relay CHRYSLER VOYAGER 2001 Service Manual

REMOVAL
There are no repairs to be made to the fan or
shroud assembly. If the fan is warped, cracked, or
otherwise damaged, it must be replaced as an assem-
bly (Fig. 21).
(1) Remove the radiator upper crossmember. (Refer
to 23 - BODY/EXTERIOR/GRILLE OPENING REIN-
FORCEMENT - REMOVAL)
(2) Disconnect the radiator fan electrical connec-
tors.
(3) Remove radiator fan(s) retaining screw (Fig.
21).
(4) Remove the radiator fan(s) by lifting upward to
release from mounts.
INSTALLATION
(1) Install the radiator fan(s) into mounts and
attaching clips on the radiator.
(2) Install radiator fan(s) attaching screws (Fig.
21). Tighten to 5 N´m (45 in. lbs.).
(3) Connect the radiator fan(s) electrical connec-
tors.
(4) Install the radiator upper support crossmem-
ber. (Refer to 23 - BODY/EXTERIOR/GRILLE OPEN-
ING REINFORCEMENT - INSTALLATION)
(5) Install the upper radiator mounts to the cross-
member bolts, if removed. Tighten to 8 N´m (70 in.
lbs.).
(6) Install the radiator upper hose to the support
clip (2.4L engine).
RADIATOR FAN RELAY
DESCRIPTION
The radiator fan relay is a solid state type and is
located on the front bumper reinforcment (Fig. 22).
Refer to WIRING DIAGRAMS for a circuit sche-
matic.
OPERATION
The solid state radiator fan relay is controlled by
the Powertrain Control Module (PCM) by way of a
Pulse Width Modulated (PWM) signal. The relay con-
trol circuit supplies a 12 volt signal to the PCM. The
PCM then pulses the ground circuit to achieve fan on
time. The relay provides a voltage to the fan motors
which is proportional to the pulse width it receives
from the PCM. The duty cycle ranges from 30% for
low speed operation, then ramps-up to 100% for high
speed operation. This fan control system provides
infinitely variable fan speeds, allowing for improved
fan noise, A/C performance, better engine cooling,
and additional vehicle power.
To control operation of the relay, the PCM looks at
inputs from:
²Engine coolant temperature
²A/C pressure transducer
²Ambient temperature from the body controller
²Vehicle speed
²Transmission oil temperature
The PCM uses these inputs to determine when the
fan should operate and at what speed. For further
information on fan operation, (Refer to 7 - COOL-
ING/ENGINE/RADIATOR FAN - OPERATION).
REMOVAL
(1) Open hood.
(2) Disconnect and isolate the battery negative
cable.
(3) Remove the radiator crossmember to front fas-
cia closure panel.
(4) Disconnect the relay electrical connector (Fig.
22).
(5) Remove the rivet attaching the relay to the
front bumper beam (Fig. 22).
(6) Remove the relay.
INSTALLATION
CAUTION: The relay mounting location is designed
to dissipate heat. Ensure the relay is securely
attached to prevent relay ªthermalº shutdown and
relay damage, resulting in possible engine over-
heating.
Fig. 21 Radiator Fans
1 - SCREWS - RADIATOR FAN ATTACHING
2 - RADIATOR FAN - RIGHT
3 - MOUNT - RIGHT RADIATOR FAN
4 - CLIPS - RADIATOR FAN LOWER
5 - MOUNT - LEFT RADIATOR FAN
6 - RADIATOR FAN - LEFT
RSENGINE7-29
RADIATOR FAN (Continued)

(1) Position relay and install a new rivet (Fig. 22).
(2) Connect electrical connector to relay.
(3) Install closure panel and attaching screws.
(4) Connect negative cable to battery.
WATER PUMP - 2.4L
DESCRIPTION
The water pump has a cast aluminum body and
housing with a stamped steel impeller. The water
pump bolts directly to the block (Fig. 23). The cylin-
der block to water pump seal is provided by a rubber
O-ring. The water pump is driven by the engine tim-
ing belt.
OPERATION
The water pump is the heart of the cooling system.
The coolant is pumped through the engine block, cyl-
inder head, heater core, and radiator.
REMOVAL
(1) Disconnect negative cable from battery.
(2) Raise vehicle on a hoist.
(3) Remove the right inner splash shield.
(4) Remove the accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(5) Drain the cooling system. (Refer to 7 - COOL-
ING - STANDARD PROCEDURE)
(6) Support engine from the bottom and remove
right engine mount. (Refer to 9 - ENGINE/ENGINE
MOUNTING/RIGHT MOUNT - REMOVAL)
(7) Remove right engine mount bracket.
(8) Remove the timing belt. (Refer to 9 - ENGINE/
VALVE TIMING/TIMING BELT/CHAIN AND
SPROCKET(S - REMOVAL)
(9) Remove timing belt idler pulley.
(10) Hold camshaft sprocket with Special tool
C-4687 and adaptor C-4687-1 while removing bolt.
Remove both cam sprockets.
(11) Remove the timing belt rear cover (Refer to 9
- ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - REMOVAL) .
(12) Remove the generator and bracket (Fig. 24).
Fig. 22 Radiator Fan Relay
1 - FRONT FASCIA
2 - FAN RELAY
3 - RIVET
4 - A/C CONDENSER (FRONT SIDE)
Fig. 23 Water Pump
1 - CYLINDER BLOCK
2 - WATER PUMP
7 - 30 ENGINERS
RADIATOR FAN RELAY (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION...........................14
DIAGNOSIS AND TESTING.................15
COOLANT CONCENTRATION TESTING......15
STANDARD PROCEDURE..................15
COOLANT SERVICE.....................15
ADDING ADDITIONAL COOLANT...........15
COOLANT LEVEL CHECK................16
REFILLING COOLING SYSTEM............16
DRAINING COOLING SYSTEM.............16
COOLANT RECOVERY PRESS CONTAINER
DESCRIPTION...........................17
OPERATION.............................17
REMOVAL..............................18
INSTALLATION...........................18
ENGINE COOLANT TEMP SENSOR
DESCRIPTION...........................19
OPERATION.............................19
REMOVAL..............................19
INSTALLATION...........................19
ENGINE COOLANT THERMOSTAT
DESCRIPTION...........................19
OPERATION.............................19
REMOVAL..............................19
INSTALLATION...........................20
RADIATOR
DESCRIPTION...........................20
OPERATION.............................20
REMOVAL..............................20
INSTALLATION...........................21
RADIATOR DRAINCOCK
REMOVAL..............................22INSTALLATION...........................22
WATER PUMP
DESCRIPTION...........................22
OPERATION.............................22
REMOVAL..............................22
CLEANING..............................23
INSTALLATION...........................23
RADIATOR PRESSURE CAP
DESCRIPTION...........................24
OPERATION.............................24
DIAGNOSIS AND TESTING.................25
COOLING SYSTEM PRESSURE CAP........25
PRESSURE RELIEF TEST................25
CLEANING..............................25
INSPECTION............................26
RADIATOR FAN
DESCRIPTION...........................26
OPERATION.............................26
DIAGNOSIS AND TESTING.................26
RADIATOR FAN MOTOR.................26
REMOVAL..............................27
INSTALLATION...........................27
HOSE CLAMPS
DESCRIPTION...........................27
OPERATION.............................28
RADIATOR FAN RELAY
DESCRIPTION...........................28
OPERATION.............................28
COOLANT SYSTEM HOSES
REMOVAL..............................28
INSTALLATION...........................29
COOLANT
DESCRIPTION
Coolant flows through the engine water jackets
and cylinder heads absorbing heat produced by the
engine during operation. The coolant carries heat to
the radiator and heater core. Here it is transferred to
ambient air passing through the radiator and heater
core fins.
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The recommended mixture of 50/50
ethylene-glycol and water will provide protectionagainst freezing to -37 deg. C (-35 deg. F). The anti-
freeze concentrationmust alwaysbe a minimum of
44 percent, year-round in all climates.If percentage
is lower than 44 percent, engine parts may be
eroded by cavitation, and cooling system com-
ponents may be severely damaged by corrosion.
Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which
prevents freezing down to -67.7 deg. C (-90 deg. F). A
higher percentage will freeze at a warmer tempera-
ture. Also, a higher percentage of antifreeze can
cause the engine to overheat because the specific
heat of antifreeze is lower than that of water.
7a - 14 ENGINERG

INSPECTION
Hold the cap in your hand,top side up(Fig. 21).
The vent valve at the bottom of the cap should open.
If the rubber gasket has swollen, preventing the
valve from opening, replace the cap.
Hold the cleaned cap in your hand,upside down.
If any light can be seen between vent valve and the
rubber gasket, replace the cap.Do not use a
replacement cap that has a spring to hold the
vent shut.
A replacement cap must be of the type designed for
coolant reserve systems. This design ensures coolant
return to the radiator.
RADIATOR FAN
DESCRIPTION
The dual radiator fans are mounted to the back
side of the radiator (Fig. 22). The radiator fan consist
of the fan blade, electric motor and a support shroud
which are all serviced as an assembly.
OPERATION
RADIATOR FAN OPERATION CHART
COOLANT TEMPERATURE A/C PRESSURE
Fan Operation
Speeds:Initial Max Initial Max
Fan On: 104ÉC (220ÉF) 110ÉC (230ÉF) Fan
Speed Duty-Cycles
(Ramps-up) from
30% to 99%1,724 Kpa (250 psi) 2,068 Kpa (300 psi)
Fan Speed
Duty-Cycles
(Ramps-up) from
30% to 99%
Fan Off: 101ÉC (214ÉF) Fan Speed
Duty-Cycles
(Ramps-down) from
99% to 30%1,710 Kpa (248 psi) Fan Speed
Duty-Cycles
(Ramps-down) from
99% to 30%
DIAGNOSIS AND TESTING - RADIATOR FAN MOTOR
RADIATOR FAN DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
NOISY RADIATOR FAN 1. Fan blade loose. 1. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
2. Fan blade striking a surrounding
object.2. Locate point of fan blade contact
and repair as necessary.
3. Air obstructions at radiator or A/C
condenser.3. Remove obstructions and/or
clean debris.
4. Electric fan motor defective. 4. Replace fan assembly. (Refer to
7 - COOLING/ENGINE/RADIATOR
FAN - REMOVAL)
ELECTRIC FAN MOTOR DOES
NOT OPERATE1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor, or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Defective A/C pressure
transducer.2. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
7a - 26 ENGINERG
RADIATOR PRESSURE CAP (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
ELECTRIC RADIATOR FAN
OPERATES ALL THE TIME1. Fan relay, powertrain control
module (PCM), coolant temperature
sensor or wiring defective.1. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
2. Check for low coolant level. 2. Add coolant as necessary.
3. Defective A/C pressure
transducer.3. (Refer to Appropriate Diagnostic
Information) Repair as necessary.
REMOVAL
There are no repairs to be made to the fan or
shroud assembly. If the fan is warped, cracked, or
otherwise damaged, it must be replaced as an assem-
bly (Fig. 22).
(1) Remove the radiator upper crossmember. (Refer
to 23 - BODY/EXTERIOR/GRILLE OPENING REIN-
FORCEMENT - REMOVAL)
(2) Disconnect the radiator fan electrical connec-
tors.
(3) Remove radiator fan(s) retaining screw (Fig.
22).
(4) Remove the radiator fan(s) by lifting upward to
release from mounts.
INSTALLATION
(1) Install the radiator fan(s) into mounts and
attaching clips on the radiator.
(2) Install radiator fan(s) attaching screws (Fig.
22). Tighten to 5 N´m (45 in. lbs.).
(3) Connect the radiator fan(s) electrical connec-
tors.
(4) Install the radiator upper support crossmem-
ber. (Refer to 23 - BODY/EXTERIOR/GRILLE OPEN-
ING REINFORCEMENT - INSTALLATION).(5) Install the upper radiator mounts to the cross-
member bolts, if removed. Tighten to 8 N´m (70 in.
lbs.).
(6) Install the radiator upper hose to the support
clip (2.4L engine).
HOSE CLAMPS
DESCRIPTION - HOSE CLAMPS
The cooling system uses spring type hose clamps.
If a spring type clamp replacement is necessary,
replace with the original Mopartequipment spring
type clamp.
CAUTION: A number or letter is stamped into the
tongue of constant tension clamps. If replacement
is necessary, use only a original equipment clamp
with matching number or letter (Fig. 23).
Fig. 22 Radiator Fans
1 - SCREWS - RADIATOR FAN ATTACHING
2 - RADIATOR FAN - RIGHT
3 - MOUNT - RIGHT RADIATOR FAN
4 - CLIPS - RADIATOR FAN LOWER
5 - MOUNT - LEFT RADIATOR FAN
6 - RADIATOR FAN - LEFT
Fig. 23 Spring Clamp Size Location
1 - SPRING CLAMP SIZE LOCATION
RGENGINE7a-27
RADIATOR FAN (Continued)

OPERATION - HOSE CLAMPS
The spring type hose clamp applies constant ten-
sion on a hose connection. To remove a spring type
hose clamp, use Special Tool 6094 or equivalent, con-
stant tension clamp pliers (Fig. 24) to compress the
hose clamp.
RADIATOR FAN RELAY
DESCRIPTION
The low and high speed fan relays are mounted to
the upper radiator support above the charge air
cooler (Fig. 25).
OPERATION
The cooling system uses two fans. Both fans oper-
ate at two different speeds, low and high. Depending
on engine coolant temperature and A/C system high
side pressure, the fans operate at either low or high.
The ignition switch supplies voltage to the coil side of
the relay. When the ECM grounds the coil side of the
relay, the contacts close and the battery supplies
power to the fans.
COOLANT SYSTEM HOSES
REMOVAL - UPPER RADIATOR HOSE
WARNING: THE WARNING WORDS ªDO NOT OPEN
HOTº ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM
IS HOT OR UNDER PRESSURE.(1) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(2) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(3) Remove upper radiator hose (Fig. 26).
REMOVAL - LOWER RADIATOR HOSE
WARNING: THE WARNING WORDS ªDO NOT OPEN
HOTº ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM
IS HOT OR UNDER PRESSURE.
(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(2) Remove lower radiator hose (Fig. 26).
REMOVAL - COOLANT BYPASS HOSE
WARNING: THE WARNING WORDS ªDO NOT OPEN
HOTº ON THE RADIATOR PRESSURE CAP IS A
SAFETY PRECAUTION. WHEN HOT, PRESSURE
BUILDS UP IN COOLING SYSTEM. TO PREVENT
SCALDING OR INJURY, THE RADIATOR CAP
SHOULD NOT BE REMOVED WHILE THE SYSTEM
IS HOT OR UNDER PRESSURE.
(1) Drain cooling system (Refer to 7 - COOLING/
ENGINE/COOLANT - STANDARD PROCEDURE).
(2) Remove the coolant bypass hose (Fig. 26).
Fig. 24 Hose Clamp Tool
1 - HOSE CLAMP TOOL 6094
2 - HOSE CLAMP
Fig. 25 RELAY LOCATIONS
1 - GLOW PLUG RELAY
2 - UPPER RADIATOR SUPPORT
3 - CHARGE AIR COOLER OUTLET HOSE
4 - RADIATOR FAN RELAYS
5 - UPPER RADIATOR HOSE
6 - EGR SOLENOID
7a - 28 ENGINERG
HOSE CLAMPS (Continued)

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
ELECTRONIC CONTROL MODULES
STANDARD PROCEDURE...................1
PCM/SKIM PROGRAMMING................1
BODY CONTROL MODULE
DESCRIPTION............................2
OPERATION.............................3
REMOVAL...............................3
INSTALLATION............................3
CONTROLLER ANTILOCK BRAKE
DESCRIPTION............................3
OPERATION.............................3
REMOVAL...............................4
INSTALLATION............................4
DATA LINK CONNECTOR
DESCRIPTION............................5
OPERATION.............................5
FRONT CONTROL MODULE
DESCRIPTION............................5
OPERATION.............................5
DIAGNOSIS AND TESTING..................6
FRONT CONTROL MODULE...............6
REMOVAL...............................6
INSTALLATION............................6
MEMORY HEATED SEAT/MIRROR MODULE
REMOVAL...............................7
INSTALLATION............................7
POWER LIFTGATE MODULE
DESCRIPTION............................7
OPERATION.............................7REMOVAL...............................7
INSTALLATION............................8
POWERTRAIN CONTROL MODULE
DESCRIPTION............................8
OPERATION.............................19
STANDARD PROCEDURE..................21
OBTAINING DIAGNOSTIC TROUBLE
CODES...............................21
REMOVAL..............................22
INSTALLATION...........................22
SENTRY KEY IMMOBILIZER MODULE
DESCRIPTION...........................22
OPERATION.............................23
REMOVAL..............................23
INSTALLATION...........................23
SLIDING DOOR CONTROL MODULE
DESCRIPTION...........................23
OPERATION.............................24
REMOVAL..............................24
INSTALLATION...........................24
TRANSMISSION CONTROL MODULE
DESCRIPTION...........................24
OPERATION.............................24
STANDARD PROCEDURE..................27
PINION FACTOR PROCEDURE............27
QUICK LEARN PROCEDURE..............27
TCC BREAK-IN VIEW/RESET PROCEDURE. . . 28
REMOVAL..............................28
INSTALLATION...........................29
ELECTRONIC CONTROL
MODULES
STANDARD PROCEDURE - PCM/SKIM
PROGRAMMING
NOTE: Before replacing the PCM for a failed driver,
control circuit or ground circuit, be sure to check
the related component/circuit integrity for failures
not detected due to a double fault in the circuit.
Most PCM driver/control circuit failures are caused
by internal component failures (i.e. relay and sole-
noids) and shorted circuits (i.e. pull-ups, drivers
and switched circuits). These failures are difficult to
detect when a double fault has occurred and only
one DTC has set.When a PCM (SBEC) and the SKIM are replaced
at the same time perform the following steps in
order:
(1) Program the new PCM (SBEC)
(2) Program the new SKIM
(3) Replace all ignition keys and program them to
the new SKIM.
PROGRAMMING THE PCM (SBEC)
The SKIS Secret Key is an ID code that is unique
to each SKIM. This code is programmed and stored
in the SKIM, PCM and transponder chip (ignition
keys). When replacing the PCM it is necessary to
program the secret key into the new PCM using the
DRB III. Perform the following steps to program the
secret key into the PCM.
RSELECTRONIC CONTROL MODULES8E-1

OPERATION
The Body Control Module (BCM) is designed to
control and integrate many of the electronic features
and functions of the vehicle. The microprocessor-
based BCM hardware and software monitors many
hard wired switch and sensor inputs as well as those
resources it shares with other electronic modules in
the vehicle through its communication over the PCI
data bus network. The internal programming and all
of these inputs allow the BCM microprocessor to
determine the tasks it needs to perform and their
priorities, as well as both the standard and optional
features that it should provide. The BCM program-
ming then performs those tasks and provides those
features through both PCI data bus communication
with other electronic modules and through hard
wired low current outputs to a number of relays.
These relays provide the BCM with the ability to
control numerous high current accessory systems in
the vehicle.
The BCM monitors its own internal circuitry as
well as many of its input and output circuits, and
will store a Diagnostic Trouble Code (DTC) in elec-
tronic memory for any failure it detects. These DTCs
can be retrieved and diagnosed using a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove lower steering column cover and knee
blocker reinforcement.
(3) Disconnect two wire connectors from bottom of
Body Control Module (BCM)
(4) Remove bolts holding the BCM to the dash
panel mounting bracket.
(5) Remove the BCM from the mounting bracket.
INSTALLATION
(1) Install the BCM onto the mounting bracket.
(2) Install the bolts holding the BCM to dash
panel mounting bracket.
(3) Connect two wire connectors to the bottom of
the BCM.
(4) Install the lower steering column cover and
knee blocker reinforcement.
(5) Connect the battery negative cable.
CONTROLLER ANTILOCK
BRAKE
DESCRIPTION
The controller antilock brake (CAB) is a micropro-
cessor-based device which monitors the antilock
brake system (ABS) during normal braking and con-trols it when the vehicle is in an ABS stop. The CAB
is mounted to the HCU as part of the integrated con-
trol unit (ICU) (Fig. 1). The CAB uses a 24-way elec-
trical connector on the vehicle wiring harness. The
power source for the CAB is through the ignition
switch in the RUN or ON position. The CAB is on
the PCI bus.
OPERATION
The primary functions of the controller antilock
brake (CAB) are to:
²Monitor the antilock brake system for proper
operation.
²Detect wheel locking or wheel slipping tenden-
cies by monitoring the speed of all four wheels of the
vehicle.
²Control fluid modulation to the wheel brakes
while the system is in an ABS mode.
²Store diagnostic information.
²Provide communication to the DRBIIItscan tool
while in diagnostic mode.
²Illuminate the amber ABS warning indicator
lamp.
²(With traction control only) Illuminate the TRAC
ON lamp in the message center on the instrument
panel when a traction control event occurs.
²(with traction control only) Illuminate the TRAC
OFF lamp when the amber ABS warning indicator
lamp illuminates.
The CAB constantly monitors the antilock brake
system for proper operation. If the CAB detects a
fault, it will turn on the amber ABS warning indica-
tor lamp and disable the antilock braking system.
Fig. 1 INTEGRATED CONTROL UNIT (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
RSELECTRONIC CONTROL MODULES8E-3
BODY CONTROL MODULE (Continued)

(2) Reconnect the 24±way electrical and the pump/
motor connector. (Fig. 2)
(3) Install the battery tray (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - INSTALLATION).
(4) Install the screw securing the coolant filler
neck to the battery tray.
(5) Reconnect the vacuum hose to the coolant tank
built into the battery tray.
(6) Install the battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(7) Reconnect the battery cables.
(8) Connect a DRBIIItto the vehicle and initialize
the system.
DATA LINK CONNECTOR
DESCRIPTION
The data link connector is located inside the vehi-
cle, below instrument panel next to the center col-
umn (Fig. 4) .
OPERATION
The data link connector (diagnostic connector)
links the DRB scan tool with the Powertrain Control
Module (PCM). Refer to On-Board Diagnostics in the
General Diagnosis section of this group.
FRONT CONTROL MODULE
DESCRIPTION
The Front Control Module (FCM) is a micro con-
troller based module located in the engine compart-
ment (Fig. 5). This FCM mates to the power
distribution center to form the Intelligent PowerModule (IPM). The intelligent power module connects
directly to the battery and provides the primary
means of circuit protection and power distribution for
all vehicle electrical systems. The front control mod-
ule controls power to some of these vehicle systems
electrical and electromechanical loads based on
inputs received from hard wired switch inputs and
data received on the PCI bus circuit (J1850).
For information on theIntelligent Power Mod-
ule(IPM)Refer to the Power Distribution Sec-
tionof the service manual.
OPERATION
As messages are sent over the PCI bus circuit, the
front control module reads these messages and con-
trols power to some of the vehicles electrical systems
by completing the circuit to ground (low side driver)
or completing the circuit to 12 volt power (high side
driver). The following functions arecontrolledby
the Front Control Module:
²Occupant Restraint Controller Voltage
²Headlamp Power with Voltage Regulation
²Side Airbag Voltage
²Electronic Transaxle (Gasoline engine Vehicles)
²Brake Transmission Shift Interlock Functions
(BTSI)
²Front Windshield Wiper ªONº Relay Actuation
²Front Windshield Wiper ªHIº & ªLOº Relay
Actuation
²Front Washer Motor
²Rear Washer Motor
Fig. 4 DATA LINK CONNECTOR
Fig. 5 FRONT CONTROL MODULE
1 - FRONT CONTROL MODULE
RSELECTRONIC CONTROL MODULES8E-5
CONTROLLER ANTILOCK BRAKE (Continued)

²Front Fog Lamp Relay Actuation
²Front and Rear Blower Motor Relay Actuation
²Accessory Relay Actuation
²Electronic Back Light (EBL) Rear Defogger
²Horn Relay Actuation
²Park Lamp Relay Actuation
²Name Brand Speaker (NBS) Relay Actuation
²Headlamp Washer Relay Actuation
²Diesel Cabin Heater (Diesel Engine Vehicles)
The following inputs areReceived/Monitoredby
the Front Control Module:
²B+ Connection Detection
²Ambient Temperature Sensing
²Right/Left Park Lamp Outage
²Ignition Switch Start Only
²Ignition Switch Run and Start Only
²Washer Fluid Level
²Windshield Wiper Park
²Brake Fluid Level
²Back-Up switch
²Stop Lamp Sense
²Engine Crank Signal (Diesel Engine Vehicles)
²Horn Input
DIAGNOSIS AND TESTING - FRONT CONTROL
MODULE
The front control module is a printed circuit board
based module with a on-board micro-processor. The
front control module interfaces with other electronic
modules in the vehicle via the Programmable Com-
munications Interface (PCI) data bus (J1850). In
order to obtain conclusive testing the Programmable
Communications Interface (PCI) data bus network
and all of the electronic modules that provide inputs
to, or receive outputs from the front control module
must be checked. All PCI (J1850) communication
faults must be resolved prior to further diagnosing
any front control module related issues.
The front control module was designed to be diag-
nosed with an appropriate diagnostic scan tool, such
as the DRB IIIt. The most reliable, efficient, and
accurate means to diagnose the front control module
requires the use of a DRB IIItscan tool and the
proper Body Diagnostic Procedures manual.
Before any testing of the front control module is
attempted, the battery should be fully charged and
all wire harness and ground connections inspected
around the affected areas on the vehicle.
REMOVAL
(1) Disconnect the positive and negative battery
cables from the battery.
(2) Remove the battery from the vehicle. Refer to
the procedure in Battery Systems.(3) Using a long flat-pladed screwdriver, gently
twist the Intelligent Power Module (IPM) retaining
clip outboard to free the intelligent power module
from its mounting bracket (Fig. 6). Rotate intelligent
power module upward to access the Front Control
Module (FCM) retaining screws.
(4) Remove the front control module retaining
screws.
(5) Using both hands, pull the front control module
straight from the intelligent power module assembly
to disconnect the 49-way electrical connector (Fig. 7)
and remove the front control module from the vehi-
cle.
INSTALLATION
(1) Install the front control module in the intelli-
gent power module assembly by pushing the 49-way
electrical connector straight in (Fig. 7).
(2) Install the front control module retaining
screws. Torque the screws to 7 in. lbs.
(3) Rotate the intelligent power module assembly
downward to secure in mounting bracket.
(4) Install the battery in the vehicle. Refer to the
procedure in Battery Systems.
(5) Connect the positive and negative battery
cables.
NOTE: If the vehicle is not equipped with Name
Brand Speakers (NBS, Infinity) or Headlamp Wash-
ers the DRB IIITmust be used to Disable the appro-
priate relays in the Intelligent Power Module
Assembly.
Fig. 6 REMOVING INTELLIGENT POWER MODULE
8E - 6 ELECTRONIC CONTROL MODULESRS
FRONT CONTROL MODULE (Continued)