
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
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

manual sliding door. When the child lock out switch
is on, the B pillar switches are disabled.
There is only one part number for the power
sliding door module (PSDM). The driver sliding
door harness has an additional ground circuit which
will identify it as the driver side. This eliminates
the need for a left and a right side module.
3.18.2 DIAGNOSTIC FEATURES
The PSDM can be flashed on vehicle via PCI bus
with a DRBIIItdiagnostic tool. The DRBIIItcan
read all inputs, actuate all outputs, read module
information, and read diagnostic trouble codes. As a
reminder, some DTC's can be set during normal
PSD operation.
3.18.3 SYSTEM INHIBITORS
1. Battery voltage too high or too low (above 16V,
below 9.5V)
2. Vehicle in gear
3. Vehicle speed > 0 mph/km/h
4. Child locks enabled inhibit the B pillar switch
operation
5. O/H console lockout will inhibit the B pillar
switches
6. Doors locked will inhibit all interior switches
from opening (Overhead Console, B Pillar). A
locked sliding door can be power closed.
3.19 REAR WINDOW DEFOG/HEATED
MIRROR/FRONT WIPER DE-ICE
The defroster button located on the HVAC control
controls the rear window defogger, heated side view
mirrors and front wiper de-icer grid. In addition the
front wiper de-ice function is turned on when front
defog/defrost mode is selected.
When the defroster button is pushed, the HVAC
control sends a bus message over the PCI bus to the
Front Control Module (FCM) which controls the
Rear Window Defogger relay. The defroster LED
will illuminate when the defroster function is on.
The defroster will function for 10 minutes or can be
cycled off sooner by pressing the defroster button
again. The front wiper de-icer grid receives its 12
volts from the accessory relay through fuse 11 and
the HVAC control module supplies the grid ground.
3.20 VEHICLE THEFT SECURITY SYSTEM
3.20.1 BASE ALARM SYSTEM
The Vehicle Theft Security System (VTSS) is part
of the Body Control Module (BCM). The BCM
monitors the vehicle doors, liftgate, hood, and theignition for unauthorized operation. The alarm ac-
tivates by sounding the horn, flashing the head-
lamps and the VTSS indicator lamp. The VTSS does
not prevent engine operation, this is done with the
Sentry Key Immobilizer Module (SKIM). Passive
arming occurs in one of two ways. Upon normal
vehicle exit by removing the ignition key, opening
the driver door, locking the doors with the power
lock, and closing the driver door, or by removing the
ignition key, opening the driver door, closing the
driver door, and locking the doors with the Remote
Keyless Entry (RKE) transmitter. The VTSS indi-
cator lamp will flash for approximately 15 seconds
during the arming process. If there is no interrup-
tion during the arming process, upon completion
the VTSS indicator lamp will flash at a slower rate.
When the BCM receives an input to trigger the
alarm, the BCM will control the outputs of the
headlamps, horn, and VTSS lamp for approxi-
mately 18 minutes.
Arming (Active and Passive)
Active arming occurs when the RKE transmitter
is used to lock the vehicle doors, whether the doors
are open or closed. The arming process is complete
only after all doors are closed.
Passive arming occurs when the ignition key is
removed, the driver door is opened, and the doors
are locked with the power door lock switch, and the
door is closed.
Disarming (Active and Passive)
Active disarming occurs when the RKE transmit-
ter is used to unlock the vehicle doors. This disarm-
ing will also halt the alarm once it has been acti-
vated.
Passive disarming occurs upon normal vehicle
entry (unlocking driver door with the key). This
disarming will also halt the alarm once it has been
activated.
Tamper Alert
The VTSS tamper alert will sound the horn three
times upon disarming to indicate a tamper condi-
tion has occurred.
Manual Override
The system will not arm if the doors are locked
using the manual lock control or if the locks are
actuated by an inside occupant after the doors are
closed.
Diagnosis
For complaints about the Vehicle Theft Alarm
triggering on its own, use the DRBIIItand read the
Last VTSS Cause status.
26
GENERAL INFORMATION

WARNING: BEFORE ROAD TESTING A
VEHICLE, BE SURE THAT ALL
COMPONENTS ARE REASSEMBLED.
DURING THE TEST DRIVE, DO NOT TRY TO
READ THE DRBIIITSCREEN WHILE IN
MOTION. DO NOT HANG THE DRBIIITFROM
THE REAR VIEW MIRROR OR OPERATE IT
YOURSELF. HAVE AN ASSISTANT
AVAILABLE TO OPERATE THE DRBIIIT.
5.0 REQUIRED TOOLS AND
EQUIPMENT
DRBIIIt(diagnostic read-out box)
Jumper wires
Ohmmeter
Voltmeter
Sentry Key Tester
Test Light
8310 Airbag System Load Tool
8443 SRS Airbag System Load Tool
Diagnostic Junction Port Tester 8339
6.0 GLOSSARY OF TERMS
ABSantilock brake system
ACMairbag control module
AECMairbag electronic control module
(ACM)
ASDMairbag system diagnostic module
(ACM)
AT Cautomatic temperature control
BCMbody control module
CABcontroller antilock brake
CMTCcompass/mini-trip computer
CPAconnector positive assurance
DABdriver airbag
DCHAdiesel cabin heater assist
(cabin heater)
DLCdata link connector
DTCdiagnostic trouble code
DRdriver
EBLelectric back lite (rear window de-
fogger)ECMEngine control module
EVICelectronic vehicle information center
FCMfront control module
GCCGulf Coast Countries
HVACheater ventilation, air conditioning
IPMintelligent power module
LDUlower drive unit
LHDLeft Hand Drive
MICmechanical instrument cluster
MTCmanual temperature control
MSMMmemory seat/mirror module
OBDon board diagnostics
ODOodometer
ORCoccupant restraint controller
PA Bpassenger airbag
PASSpassenger
PCIProgrammable Communication In-
terface (vehicle communication bus)
PCMpowertrain control module
PDCpower distribution center
PLGpower liftgate
PLGMpower liftgate module
PSDpower sliding door
PSDMpower sliding door module
PWMpulse width modulated
RHDRight Hand Drive
RKEremote keyless entry
SABseat airbag
SBTseat belt tensioner
SIACMside impact airbag control module
SKIMsentry key immobilizer module
SKISsentry key immobilizer system
SQUIBalso called initiator (located inside
airbag)
SRSsupplemental restraint system
TCMtransmission control module
VFDvacuum fluorescent display
VTSSvehicle theft security system
30
GENERAL INFORMATION

Symptom:
SKIM MESSAGES NOT RECEIVED
When Monitored and Set Condition:
SKIM MESSAGES NOT RECEIVED
When Monitored: With the ignition in run, and the IOD fuse installed.
Set Condition: The BCM does not receive any messages from the Sentry Key Immobilizer
Module (SKIM) for at least 5 seconds.
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH THE SENTRY KEY IMMOBILIZER MODULE
BODY CONTROL MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, attempt to communicate with the SKIM.
Was the DRB able to I/D or communicate with the SKIM?All
Ye s®Go To 2
No®Refer to the Communication category for the related symptom(s).
Perform BODY VERIFICATION TEST - VER 1.
2 With the DRB, erase DTC's.
Cycle the ignition switch from off to on and wait approximately 1 minute.
With the DRB, read DTC's.
Did this DTC reset?All
Ye s®Replace the Body Control Module.
Perform BODY VERIFICATION TEST - VER 1.
No®Test Complete.
371
COMMUNICATION

Symptom:
*BUS +/- SIGNALS OPEN FROM SENTRY KEY IMMOBILIZER MOD-
ULE
POSSIBLE CAUSES
ATTEMPT TO COMMUNICATE WITH THE BCM
GROUND CIRCUIT OPEN
IGNITION SWITCH OUTPUT CIRCUIT OPEN
FUSED B(+) CIRCUIT OPEN
OPEN PCI BUS CIRCUIT
SENTRY KEY IMMOBILIZER MODULE
TEST ACTION APPLICABILITY
1 Turn the ignition on.
With the DRB, enter Body then Body Computer.
Was the DRB able to I/D or communicate with the BCM?All
Ye s®Go To 2
No®Refer to the symptom list for problems related to no communica-
tion with the BCM.
Perform SKIS VERIFICATION.
2 Turn the ignition off.
Disconnect the SKIM harness connector.
Measure the resistance between ground and the ground circuit.
Is the resistance below 5.0 ohms?All
Ye s®Go To 3
No®Repair the ground circuit for an open.
Perform SKIS VERIFICATION.
3 Turn the ignition off.
Disconnect the SKIM harness connector.
Turn the ignition on.
Using a 12-volt test light connected to ground, probe the Ignition Switch Output
circuit.
Is the test light illuminated?All
Ye s®Go To 4
No®Repair the Ignition Switch Output circuit for an open.
Perform SKIS VERIFICATION.
4 Turn the ignition off.
Disconnect the SKIM harness connector.
Using a 12-volt test light connected to ground, probe the Fused B(+) circuit.
Is the test light illuminated?All
Ye s®Go To 5
No®Repair the Fused B+ circuit for an open.
Perform SKIS VERIFICATION.
377
COMMUNICATION