BLACK (RIGHT MANUAL SLIDING DOOR
SIDE)...............................................................1030
C326 - YELLOW (SAFETY SEAT SIDE)...................................1030
C326 - YELLOW (SEAT SIDE)...........................................1030
C327 - YELLOW (SAFETY SEAT SIDE)...................................1031
C327 - YELLOW (SEAT SIDE)...........................................1031
C330 (DIESEL) - GRAY (CABIN HEATER JUMPER SIDE)....................1031
C330 (DIESEL) - LT. GRAY (BODY SIDE)..................................1031
C331 (DIESEL) - BLACK (CABIN HEATER JUMPER SIDE)...................1031
C331 (DIESEL) - GRAY (CABIN HEATED COMPONENT SIDE)................1032
CABIN HEATER ASSIST C1 (DIESEL) - BLACK 6 WAY......................1032
CABIN HEATER ASSIST C2 (DIESEL) - BLACK 2 WAY......................1032
CD CHANGER-8WAY................................................1033
CENTER DOME LAMP (BASE/HIGH LINE) - GRAY 3 WAY...................1033
CLOCKSPRING C1 - WHITE 6 WAY......................................1033
CLOCKSPRING C2 - YELLOW 4 WAY....................................1034
CLOCKSPRING C4 - BLACK 2 WAY......................................1034
CLOCKSPRING C5 - YELLOW 4 WAY....................................1034
CONTROLLER ANTILOCK BRAKE - BLACK 24 WAY........................1035
DATA LINK CONNECTOR - BLACK 16 WAY...............................1035
xx

TABLE OF CONTENTS - Continued
RIGHT SLIDING DOOR CONTROL MODULE C1 (POWER SLIDING DOOR) - BLACK
8 WAY ..............................................................1082
RIGHT SLIDING DOOR CONTROL MODULE C2 (POWER SLIDING DOOR) -
BLACK/RED 20 WAY..................................................1082
RIGHT SLIDING DOOR LATCH SENSING SWITCH (POWER SLIDING DOOR) -
BLACK 6 WAY........................................................1082
RIGHT SLIDING DOOR LOCK MOTOR (POWER SLIDING DOOR) - BLACK 4
WAY................................................................1083
RIGHT SLIDING DOOR LOCK MOTOR/AJAR SWITCH (MANUAL SLIDING DOOR) -
BLACK 4 WAY........................................................1083
RIGHT SLIDING DOOR MOTOR (POWER SLIDING DOOR) - BLACK 8 WAY. . . .1083
SENTRY KEY IMMOBILIZER MODULE - BLACK 6 WAY.....................1083
SIREN (UNITED KINGDOM) - BLACK 4 WAY..............................1083
THATCHAM ALARM MODULE C1 (UNITED KINGDOM) - BLACK 16 WAY.......1084
THATCHAM ALARM MODULE C2 (UNITED KINGDOM) - WHITE 4 WAY........1084
TRANSMISSION CONTROL MODULE (EATX) - BLACK 60 WAY..............1085
TXV SOLENOID (ATC)-2WAY.........................................1086
10.0 SCHEMATIC DIAGRAMS...............................................1087
10.1AIRBAG SYSTEM................................................1087
10.2AUDIO SYSTEM.................................................1088
10.2.1PREMIUM.............................................1088
10.2.2BASE.................................................1089
10.2.3CD CHANGER.........................................1090
10.2.4REMOTE RADIO CONTROLS.............................1091
10.3CABIN HEATER.................................................1092
10.4AUTOMATIC TEMPERATURE CONTROL SYSTEM....................1093
10.4.1FRONT ATC............................................1093
10.4.2REAR ATC.............................................1094
10.5COMMUNICATION...............................................1095
10.5.1PCM COMMUNICATION.................................1096
10.5.2ECM & CABIN HEATER ASSIST COMMUNICATION - DIESEL
ONLY.................................................1096
10.6DOOR AJAR WITH POWER SLIDING DOORS........................1097
10.7DOOR AJAR WITHOUT POWER SLIDING DOORS....................1098
10.8EXTERIOR LIGHTING............................................1099
10.9IGNITION SWITCH...............................................1100
10.10INSTRUMENT CLUSTER Ð BASE..................................1101
10.11INSTRUMENT CLUSTER & MESSAGE CENTER......................1102
10.12INTELLIGENT POWER MODULE/BODY CONTROL MODULE POWER AND
GROUNDS......................................................1103
10.13INTERIOR LIGHTING.............................................1104
10.14MANUAL TEMPERATURE CONTROLS..............................1105
10.14.1BASE MANUAL TEMPERATURE CONTROL SYSTEM LHD.....1105
10.14.2BASE MANUAL TEMPERATURE CONTROL SYSTEM RHD....1106
10.14.3DUAL-ZONE MANUAL TEMPERATURE CONTROL SYSTEM
LHD ..................................................1107
10.14.4DUAL-ZONE MANUAL TEMPERATURE CONTROL SYSTEM
RHD..................................................1108
10.14.5BLOWER MOTOR.......................................1109
10.15MEMORY SYSTEM...............................................1110
10.16OVERHEAD CONSOLE...........................................1111
xxiv

this type of system would only refer to this circuit.
A faulty speaker could not cause this DTC.
3.2.1 REMOTE RADIO CONTROLS
These radios can be controlled via remote radio
switches (optional). These switches are located on
the back side of the steering wheel. They control
mode, preset, seek up, seek down, volume up and
volume down functions.
These functions are inputs to the Body Control
Module and can be read with the DRBIIItunder
ªbody computerº. The switches are a multiplexed
signal to the BCM. The radio control MUX circuit is
a 5 volt line that is pulled to ground through
different value resistors built into the switches.
This causes a voltage drop to be seen by the BCM
and it sends a specific message to the radio on the
PCI Bus circuit. The radio then responses to the
message.
This circuit is fairly simple to troubleshoot. The
circuit must be complete from the switches in the
steering wheel to the BCM. The ground must be
complete so that the switches can cause the voltage
drop for the BCM to see. The circuit passes through
the clockspring so continuity through this devise
must be verified.
3.2.2 CD CHANGER
The new in-dash CD Changer is designed to fit
into the existing cubby bin in the center stack. This
new cartridge-less CD Changer is controlled by
your radio, and allows you to individually load up to
four discs at a time. However, due to its compact
design, the CD Changer can only carry out one
operation at a time. For example, you can not load
a new disc while playing another at the same time.
Each operation happens sequentially.
The radio unit installed with your system pro-
vides control over all features of the CD Changer
with the exception of the CD load and eject func-
tions, which are controlled by buttons located on the
front of the CD Changer. The radio also supplies the
power, ground, PCI Bus, left and right speaker
output thru a single DIN cable. All features you
would expect, such as Disc Up/Down, Track Up/
Down, Random and Scan are controlled by the
radio, which also displays all relevant CD Changer
information on the radio display.
The CD Changer contains a Load/Eject button
and an indicator light for each of the four disc
positions. The individual light indicates whether a
CD is currently loaded in that particular chamber of
the CD Changer. Pressing the individual Load/Eject
button for a particular chamber will eject a disc
currently present in that chamber. If the chamber iscurrently empty, actuating the Load/Eject button
will position that chamber to receive and load a new
disc in that chamber.
3.3 BODY CONTROL MODULE
The body control module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the module is interfaced to the
vehicle's serial bus communications network (PCI).
This network consists of the powertrain control
module (PCM), the engine control module (ECM) -
diesel only, the transmission control module (TCM),
the mechanical instrument cluster (MIC), the front
control module (FCM), the occupant restraint con-
troller (ORC), the compass/mini-trip (CMTC), the
electronic vehicle information center (EVIC), the
controller antilock brake (CAB), the HVAC control
module (ATC & MTC), the power sliding door (Left
& Right) modules (PSD), the power liftgate module
(PLG), the Audio system, the side impact airbag
control (left & right) modules (SIACM), the memory
seat/mirror module (MSMM), the RKE/thatcham
alarm module and the sentry key immobilizer mod-
ule (SKIM). The BCM is operational when battery
power is supplied to the module.
The body control module provides the following
features:
²Power Door Locks
²Automatic Door Lock
²Door Lock Inhibit
²Central Locking (with VTSS Only)
²Battery Protection
²The 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
²Compass/Minitrip Support
²Interior Lighting (Courtesy/Reading Lamps)
²BCM Diagnostic Reporting
²Electronic Liftgate Release (with Power Door
Locks)
²Exterior Lighting
²Power Folding Mirrors
²Remote Radio Controls
²Headlamp Time Delay (with/without Autohead-
lamps)
²Automatic Headlamps (with electrochromatic
mirror)
²Illuminated Entry
²Fade to Off
8
GENERAL INFORMATION

3.5 COMMUNICATION
The Programmable Communication Interface or
PCI Bus is a single wire multiplexed network capa-
ble of supporting binary encoded messages shared
between multiple modules. The PCI bus circuit is
identified as D25 and is white with a violet tracer.
Additional tracer colors may be added to the violet
in order to distinguish between different module
connections. The modules are wired in parallel.
Connections are made in the harness using splices.
One splice called the Diagnostic Junction Port,
serves as the ªHubº of the bus. The Diagnostic
Junction Port provides an access point to isolate
most of the modules on the bus in order to assist in
diagnosing the circuit. The following modules are
used on the RG:
²Body Control Module
²Front Control Module
²Occupant Restraint Controller
²Left Side Impact Airbag Control Module
²Right Side Impact Airbag Control Module
²Controller Antilock Brake
²Powertrain Control Module
²Engine Control Module - Diesel Only
²Radio
²CD Changer
²Transmission Control Module
²Automatic Temperature Control Module
²A/C Heater Control Module (MTC)
²Sentry Key Immobilizer Module
²RKE/Thatcham Alarm Module
²Memory Seat/Mirror Module
²Overhead Console
²Mechanical Instrument Cluster
²Left Sliding Door Control Module
²Right Sliding Door Control Module
²Power Liftgate Module
Each module provides its own bias and termina-
tion in order to transmit and receive messages. The
bus voltage is at zero volts when no modules are
transmitting and is pulled up to about seven and a
half volts when modules are transmitting.
The bus messages are transmitted at a rate
averaging 10800 bits per second. Since there is only
voltage present when the modules transmit and the
message length is only about 500 milliseconds, it is
ineffective to try and measure the bus activity witha conventional voltmeter. The preferred method is
to use the DRBIIItlab scope. The 12v square wave
selection on the 20-volt scale provides a good view of
the bus activity. Voltage on the bus should pulse
between zero and about seven and a half volts.
Refer to the following figure for some typical dis-
plays.
The PCI Bus failure modes are broken down into
two categories. Complete PCI Bus Communication
Failure and individual module no response. Causes
of complete PCI Bus Communication Failure in-
clude a short to ground or battery on the PCI
circuit. Individual module no response can be
caused by an open circuit at either the Diagnostic
Junction Port or the module, or an open battery or
ground circuit to the affected module.
Symptoms of a complete PCI Bus Communication
Failure would include but are not limited to:
²All gauges on the MIC stay at zero
²All telltales on MIC illuminate
²MIC backlighting at full intensity
²Dashed lines in the overhead console ambient
temperature display
²No response received from any module on the PCI
bus (except the PCM)
²No start (if equipped with Sentry Key Immobi-
lizer)
Symptoms of Individual module failure could
include any one or more of the above. The difference
would be that at least one or more modules would
respond to the DRBIIIt.
Diagnosis starts with symptom identification. If a
complete PCI Bus Communication Failure is sus-
pected, begin by identifying which modules the
vehicle is equipped with and then attempt to get a
response from the modules with the DRBIIIt.Ifany
modules are responding, the failure is not related to
the total bus, but can be caused by one or more
modules PCI circuit or power supply and ground
circuits. The DRBIIItmay display ªBUS +/- SIG-
NAL OPENº or ªNO RESPONSEº to indicate a
communication problem. These same messages will
be displayed if the vehicle is not equipped with that
particular module. The CCD error message is a
default message used by the DRBIIItand in no way
indicates whether or not the PCI bus is operational.
The message is only an indication that a module is
either not responding or the vehicle is not equipped.
11
GENERAL INFORMATION