engine CHRYSLER VOYAGER 2001 Service Manual

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
INTERNAL EEPROM WRITE ERROR......................................927
INTERNAL TRANSMIT FAILURE..........................................928
INTERNAL ULTRASONIC FAULT.........................................929
LOOPBACK ERROR....................................................935
NO VALID MESSAGES RECEIVED........................................936
PCI BUS SHORTED TO BATTERY........................................937
PCI BUS SHORTED TO GROUND........................................938
PCM MESSAGES NOT RECEIVED........................................939
VEHICLE THEFT ALARM INDICATOR OUTPUT OPEN.......................940
VEHICLE THEFT ALARM INDICATOR OUTPUT SHORT......................941
*ALARM TRIPS ON ITS OWN............................................942
*HOOD DOES NOT TRIP VTSS..........................................943
*LEFT FRONT DOOR DOES NOT TRIP VTSS..............................944
*LEFT SLIDING DOOR DOES NOT TRIP VTSS.............................945
*LIFTGATE DOES NOT TRIP VTSS.......................................946
*REPEATER LAMPS INOPERATIVE WITH ALARM...........................947
*RIGHT FRONT DOOR DOES NOT TRIP VTSS.............................948
*RIGHT SLIDING DOOR DOES NOT TRIP VTSS............................949
*VTSS INDICATOR INOPERATIVE........................................950
*VTSS INDICATOR LAMP INOPERATIVE...................................951
*VTSS SIREN INOP....................................................952
*VTSS WILL NOT ARM..................................................955
WINDSHIELD WIPER & WASHER
FR WIPER HI-LO RELAY OPEN..........................................956
FR WIPER HI-LO RELAY SHORT TO BATT.................................958
FRONT WASH SWITCH INPUT STUCK....................................959
FRONT WASHER OUTPUT OPEN........................................961
FRONT WIPER NOT PARKED............................................963
FRONT WIPER ON RELAY OPEN........................................965
FRONT WIPER ON RELAY SHORT TO BATT...............................966
FRONT WIPER PARK SWITCH SHORT TO GND............................967
FRONT WIPER SWITCH MUX INPUT OPEN................................969
FRONT WIPER SWITCH MUX INPUT SHORT TO GROUND...................971
HEADLAMP WASHER RELAY OPEN......................................973
HEADLAMP WASHER RELAY SHORT TO BATT.............................975
REAR WASH SWITCH INPUT STUCK.....................................976
REAR WASHER OUTPUT OPEN.........................................978
REAR WIPER OUTPUT OPEN...........................................980
REAR WIPER OUTPUT SHORT TO GROUND..............................982
REAR WIPER SWITCH MUX INPUT OPEN.................................984
REAR WIPER SWITCH MUX INPUT SHORT TO GROUND....................986
VERIFICATION TESTS
VERIFICATION TESTS..................................................988
8.0 COMPONENT LOCATIONS..............................................995
8.1AIRBAG SYSTEM.................................................995
8.2BODY CONTROL MODULE.........................................996
8.3ENGINE CONTROL MODULE.......................................996
8.4HEATING & A/C...................................................996
8.4.1ACTUATORS ± FRONT LHD...............................996
xviii

TABLE OF CONTENTS - Continued
DIAGNOSTIC JUNCTION PORT - BLACK 16 WAY..........................1036
DOSING PUMP - BLACK 2 WAY.........................................1036
DRIVER AIRBAG C1 - BROWN 2 WAY....................................1036
DRIVER AIRBAG C2 - BLACK 2 WAY.....................................1036
DRIVER BLEND DOOR ACTUATOR (ATC) - GRAY 2 WAY...................1037
DRIVER BLEND DOOR ACTUATOR (MTC) - GRAY 2 WAY...................1037
DRIVER DOOR LOCK SWITCH - BLACK 3 WAY...........................1037
DRIVER SEAT BELT SWITCH - WHITE 2 WAY.............................1037
DRIVER SEAT BELT TENSIONER-2WAY................................1038
ELECTRIC WIPER DE-ICER C1 - WHITE 2 WAY...........................1038
ELECTRIC WIPER DE-ICER C2 - WHITE 2 WAY...........................1038
ENGINE CONTROL MODULE C1 (DIESEL) - BLACK 81 WAY.................1039
ENGINE CONTROL MODULE C2 (DIESEL) - BLACK 40 WAY.................1041
EVAPORATOR TEMPERATURE SENSOR - BLACK 2 WAY...................1041
FRONT BLOWER MODULE C1 (ATC) - BLACK 4 WAY......................1042
FRONT BLOWER MODULE C2 (ATC) - BLACK 2 WAY......................1042
FRONT READING LAMPS/SWITCH - BLACK 6 WAY........................1042
GLOVE BOX LAMP - BLUE 2 WAY.......................................1042
HALO LAMP - BLUE 2 WAY.............................................1042
HEADLAMP SWITCH - BLACK 13 WAY...................................1043
HEADLAMP WASHER PUMP MOTOR (BUILT-UP-EXPORT) - BLACK 2 WAY. . . .1043
IGNITION SWITCH - BLACK 5 WAY......................................1043
INSTRUMENT CLUSTER - BLACK 13 WAY................................1044
INTELLIGENT POWER MODULE C1 - LT. GREEN/RED 20 WAY..............1044
INTELLIGENT POWER MODULE C2 - GREEN/BLUE 10 WAY................1045
INTELLIGENT POWER MODULE C3 (DIESEL) - YELLOW/RED 20 WAY........1045
INTELLIGENT POWER MODULE C3 (GAS) - NATURAL/RED 20 WAY..........1046
INTELLIGENT POWER MODULE C4 - BLUE 10 WAY.......................1046
INTELLIGENT POWER MODULE C5 - BLACK 4 WAY.......................1046
INTELLIGENT POWER MODULE C6 - NATURAL 10 WAY....................1047
INTELLIGENT POWER MODULE C7 - BLACK/RED 20 WAY..................1047
INTELLIGENT POWER MODULE C8 - ORANGE 10 WAY....................1048
INTELLIGENT POWER MODULE C9 - BLACK 10 WAY......................1048
LEFT B-PILLAR SWITCH - GRAY 3 WAY..................................1048
LEFT CINCH/RELEASE MOTOR (POWER SLIDING DOOR) - GRAY 4 WAY.....1048
LEFT CYLINDER LOCK SWITCH - BLACK 2 WAY..........................1049
LEFT DOOR SPEAKER - BLACK/RED 6 WAY..............................1049
LEFT FOG LAMP - WHITE 2 WAY.......................................1049
LEFT FRONT DOOR AJAR SWITCH (BASE) - BLACK 2 WAY.................1049
LEFT FRONT DOOR LOCK MOTOR/AJAR SWITCH (EXCEPT BASE) -
BLACK 4 WAY........................................................1050
LEFT FRONT PARK/TURN SIGNAL LAMP (EXCEPT BUILT-UP-EXPORT) -
BLACK 3 WAY........................................................1050
LEFT FULL OPEN SWITCH (POWER SLIDING DOOR) - BLACK 2 WAY........1050
LEFT HEADLAMP (EXCEPT BUILT-UP-EXPORT) - BLACK 3 WAY.............1050
LEFT HIGH BEAM LAMP (BUILT-UP-EXPORT) - BLACK 2 WAY...............1051
LEFT INSTRUMENT PANEL SPEAKER - BLACK 2 WAY.....................1051
LEFT LOW BEAM LAMP (BUILT-UP-EXPORT) - BLACK 2 WAY...............1051
LEFT PARK LAMP (BUILT-UP-EXPORT) - BLACK 2 WAY....................1051
LEFT POWER MIRROR - BLACK 12 WAY.................................1052
LEFT REAR PILLAR SPEAKER - BLACK 2 WAY............................1052
LEFT REAR READING LAMP (LUXURY) - GRAY 3 WAY.....................1052
LEFT REAR SPEAKER - BLACK/RED 6 WAY..............................1052
xxi

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

This feature dims the interior lighting (courtesy
lamps) gradually if the BCM does not receive any
new inputs that would cause the interior lamps to
remain on.
²PWM Instrument Panel Dimming
²Door Lock Inhibit
This feature disables the door lock functions if the
key is in the ignition and either front door is ajar.
Pressing the RKE lock/unlock button under these
conditions, result in normal lock/unlock activation.
²Power Sliding Door Switch Inputs
The BCM has 4 switch inputs for the power
sliding door feature: Located in the overhead con-
sole are the Left and Right side sliding door
switches to activate either or both sliding doors
under the proper conditions. Also are B-Pillar
switches located on the Left and Right B-pillar
posts.
²Power Liftgate Switch Input
The BCM has 1 Liftgate switch input located in
the overhead console
²Power Lockout Switch Input
The BCM has 1 Lockout switch that when en-
abled will disable the B-Pillar sliding door switches
from activating either sliding door when depressed.
When replacing a body control module there are 2
modules available, a Base and a Midline. The
Midline controller is used on vehicles that have
Power Door Locks. If a vehicle is equipped with the
Vehicle Theft Security System, the midline control-
ler becomes a premium when the theft feature is
enabled.
NOTE: DO NOT SWAP THE BODY CONTROL
MODULE BETWEEN VEHICLES OR BODY
CONTROL MODULES OFF THE SHELF.
Engineering does not recommend that service,
dealers or the plant swap Body Control Modules
(BCM) between vehicles or off the shelf. The BCM
has internal diagnostic capability that assists in
diagnosing the system. When an ªOpenº or a
ªShortº circuit exists, the diagnostic tool can be
used to read the BCM codes. The codes are very
descriptive in identifying the appropriate feature
that has faulted.
3.4 CHIME WARNING SYSTEM
The BCM monitors the door/liftgate ajar
switches, multifunction switches, headlight switch,
ignition switch, PCI bus, and the diagnostic tool to
perform various chime operations. The BCM uses a
low-side driver to control the chime located in the
cluster.
The chime system provides the Driver with warn-
ing chimes for:
²Seat belt
²Exterior lights on
²Key-in Ignition
²Key-in Accessory
²Engine temperature critical
²Low washer fluid
²Turn signals on
²Dome light on
²Low oil pressure
²Any warning lamp announcement
²High-speed warning Gulf Coast Countries (GCC)
only
The output sound intensity of the chime is ap-
proximately 72 decibels.
3.4.1 CHIME PRIORITY
The following list indicates the priority of the
chime when more than one chime is active at the
same time:
²Seat belt warning
²High-speed warning Gulf Coast Countries (GCC)
only
²Turn signal on
²Chime request
²Warning lamp announcement
The cluster is responsible to set priority on all
warning lamp announcement chimes.
3.4.2 CHIME ON CONDITIONS
The following is a list of the chime warnings and
when they will sound.
Driver 's Seat
belt Unbuckled:Sounds for approximately 662
seconds when the igntion is turned
on and driver 's seat belt is not
buckled, as a reminder to the
driver to buckle the seat belt.
Exterior Lights
On:Ignition is in the lock position,
the driver door is ajar, and the
headlight switch is left in any
position, other than auto or off.
The chime will sound as a warn-
ing to the driver until one of the
above conditions is removed or
until the battery protection time
of 3 minutes has expired.
Key-In Ignition: Ignition is in the lock position,
driver door is ajar and the key is
in the ignition. The chime will
sound until one of the above con-
ditions is removed or until the
battery protection time of 15 min-
utes has expired.
9
GENERAL INFORMATION

Turn Signal On: When the BCM detects a turn
signal input continuously for
1.0mile/0.6km and the vehicle
speed is greater than 15 mph/
24kph, the chime will sound until
the specific turn signal is can-
celled.
Dome Lights On: Ignition is in the lock position,
driver door ajar, and the dome
light switch is left in the on
position. The chime will sound
until one of the above conditions
is removed or until the battery
protection time of 15 minutes has
expired.
Low Oil Pres-
sure:The chime will sound when the
engine is operating and the oil
pressure drops below 4psi/27.5kPa.
Engine
Temperature
Critical:The chime will sound when the
engine is operating and the cool-
ant temperature exceeds 252ÉF/
122Cor 234É/112C(diesel).The
chime is continuous at 257ÉF/
125C and will chime for 4 min-
utes and stop if the temperature
drops below 255ÉF/123C.
Low Washer
FluidThe chime will sound when the
washer fluid drops below a spe-
cific level.
Warning Lamp
Announcement:A chime will sound to alert the
driver to scan the instrument
panel to see which warning lamp
is illuminated. The door/liftgate
ajar warning lamp will appear
without a chime if the vehicle is
running and a door or the liftgate
is opened. A chime will sound if
the door or liftgate is still open
and the vehicle speed is greater
than 4mph/6kph.
High-speed
warning Gulf
Coast Countries
(GCC) onlyThe chime will sound, acting as a
warning to the driver that the
vehicle speed has exceed
75mph62/120kph63.3.4.3 WARNING LAMP ANNOUNCEMENT
Low Fuel Lamp: The cluster will request a single
chime after the indicator is illu-
minated.
Volt Lamp: The cluster will request a single
chime after the indicator is illu-
minated.
Oil Pressure
Lamp:The cluster will request a single
chime after illuminating the in-
dicator above 450rpm vehicle op-
eration.
Headlight Out
Lamp:The cluster will request a single
chime after the indicator is illu-
minated.
Liftgate Ajar
Lamp:The BCM determines when to
chime for liftgate ajar.
Fasten Seat Belt
Lamp:The BCM will request five chimes
from the MIC when the ignition
is turned to the unlock/run/start
positions if the driver seat belt is
not buckled.
Check Engine
Lamp:The cluster will request a single
chime after the indicator is illu-
minated.
Low Washer
Fluid Lamp:The cluster will request a single
chime after the indicator is illu-
minated.
Engine Tempera-
ture Lamp:The cluster will request a single
chime when the indicator is first
illuminated at 252ÉF/122C.
3.4.4 OTHER CHIME ON CONDITIONS
Bulb Check: The chime will sound three times
during bulb check.
Programming of
an Additional
Key Fob:A double cluster chime will sound,
which signals that the program
mode has been initiated.
Programming for
Rolling Door
Locks:When the programming has been
completed, a single tone from the
chime system, will occur.
10
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

3.7.6 EXTERIOR LIGHTING BATTERY
SAVER
The BCM monitors the status of, and controls, the
Park Lamps, Headlamps and Fog Lamp relays. If
any exterior lamps are left ON after the ignition is
turned OFF, the BCM will turn them OFF after 3
minutes.
3.7.7 AUTO HEADLAMPS
This feature is available on vehicles equipped
with both the Electrocromatic Mirror (ECM) and
the Compass/Mini-Trip Computer (CMTC). When
the BCM detects a day/night signal from the CMTC,
an ECM is present and Auto Headlamp mode is
selected.
3.8 FRONT CONTROL MODULE
The Front Control Module (FCM) is an electrical
control and interface center located in the engine
compartment. When it is mated to the Power Dis-
tribution Center (PDC), it is referred to as the
Intelligent Power Module (IPM). The IPM, with its
fuses and relays provides power and signal distri-
bution throughout most of the vehicle. The FCM
receives both hard wire and digital electronic inputs
from the vehicle electrical system through the PDC.
Based on these inputs and the ignition switch
position, it provides direct power feeds and relay
control to some of the vehicles' most critical electri-
cal systems.
The Front Control Module provides the following
features:
Controlled power feeds:
²Front airbag system
²Side airbag system
²Headlamp power
²EATX module power (4 speed only)
²Front washer motor
²Rear washer motor
²Brake shift interlock system
Relay controls:
²Fog lamp relay (when equipped)
²Park lamp relay
²Front wiper on relay
²Front wiper high/low relay
²Accessory relay
²Horn relay
²Front & rear blower relay
²Name brand speakers (NBS) relay
²Electronic back light (EBL) run only relay
²Cabin heater relayElectrical inputs:
²Headlamp battery supplies1&2
²Module battery supply
²Power ground
²Ignition switch RUN or START position status
²Ignition switch START only status
²PCI Bus
²Stop lamp switch
²Horn switch
²Back-up switch
²Wiper park switch
²Washer fluid level switch
²Brake fluid level switch
²Ambient temperature sensor
²Right park lamp outage
²Left park lamp outage
²Battery IOD
²Battery (+) connection detection
²Flash reprogramming voltage
3.8.1 CONTROLLED POWER FEEDS
Front airbag system
The FCM provides power to the Occupant Re-
straint Control (ORC) system through two ªfuse-
lessº circuits (ORC RUN/START, and ORC RUN
only). These circuits are electronically controlled
and continuously monitored for malfunctions.
Power is supplied while the ignition switch is in the
RUN and START positions on pin 48 of the FCM
connector, and in the RUN only position on pin 29.
Side airbag system
The FCM provides power to the Side Impact
Airbag Control Module (SIACM) system through
one ªfuselessº circuit. This circuit is electronically
controlled and continuously monitored for malfunc-
tions. Power is supplied in the ignition RUN and
START positions on pin 28 of the FCM connector.
Headlamp power
The headlamp switch is a direct input to the
BCM. The BCM sends a PCI 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 continu-
ously monitored for malfunctions. Power is supplied
to each filament in a separate circuit (RH low on pin
6, RH high on pin 4, LH low on pin 3 and LH high
on pin 5). For vehicles equipped with Daytime
Running Lamps (DRL), the FCM electronically
steps down the headlamp voltage to provide the
desired illumination.
13
GENERAL INFORMATION

the CPA is not properly engaged, a voltage on pin 38
will be interpreted as an unseated connector and a
fault will set.
Flash programming voltage Ð20 volt input on
pin 42. When a DRBIIItis connected and the
proper flash reprogramming sequence is selected,
the 20 volt signal will be applied through pin 42.
3.9 HEATING & A/C
3.9.1 AUTOMATIC TEMPERATURE
CONTROL (ATC)
3.9.1.1 CABIN HEATER
For vehicles equipped with a diesel engine, a
Cabin Heater is used in conjunction with the HVAC
system. The Cabin Heater is designed to supply the
vehicle's occupants with heat prior to the engine
reaching operating temperature. For additional in-
formation on this system, refer to Cabin Heater
under General Information and Diagnostic Proce-
dures in this manual.
3.9.1.2 SYSTEM OPERATION
The Automatic Temperature Control (ATC) sys-
tem provides fully adjustable three zone climate
control; Driver front zone, Passenger Front zone
and Rear zone. The following is a list of ATC
controls and features:
± a POWER button which allows the operator to
turn the system completely off.
± AUTO HIGH/LOW switch allows the operator
to select what rate (fan speed) the system will
provide the selected comfort level.
± DRIVER, REAR and PASSENGER rocker
switches to select desired temperature for each
zone.
± Recirculation button allows cooling air to be
recirculated which maximizes cooling ability.
± A/C select button allows the operator to turn
the A/C compressor off.
± Defroster button allows the operator to turn on
the defroster independently during automatic
control.
± Fan control rotary switch for selecting fan
speed.
± Mode rotary switch for selecting heating/
cooling direction.
± REAR SYSTEM rotary switch for activating
the Rear ATC Switch allowing intermediate
passenger control over rear climate control.
3.9.1.3 BLOWER MOTOR OPERATION
The Automatic Temperature Control (ATC) front
and rear blower control provides continuously vari-
able control of air flow rate to meet occupant
comfort requirements. Pulse width modulation of
the blower motor power allows the front and rear
blower to operate at any speed from off to full speed.
When front or rear blower operation is required, the
ATC sends a PCI Bus message to the Front Control
Module (FCM) requesting blower relay ON. The
FCM provides a ground for the front and rear
blower motor relay coils, activating both relays. The
front and rear blower relays provide 12 volts to
their respective blower motor power modules. Each
module provides a 12 volt blower motor control
signal to the ATC. The ATC provides a pulse width
modulated (duty-cycle) ground signal to this circuit
based on climate requirements. The higher voltage
on the signal circuit (less duty-cycle ground) the
lower the blower speed request. The lower voltage
on the signal circuit (more duty-cycle ground) the
higher the blower speed request.
3.9.1.4 INFRARED SENSORS
The ATC system uses infrared (I/R) sensors to
monitor and control oocupant comfort levels. This
sensing system replaces interior air temperature
and solar sensors which required complex control
programs to maintain occupant comfort levels. The
front I/R sensor is located in the instrument panel
center bezel outlet. The rear I/R sensor is located in
the rear overhead mounted ATC switch.
3.9.1.5 REAR ATC SWITCH
The rear ATC switch is mounted in the headliner.
The switch contains a rotary adjustment for fan
speed, a rotary adjustment for mode selection, a
push button switch for temperature selection and a
digital display of the selected temperature.
3.9.1.6 COOLDOWN TESTING
The ATC provides a feature referred to as a
Cooldown Test. This test is initiated using the
DRBIIItand is designed to check the performance
of the air conditioning system. The ATC will not
perform this test if the ambient air temperature is
below 12ÉC (53ÉF). During the test, the ATC com-
pares the ambient air temperature to the evapora-
tor temperature sensor. To pass the cooldown test,
the evap temperature sensor must drop -6ÉC (20ÉF)
below ambient temperature within 2 minutes of
start of test. At the completion of the cooldown test
the DRBIIItwill display one of the following mes-
sages indicating test outcome:
± Cooldown Test Passed
± Cooldown Test Failed
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GENERAL INFORMATION

± Evap Temp Sensor Shorted
± Evap Temp Sensor Open
± A/C Pressure Too Low
± A/C Pressure Too High
± Invalid Conditions for Cooldown Test, Evap
Temperature Too Low
If a message other than Cooldown Test Passed
occurs, refer to the appropriate symptom for diag-
nosis.
3.9.1.7 ACTIVE AND STORED TROUBLE
CODES
The Automatic Temperature Control (ATC) is
capable of storing Active and Stored trouble codes.
Active codes indicate a current fault in the system.
Stored codes indicate that a problem has occurred
in the system, however is not currently present.
Active codes cannot be erased until the problem
causing the code has been repaired. At this time the
Active code is converted to a Stored code, which can
be erased using the DRBIIIt.
3.9.2 MANUAL TEMPERATURE CONTROL
3.9.2.1 SYSTEM AVAILABILITY
Depending on the model, either a Single-Zone Air
Conditioning System or a Dual-Zone Air Condition-
ing System is currently available in these vehicles.
3.9.2.2 CABIN HEATER
For Vehicles equipped with a diesel engine, a
Cabin Heater is used in conjunction with the HVAC
system. The Cabin Heater is designed to supply the
vehicle's occupants with heat prior to the engine
reaching operating temperature. For additional in-
formation on this system, refer to Cabin Heater
under General Information and Diagnostic Proce-
dures in this manual.
3.9.2.3 ZONE CONTROL ± SINGLE-ZONE
The Single-Zone Air Conditioning System main-
tains incoming air temperature, airflow, fan speed,
and fresh air intake for the entire vehicle from the
instrument panel mounted A/C ± Heater Control
Module. The full range of temperature that the
system can produce in any mode for the entire
vehicle is available by positioning the blend control
to the desired range.
3.9.2.4 ZONE CONTROL ± DUAL-ZONE
The Dual-Zone Air Conditioning System main-
tains incoming air temperature, airflow, fan speed,
and fresh air intake for the entire vehicle from the
instrument panel mounted A/C ± Heater ControlModule. In addition, this system provides com-
pletely independent side-to-side control of incoming
air temperature. The full range of temperature that
the system can produce in any mode is available on
either side of the vehicle by positioning the inde-
pendent driver and passenger blend controls to the
desired range.
3.9.2.5 AIR DISTRIBUTION
The HVAC unit has five fully adjustable instru-
ment panel outlets. Side-window demister outlets
in the instrument panel eliminate door ducts and
door-to-instrument panel seals. A single, central
mounted outlet delivers air for defrosting the wind-
shield. Air exhausters allow air entering at the
front of the vehicle to flow out the back to the rear
occupants. Mid-cabin comfort control directs only
cooling air flow to the intermediate seat occupants
through outlets at the rear of each front door trim
panel. Air is supplied to these outlets from the
instrument panel through ducts in the doors that
use molded seals at the instrument panel to prevent
air leakage. Wide outlets under the front seats with
directional dividers distribute heated air across the
floor to the intermediate seat occupants. Ducts in
the center of the vehicle under the carpet deliver air
from the HVAC unit to these outlets. Models
equipped with Dual-Zone A/C systems also include
a dust and odor air filter installed in the HAVC
housing.
3.9.2.6 DOOR ACTUATORS
The electric door actuators are a two-wire design.
Each door actuator uses a similar connector wired
directly to the A/C ± Heater Control Module. Single-
Zone systems have one blend door actuator, one
mode door actuator, and one recirculation door
actuator. Dual-Zone systems have two blend door
actuators, one mode door actuator, and one recircu-
lation door actuator. All of the door actuators are
accessible from the vehicle's interior.
3.9.2.7 DOOR ACTUATOR CONTROL
The A/C ± Heater Control Module knows the
number of operating actuator revolutions required
for full door travel as well as the number of actuator
commutator pulses per revolution. Using these pa-
rameters, the A/C ± Heater Control Module runs
the actuator for the number of commutator pulses
that correspond to the desired door position. To
maintain accuracy, the system recalibrates itself
periodically at known zero and full travel condi-
tions.
17
GENERAL INFORMATION