
FOREWORD
The information contained in this service manual has been prepared for the professional automotive tech-
nician involved in daily repair operations. Information describing the operation and use of standard and
optional equipment is included in the Owner's Manual provided with the vehicle.
Information in this manual is divided into groups. These groups contain description, operation, diagnosis,
testing, adjustments, removal, installation, disassembly, and assembly procedures for the systems and compo-
nents. To assist in locating a group title page, use the Group Tab Locator by clicking to the following page. The
first page of the group has a contents section that lists major topics within the group.
A Service Manual Comment form is included at the rear of this manual. Use the form to provide
DaimlerChrysler Corporation with your comments and suggestions.
Tightening torques are provided as a specific value throughout this manual. This value represents the
midpoint of the acceptable engineering torque range for a given fastener application. These torque values are
intended for use in service assembly and installation procedures using the correct OEM fasteners. When
replacing fasteners, always use the same type (part number) fastener as removed.
DaimlerChrysler Corporation reserves the right to change testing procedures, specifications, diagnosis,
repair methods, or vehicle wiring at any time without prior notice or incurring obligation.

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

1.0 INTRODUCTION
The procedures contained in this manual include
all the specifications, instructions and graphics
needed to diagnose 2001 body system problems. The
diagnostics in this manual are based on the failure
condition or symptom being present at the time of
diagnosis.
Please follow the recommendations below when
choosing your diagnostic path.
1. First make sure the DRBIIItis communicating
with the appropriate modules; i.e., if the
DRBIIItdisplays a ªNo Responseº or a ªBus6
Signals Openº condition, you must diagnose that
first.
2. Read DTC's (diagnostic trouble codes) with the
DRBIIIt.
3. If no DTC's are present, identify the customer
complaint.
4. Once the DTC or customer complaint is identi-
fied, locate the matching test in the Table of
Contents and begin to diagnose the symptom.
All component location views are in Section 8.0. All
connector pinouts are in Section 9.0. All schematics
are in Section 10.0. All Charts and Graphs are in
Section 11.0.
An * placed before the symptom description indi-
cated a customer complaint.
When repairs are required, refer to the appropri-
ate service information for the proper removal and
repair procedure.
Diagnostic procedures change every year. New
diagnostic systems may be added: carryover systems
may be enhanced. READ THIS MANUAL BEFORE
TRYING TO DIAGNOSE A VEHICLE DIAGNOS-
TIC TROUBLE CODE. It is recommended that you
review the entire manual to become familiar with all
the new and changed diagnostic procedures.
This book reflects many suggested changes from
readers of past issues. After using this book, if you
have any comments or suggestions, please fill out
the form in the back of this book and mail it back to
us.
1.1 SYSTEM COVERAGE
This diagnostic procedures manual covers all
2001 Chrysler Voyager and Caravan vehicles. This
diagnostic procedures manual also covers both left
hand drive (LHD) and right hand drive (RHD)
vehicles. There may be some slight differences in
the location views of components. If the location
views shown are on a LHD vehicle, a RHD vehicle
will be symmetrically opposite.
1.2 SIX-STEP TROUBLESHOOTING
PROCEDURE
Diagnosis of the body system is done in six basic
steps:
²verification of complaint
²verification of any related symptoms
²symptom analysis
²problem isolation
²repair of isolated problem
²verification of proper operation
2.0 IDENTIFICATION OF
SYSTEM
The vehicle systems that are part of the ªbodyº
system are:
²Airbag
²Audio
²Cabin Heater
²Chime
²Communication
²Door Ajar System
²Electrically heated system
²Exterior lighting
²Heating and A/C
²Instrument Cluster
²Interior Lighting
²Manual Temperature Control
²Memory Seat
²Overhead Console
²Power Door Lock/RKE
²Power Folding Mirrors
²Power Sliding Doors
²Power Liftgate
²Power windows
²Vehicle Theft Security System (VTSS)
²Windshield Wiper and Washer
3.0 SYSTEM DESCRIPTION AND
FUNCTIONAL OPERATION
The body system on the 2001 RG consists of a
combination of modules that communicate over the
PCI bus (Programmable Communication Interface
multiplex system). Through the PCI bus, informa-
tion about the operation of vehicle components and
circuits is relayed quickly to the appropriate mod-
ule(s). All modules receive all the information trans-
1
GENERAL INFORMATION

Ifneither of the following codes is an active code:
ACTIVE DTC SQUIB STATUS
Driver squib 1 open Status of Airbag is
Driver Squib 2 open Unknown.
3.1.2 CLOCKSPRING
The clockspring is mounted on the steering col-
umn behind the steering wheel. This assembly
consist of a plastic housing which contains a flat,
ribbon-like, electrically conductive tape that winds
and unwinds with the steering wheel rotation. The
clockspring is used to maintain a continuous elec-
trical circuit between the instrument panel wiring
and the driver airbag, the horn, and the vehicle
speed control switches if equipped. The clockspring
must be properly centered when it is reinstalled on
the steering column following any service proce-
dure, or it could be damaged. The clockspring can-
not be repaired and it must be replaced.
3.1.3 PASSENGER AIRBAG
The airbag door in the instrument panel top cover
the glove box is the most visible part of the passen-
ger side airbag system. The airbag door has a living
hinge at the top, which is secured to the instrument
panel top cover. Located under the airbag door is
the airbag cushion and its supporting components.
The airbag module includes a housing to which the
cushion and hybrid inflators are attached and
sealed. The 2001 Minivan is equipped with front
passenger airbag with dual stage inflators that
include a small canister of highly compressed argon
gas. The ORC uses vehicle crash severity, front
passenger seat belt switch status (buckled or un-
buckled) inputs to determine the level of airbag
deployment. When supplied with the proper electri-
cal signal, the hybrid inflator or inflators discharge
the compressed gas it contains directly into the
cushion. The airbag module cannot be repaired, and
must be replaced if deployed or in any way dam-
aged.
WARNING: THE PASSENGER AIRBAG
MODULE CONTAINS ARGON GAS
PRESSURIZED TO 17236.89 Kpa (2500 PSI).
DO NOT ATTEMPT TO DISMANTLE AN
AIRBAG MODULE OR TAMPER WITH ITS
INFLATOR. DO NOT PUNCTURE,
INCINERATE, OR BRING INTO CONTACT
WITH ELECTRICITY. DO NOT STORE AT
TEMPERATURE EXCEEDING 93ÉC (200ÉF).
REPLACE AIRBAG SYSTEM COMPONENTS
ONLY WITH PARTS SPECIFIED IN THE
MOPAR PARTS CATALOG. SUBSTITUTE
PARTS MAY APPEAR INTERCHANGEABLE,
BUT INTERNAL DIFFERENCES MAY RESULT
IN INFERIOR OCCUPANT PROTECTION. THE
FASTENERS, SCREWS, AND BOLTS
ORIGINALLY USED FOR THE AIRBAG
SYSTEM COMPONENTS HAVE SPECIAL
COATINGS AND ARE SPECIFICALLY
DESIGNED FOR THE AIRBAG SYSTEM. THEY
MUST NEVER BE REPLACED WITH ANY
SUBSTITUTES. ANY TIME A NEW FASTENER
IS NEEDED, REPLACE IT WITH THE
CORRECT FASTENERS PROVIDED IN THE
SERVICE PACKAGE OR SPECIFIED IN THE
MOPAR PARTS CATALOG.
4
GENERAL INFORMATION

if the system is functioning properly. If the test
finds a problem the SIACM will set both active and
stored diagnostic trouble codes. If a DTC is active
the SIACM will request that the airbag warning
lamp be turned on. The results of the system test
are transmitted on the PCI Bus to the ORC once
each second or on change in lamp state. If the
warning lamp status message from the either SI-
ACM contains a lamp on request, the ORC will set
an active DTC. At the same time as the DTC is set
the ORC sends a PCI Bus message to the mechan-
ical instrument cluster (MIC) requesting the airbag
warning lamp be turned on. Observe all ORC warn-
ing and caution statements when servicing or han-
dling the SIACM. SIACM are not repairable and
must be replaced if they are dropped.
WARNING: THE AIRBAG SYSTEM IS A
SENSITIVE, COMPLEX ELECTRO-
MECHANICAL UNIT. BEFORE ATTEMPTING
TO DIAGNOSE OR SERVICE ANY AIRBAG
SYSTEM OR RELATED STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT
PANEL COMPONENTS YOU MUST FIRST
DISCONNECT AND ISOLATE THE BATTERY
NEGATIVE (GROUND) CABLE. WAIT TWO
MINUTES FOR THE SYSTEM CAPACITOR TO
DISCHARGE BEFORE FURTHER SYSTEM
SERVICE. THIS IS THE ONLY SURE WAY TO
DISABLE THE AIRBAG SYSTEM. FAILURE
TO DO THIS COULD RESULT IN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY. NEVER STRIKE OR
KICK THE AIRBAG CONTROL MODULE, AS
IT CAN DAMAGE THE IMPACT SENSOR OR
AFFECT ITS CALIBRATION. IF AN AIRBAG
CONTROL MODULE IS ACCIDENTALLY
DROPPED DURING SERVICE, THE MODULE
MUST BE SCRAPPED AND REPLACED WITH
A NEW UNIT.
The airbag warning lamp is the only point at
which the customer can observe symptoms of a
system malfunction. Whenever the ignition key is
turned to the run or start position, the MIC per-
forms a lamp check by turning the airbag warning
indicator on for 6-8 seconds. After the lamp check, if
the indicator turns on, it means that the ORC has
checked the system and found it to be free of
discernible malfuctions. If the lamp remains on,
there could be an active fault in the system or the
MIC lamp circuit may be internally shorted to
ground. If the lamp comes on and stays on for a
period longer than 6-8 seconds then goes off, there
is usually an intermittent problem in the system.
3.1.7 SEAT AIRBAGS (SAB)
The left and right seat airbag modules are located
in the outboard end of the front seat backs. The
airbag module contains a bag, an inflator (a small
canister of highly compressed argon gas) and a
mounting bracket. The seat airbag module cannot
be repaired and must be replaced if deployed or in
any way damaged. When supplied with the proper
electrical signal the inflator seals the hole in the
airbag cushion so it can discharge the compressed
gas it contains directly into the cushion. Upon
deployment, the seat back trim cover will tear open
and allow the seat airbag to fully deploy between
the seat and the door.
WARNING: SEAT AIRBAG CONTAINS ARGON
GAS PRESSURIZED TO OVER 17236.89 Kpa
(2500 PSI). DO NOT ATTEMPT TO
DISMANTLE AN AIRBAG MODULE OR
TAMPER WITH ITS INFLATOR. DO NOT
PUNCTURE, INCINERATE, OR BRING INTO
CONTACT WITH ELECTRICITY. DO NOT
STORE AT TEMPERATURE EXCEEDING 93ÉC
(200ÉF). REPLACE AIRBAG SYSTEM
COMPONENTS ONLY WITH PARTS
SPECIFIED IN THE CHRYSLER MOPAR
PARTS CATALOG. SUBSTITUTE PARTS MAY
APPEAR INTERCHANGEABLE, BUT
INTERNAL DIFFERENCES MAY RESULT IN
INFERIOR OCCUPANT PROTECTION. THE
FASTENERS, SCREWS, AND BOLTS
ORIGINALLY USED FOR THE AIRBAG
SYSTEM COMPONENTS HAVE SPECIAL
COATINGS AND ARE SPECIFICALLY
DESIGNED FOR THE AIRBAG SYSTEM. THEY
MUST NEVER BE REPLACED WITH ANY
SUBSTITUTES. ANY TIME A NEW FASTENER
IS NEEDED, REPLACE IT WITH THE
CORRECT FASTENERS PROVIDED IN THE
SERVICE PACKAGE OR SPECIFIED IN THE
MOPAR PARTS CATALOG.
3.1.8 ORC/SIACM DIAGNOSTIC TROUBLE
CODES
Airbag diagnostic trouble codes consist of active
and stored codes. If more than one code exists,
diagnostic priority should be given to the active
codes. Each diagnostic trouble code is diagnosed by
following a specific testing procedure. The diagnos-
tic test procedures contain step-by-step instructions
for determining the cause of the trouble codes. It is
not necessary to perform all of the tests in this book
to diagnose an individual code. Always begin by
reading the diagnostic trouble codes using the DRB.
Always begin diagnostic with the Table of Contents
6
GENERAL INFORMATION

section 7.0. This will direct you to the specific test(s)
that must be performed. Active diagnostic trouble
codes for the airbag system are not permanent and
will change the moment the reason for the code is
corrected. In certain test procedures within this
manual, diagnostic trouble codes are used as a
diagnostic tool.
3.1.9 ACTIVE CODES
The code becomes active as soon as the malfunc-
tion is detected or key-on, whichever occurs first. An
active trouble code indicates an on-going malfunc-
tion. This means that the defect is currently there
every time the airbag control module checks that
circuit or component. It is impossible to erase an
active code. Active codes automatically erase by
themselves when the reason for the code has been
corrected. With the exception of the warning lamp
trouble codes or malfunctions, when a malfunction
is detected, the airbag lamp remains lit for a mini-
mum of 12 seconds or as long as the malfunction is
present.
3.1.10 STORED CODES
Airbag codes are automatically stored in the
ORC's memory as soon as the malfunction is de-
tected. The exception is the Loss of Ignition Run
Only code which is an active code only. A stored code
indicates there was an active code present at some
time. However, the code currently may not be
present as an active code, although another code
could be active. When a trouble code occurs, the
airbag warning indicator illuminates for 12 seconds
minimum (even if the problem existed for less than
12 seconds). The code is stored, along with the time
in minutes it was active, and the number of times
the ignition has been cycled since the problem was
last detected. The minimum time shown for any
code will be one minute, even if the code was
actually present for less than one minute. Thus, the
time shown for a code will be one minute, even if the
code was actually present for less than one minute.
Thus, the time shown for a code that was present
for two minutes 13 seconds, for example, would be
three minutes. If a malfunction is detected a diag-
nostic trouble code is stored and will remain stored.
When and if the malfunction ceases to exist, an
ignition cycle count will be initiated for that code. If
the ignition cycle count reaches 100 without a
reoccurrence of the same malfunction, the diagnos-
tic trouble code is erased and that ignition cycle
counter is reset to zero. If the malfunction reoccurs
before the count reaches 100, then the ignition cycle
counter will be reset and diagnostic trouble code
will continue to be a stored code. If a malfunction is
not active while performing a diagnostic test proce-
dure, the active code diagnostic test will not locatethe source of the problem. In this case, the stored
code can indicate an area to inspect. If no obvious
problems are found, erase stored codes, and with
the ignition on wiggle the wire harness and connec-
tors, rotate the steering wheel from stop to stop.
Recheck for codes periodically as you work through
the system. This procedure may uncover a malfunc-
tion that is difficult to locate.
3.2 AUDIO SYSTEM
The following radios are all on the PCI Bus
system - RBB, RBK, RAZ, RAD, RBT, and RBY. The
remaining radio also available, the RAS, is NOT on
the PCI Bus. The PCI Bus inputs into the radio are
used for VF dimming, remote steering wheel con-
trols and cabin EQ preference. PCI Bus outputs
from the radio are used for the Name Brand
Speaker (NBS) relay activation, as well as cabin EQ
preference.
The RBB and RBK radios have the capability of
containing multiple vehicle unique equalization
curves (cabin EQ preferences) within the radio.
These curves will reside in the radio's flash memory.
The radio is capable of storing up to 20 unique
equalization curves. The latent curves can be se-
lected via the Front Control Module transmitting a
PCI Bus message to the radio in response to a radio
request for equalization message. Upon receipt of a
valid equalization select message response, the ra-
dio will switch to output the corresponding equal-
ization curve.
All the radios, except the RAS, are capable of
displaying faults and allowing certain actuation
tests through the use of the DRBIIIt. When at-
tempting to perform PCI Bus diagnostics, the first
step is to identify the radio in use in the vehicle.
When trouble shooting output shorts or ªoutputº
error messages, the following applies:
On radios without an external amplifier, the term
output refers to the path between the radio and the
speaker. This type of circuit can be monitored all
the way through the speaker connections by the
radio assembly. When the radio displays a shorted
output DTC with this type of system, the speaker,
radio, or wiring could be at fault. The output DTC
could refer to the front or rear output or a left or
right output. The reason for the difference is the
pairing of the output sections of the radio. Some are
paired left and right, others are paired front and
rear.
On radios with an external amplifier, the term
ªoutputº refers to the circuit between the radio
connector and the amplifier. The radio is capable of
monitoring only this portion and can tell nothing
about the circuit between the amplifier and the
speakers. Consequently, a shorted output DTC on
7
GENERAL INFORMATION

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

3.6 DOOR AJAR SYSTEM
The door ajar and liftgate ajar states are used as
inputs for the Body Control Module (BCM). The
BCM uses these inputs to determine exactly what
position the doors and liftgate are in. The DRBIIIt
will display the state of the door ajar and the
liftgate ajar switches in Inputs/Outputs. It's impor-
tant to note, that when any door, or the liftgate is
closed, the switch state on the DRBIIItwill show
OPEN. When any door, or the liftgate is open the
switch state on the DRBIIItwill show CLOSED.
During diagnosis, if a door or the liftgate is closed
and the DRBIIItdisplays the switch state as
CLOSED, it indicates a shorted ajar circuit. If the
door or the liftgate is open and the DRBIIItdis-
plays the switch state as OPEN, it indicates an
open ajar circuit.
3.7 EXTERIOR LIGHTING SYSTEM
3.7.1 HEADLAMP POWER
The headlamp switch is a direct input to the
BCM. The BCM sends a BUS message to the FCM
informing it of a headlamp switch status change.
The FCM then turns on power to the headlamps
through four ªfuselessº circuits. These circuits are
electronically controlled and continuously moni-
tored for malfunctions. Power is supplied to each
filament in a separate circuit. For vehicles equipped
with daytime running Lamps (DRL), the FCM elec-
tronically steps down the headlamp voltage to pro-
vide the desired illumination.
3.7.2 HEADLAMP SWITCH
The Headlamp Switch uses a multiplexed (MUX)
circuit to the Body Control Module (BCM). The
Headlamp Switch controls the Fog lamp relay, Park
lamps and the Low and High headlamps. The BCM
then sends a signal through the PCI Bus line to the
FCM as to what state the switch has selected. The
FCM energizes the high side output drivers to turn
ON the desired lamps.
3.7.3 PARK LAMP RELAY
The park lamp switch is a direct input to the
BCM. The BCM sends a BUS message to the FCM
informing it to turn on the park lamp relay. The
park lamp relay is then powered through low side
control of the FCM. This circuit is electronically
controlled and continuously monitored for malfunc-
tions.
3.7.4 FOG LAMP RELAY
The fog lamp switch is a direct input to the BCM.
The BCM sends a BUS message to the FCM inform-
ing it to turn on the fog lamp relay. The fog lamp
relay is then powered through low side control of
the FCM. This circuit is electronically controlled
and continuously monitored for malfunctions. Fog
lamp functionality is not equipped on all vehicles.
The FCM ªlearnsº that the vehicle is equipped with
fog lamps by reading the BCM BUS message.
3.7.5 FOG LAMPS
The BCM controls the operation of the fog lamp
relay that turns the fog lamps ON and OFF. The
Fog lamps can only be ON when the park and low
beams are ON. If the high beams are switched ON
then the Fog lamps will be automatically turned
OFF.
12
GENERAL INFORMATION