2002 CHRYSLER CARAVAN battery

ignition switch. This chime will operate for all igni-
tion positions except ON and START.
With the ignition switch in the OFF position
O N LY:
²Driver's door is open/ajar (door ajar switch is
closed to ground)
²Key is in the ignition switch (ignition is in the
LOCK position)
The chime will sound until one of the above condi-
tions is removed or until battery protection time out
(15 min.) has expired. Chime rate: 168 to 192 chimes
per minute.
To test the key-in ignition function, insert key into
the ignition and open drivers door. Do not turn igni-
tion ON. Chime should sound until key is removed
from ignition or drivers door is closed.
For diagnosis and testing of the Key-In chime for
other ignition positions, use the same testing proce-
dure as above but with the key in the accessory or
unlock position.
DIAGNOSIS AND TESTING - LOW OIL
PRESSURE CHIME
The low oil pressure chime will warn the driver
that the engine oil pressure is low. The oil pressure
switch will close to ground during a low oil pressure
condition. The oil pressure lamp will illuminate in
the message center. The PCM will monitor the oil
pressure switch and signal a low oil pressure condi-
tion. A continuous four minute warning chime will
sound and the oil pressure lamp will come ON when
the following conditions are met:
²Ignition on and engine not cranking
²Engine running at 420 to 480 rpm for 10 sec-
onds
²Oil pressure switch closed to ground for (1 sec-
ond minimum, 2 seconds maximum)
Chime rate: 168 to 192 chimes per minute.
DIAGNOSIS AND TESTING - SEAT BELT CHIME
The seat belt chime will sound for 4 to 8 seconds,
when the ignition is turned on and the driver's seat
belt is not buckled (seat belt switch is closed to
ground). This is a reminder to the driver to buckle
the seat belt. The seat belt lamp is controlled by the
ORC. The cluster will also bulb check the seat belt
warning lamp for 6 seconds. Buckling the driver's
seat belt before the time out has expired will cause
the chime to stop immediately. Chime rate: 38 to 62
chimes per minute but the lamp will remain on until
6 seconds have expired.
To test the seat belt warning system, the ignition
switch must be in the OFF position for 1 minute
before starting the test. Turn the ignition switch to
the on position with the driver's seat belt not buck-led. The seat belt warning lamp should light and the
chime should sound 4 to 8 seconds.
DIAGNOSIS AND TESTING - SEAT BELT LAMP
The seat belt lamp in the instrument cluster sig-
nals the vehicle passengers to fasten their seat belts.
The seat belt lamp is illuminated directly by the
instrument cluster for 6 seconds after the instrument
cluster receives the message from the ORC. The seat
belt lamp is therefore illuminated for 6 seconds
whenever the ignition switch is moved to run/start
position.
(1) While ignition is off, the seat belt lamp will not
be illuminated.
(2) The ignition power feed status will be updated
every 250 milliseconds or on change.
(3) This lamp will be checked by the instrument
cluster for 6 seconds with every run/start cycle of the
ignition switch.
DIAGNOSIS AND TESTING - TIRE PRESSURE
MONITOR
The Tire Pressure Warning chime, as well as the
information being displayed in the EVIC, will act as
a warning to the driver that a tire has either Low or
High pressure, or if there is a need to service the
Tire Pressure Monitor System. With the ignition
switch in the ON position and the ªLow Pressure/
High Pressureº or ªService the TPM Systemº dis-
played on the EVIC display, a single chime will
sound.
DIAGNOSIS AND TESTING - TURN SIGNAL ON
CHIME
The turn signal on chime will warn the driver that
the turn signals have been left on. When the body
control module receives a turn signal input for 1.0
mile, vehicle speed is greater than 24 km/h (15 mph),
the chime will sound continuously until the turn sig-
nal is turned OFF. If vehicle speed drops below 24
km/h (15 mph) prior to the warning being activated,
the accumulated distance traveled will be reset. The
turn signal chime is not activated when the emer-
gency flashers are turned on. Chime rate: 50   12
chimes per minute.
For the turn signal warning system to operate:
²Must have input from either the right or left
turn signal lamps. Creates a voltage change between
0 and battery voltage.
²The vehicle speed sensor sends a message to the
Powertrain Control Module that vehicle has exceeded
24 km/h (15 mph) for 1.0 mile).
²When the above two conditions are met, the
chime will sound. The chime will stop when no fur-
ther voltage change is detected.
RSCHIME/BUZZER8B-3
CHIME/BUZZER (Continued)
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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.
(1) Turn the ignition switch on (transmission in
park/neutral).
(2) Use the DRB III and select THEFT ALARM,
SKIM then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE).
(4) Enter secured access mode by entering the
vehicle four-digit PIN.
(5) Select ENTER to update PCM VIN.
NOTE: If three attempts are made to enter secure
access mode using an incorrect PIN, secured
access mode will be locked out for one hour. To
exit this lockout mode, turn the ignition to the RUN
position for one hour then enter the correct PIN.
(Ensure all accessories are turned off. Also monitor
the battery state and connect a battery charger if
necessary).
(6) Press ENTER to transfer the secret key (the
SKIM will send the secret key to the PCM).
(7) Press Page Back to get to the Select System
menu and select ENGINE, MISCELLANEOUS, and
SRI MEMORY CHECK.(8) The DRB III will ask, Is odometer reading
between XX and XX? Select the YES or NO button on
the DRB III. If NO is selected, the DRB III will read,
Enter odometer Reading. Enter
the odometer reading from the Instrument Panel and
press ENTER.
PROGRAMMING THE SKIM
(1) Turn the ignition switch on (transmission in
park/neutral).
(2) Use the DRB III and select THEFT ALARM,
SKIM then MISCELLANEOUS.
(3) Select PCM REPLACED (GAS ENGINE).
(4) Program the vehicle four-digit PIN into SKIM.
(5) Select COUNTRY CODE and enter the correct
country.
NOTE: Be sure to enter the correct country code. If
the incorrect country code is programmed into
SKIM, the SKIM must be replaced.
(6) Select YES to update VIN (the SKIM will learn
the VIN from the PCM).
(7) Press ENTER to transfer the secret key (the
PCM will send the secret key to the SKIM).
(8) Program ignition keys to SKIM.
NOTE: If the PCM and the SKIM are replaced at the
same time, all vehicle keys will need to be replaced
and programmed to the new SKIM.
PROGRAMMING IGNITION KEYS TO THE SKIM
(1) Turn the ignition switch on (transmission in
park/neutral).
(2) Use the DRB III and select THEFT ALARM,
SKIM then MISCELLANEOUS.
(3) Select PROGRAM IGNITION KEY'S.
(4) Enter secured access mode by entering the
vehicle four-digit PIN.
NOTE: A maximum of eight keys can be learned to
each SKIM. Once a key is learned to a SKIM it (the
key) cannot be transferred to another vehicle.
If ignition key programming is unsuccessful, the
DRB III will display one of the following messages:
Programming Not Attempted - The DRB III
attempts to read the programmed key status and
there are no keys programmed into SKIM memory.
Programming Key Failed (Possible Used Key From
Wrong Vehicle) - SKIM is unable to program key due
to one of the following:
²faulty ignition key transponder
²ignition key is programmed to another vehicle.
8 Keys Already Learned, Programming Not Done -
SKIM transponder ID memory is full.
8E - 2 ELECTRONIC CONTROL MODULESRS
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(5) Obtain ignition keys to be programmed from
customer (8 keys maximum).
(6) Using the DRB III, erase all ignition keys by
selecting MISCELLANEOUS and ERASE ALL CUR-
RENT IGN. KEYS.
(7) Program all ignition keys.
Learned Key In Ignition - Ignition key transponder
ID is currently programmed in SKIM memory.
ADJUSTABLE PEDAL MODULE
DIAGNOSIS AND TESTING - ADJUSTABLE
PEDAL MODULE
Refer to Appropriate Diagnostic Information.
REMOVAL
(1) Remove adjustable pedal assembly from vehi-
cle. (Refer to 5 - BRAKES/HYDRAULIC/MECHANI-
CAL/PEDAL - REMOVAL)
(2) Disconnect 2 wiring connectors from module
(Fig. 1).
(3) Remove cable from routing clips on module
(Fig. 1).
(4) Remove module mounting screws.
(5) Remove module.
INSTALLATION
(1) Install module on pedal assembly and install
mounting screws.
(2) Place cable in routing clips on module (Fig. 1).
(3) Connect 2 wiring connectors to module (Fig. 1).(4) Install adjustable pedal assembly. (Refer to 5 -
BRAKES/HYDRAULIC/MECHANICAL/PEDAL -
INSTALLATION)
BODY CONTROL MODULE
DESCRIPTION
The Body Control Module (BCM) is located in the
passenger compartment, attached to the bulkhead
underneath the left side of the instrument panel.
The BCM utilizes integrated circuitry and informa-
tion carried on the Programmable Communications
Interface (PCI) data bus network along with many
hard wired inputs to monitor many sensor and
switch inputs throughout the vehicle. In response to
those inputs, the internal circuitry and programming
of the BCM allow it to control and integrate many
electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus.
OPERATION
The Body Control Module (BCM) supplies vehicle
occupants with visual and audible information and
controls various vehicle functions. To provide and
receive information, the BCM is interfaced to the
vehicle's serial bus communications network, referred
to as the Programmable Communications Interface
(PCI) bus.
This network consists of the;
²Powertrain Control Module (PCM)
²Transmission Control Module (TCM)
²Mechanical Instrument Cluster (MIC)
²Occupant Restraint Controller (ORC)
²Compass/Mini-Trip Computer (CMTC)
²Electronic Vehicle Information Center (EVIC)
²Controller Antilock Brake (CAB)
²HVAC Control Module
²Sliding Door Control Modules (driver and pas-
senger side doors)
²Power Liftgate Module (PLG)
²Audio system equipped with RAZ, RBU, RBK,
and RBB radios.
²Side Impact Airbag Control Module (SIACM)
²Memory Seat Module (MSM)
²Sentry Key Immobilizer Module (SKIM)
The BCM is operational when battery power is
supplied to the module.
The BCM provides the following features:
²Power Door Locks
²Automatic Door Locks
²Battery Protection - The BCM will automatically
turn off all exterior lamps after 3 minutes, and all
Fig. 1 Adjustable Pedal Module
1 - CABLE
2 - ADJUSTABLE PEDAL MODULE
3 - WIRING CONNECTORS
4 - ADJUSTABLE PEDAL ASSEMBLY
RSELECTRONIC CONTROL MODULES8E-3
ELECTRONIC CONTROL MODULES (Continued)
ProCarManuals.com

When replacing a BCM there are three modules
available:
²Base
²Midline
²Highline
The Midline controller is used on vehicles that
have Power Door Locks and the Highline controller is
used for vehicles equipped with a Power Liftgate. If a
vehicle is equipped with the Vehicle Theft Security
System, the Midline/Highline controller becomes a
Premium when the theft feature is enabled.
CAUTION: Do not swap Body Control Modules
between vehicles or body controller's off the shelf.
The BCM has internal diagnostic capability that
assists in diagnosing the system error. When an
OPEN or a SHORT circuit exists, the diagnostic tool
can be used to read the BCM faults. The faults are
very descriptive in identifying the appropriate fea-
ture that has faulted.
The only two faults that the BCM logs that con-
clude the replacement of a BCM are faults;
²# 01 - Internal BCM failure (replace BCM)
²# 1F - J1850 Internal Hardware Failure (replace
BCM)
Otherwise the appropriate diagnostic procedures
for each of the features should be taken when the
BCM logs a fault.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the lower instrument panel silencer.
(3) Remove the knee blocker and reinforcement
(Refer to 23 - BODY/INSTRUMENT PANEL/KNEE
BLOCKER REINFORCEMENT - REMOVAL).
(4) Disconnect the five wire connectors from the
bottom of the Body Control Module (BCM).
(5) Move bulkhead wiring aside.
(6) Remove the screws holding the BCM to the
bulkhead.
(7) Remove the BCM from the mounting bracket.
INSTALLATION
(1) Install the BCM to the mounting bracket.
(2) Install the screws holding the BCM to the
bulkhead.
(3) Connect the five wire connectors to the bottom
of the Body Control Module (BCM).
(4) Install the knee blocker and reinforcement
(Refer to 23 - BODY/INSTRUMENT PANEL/KNEE
BLOCKER REINFORCEMENT - INSTALLATION).
(5) Install the lower instrument panel silencer.
(6) Connect the battery negative cable.
(7) Verify proper operation of BCM and its func-
tions.
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. 2). 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.
Fig. 2 Integrated Control Unit (ICU)
1 - PUMP/MOTOR
2 - HCU
3 - PUMP/MOTOR CONNECTOR
4 - CAB
RSELECTRONIC CONTROL MODULES8E-5
BODY CONTROL MODULE (Continued)
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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.
The normal base braking system will remain opera-
tional.
NOTE: If the vehicle is equipped with traction con-
trol, the TRAC OFF lamp will illuminate anytime the
amber ABS warning indicator lamp illuminates.
The CAB continuously monitors the speed of each
wheel through the signals generated by the wheel
speed sensors to determine if any wheel is beginning
to lock. When a wheel locking tendency is detected,
the CAB commands the CAB command coils to actu-
ate. The coils then open and close the valves in the
HCU that modulate brake fluid pressure in some or
all of the hydraulic circuits. The CAB continues to
control pressure in individual hydraulic circuits until
a locking tendency is no longer present.
The CAB contains a self-diagnostic program that
monitors the antilock brake system for system faults.
When a fault is detected, the amber ABS warning
indicator lamp is turned on and the fault diagnostic
trouble code (DTC) is then stored in a diagnostic pro-
gram memory. These DTC's will remain in the CAB
memory even after the ignition has been turned off.
The DTC's can be read and cleared from the CAB
memory by a technician using the DRBIIItscan tool.
If not cleared with a DRBIIItscan tool, the fault
occurrence and DTC will be automatically cleared
from the CAB memory after the identical fault has
not been seen during the next 3,500 miles.
CAB INPUTS
²Wheel speed sensors (four)
²Brake lamp switch
²Ignition switch
²System and pump voltage
²Ground
²Traction control switch (if equipped)
²Diagnostic communication (PCI)
CAB OUTPUTS
²Amber ABS warning indicator lamp actuation
(via BUS)
²Instrument cluster (MIC) communication (PCI)
²Traction control lamps (if equipped)
²Diagnostic communication (PCI, via BUS)
REMOVAL
(1) Disconnect the battery cables.(2) Remove the battery (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/BATTERY - REMOVAL).
(3) Disconnect the vacuum hose connector at the
tank built into the battery tray.
(4) Remove the screw securing the coolant filler
neck to the battery tray.
(5) Remove the battery tray (Refer to 8 - ELEC-
TRICAL/BATTERY SYSTEM/TRAY - REMOVAL).
(6) Pull up on the CAB connector lock and discon-
nect the 24±way electrical connector (Fig. 3).
(7) Disconnect the pump/motor connector from the
CAB.
(8) Remove the screws securing the CAB to the
HCU (Fig. 4)
(9) Pull CAB straight forward off HCU.
INSTALLATION
(1) Slide the CAB onto the HCU (Fig. 4).
(2) Install screws securing the CAB to the HCU
(Fig. 4) Tighten the mounting screws to 2 N´m (17 in
lbs).
(3) Reconnect the 24±way wiring connector and
the pump/motor wiring connector. (Fig. 3)
(4) Install the battery tray (Refer to 8 - ELECTRI-
CAL/BATTERY SYSTEM/TRAY - INSTALLATION).
(5) Install the screw securing the coolant filler
neck to the battery tray.
(6) Reconnect the vacuum hose to the coolant tank
built into the battery tray.
(7) Install the battery (Refer to 8 - ELECTRICAL/
BATTERY SYSTEM/BATTERY - INSTALLATION).
(8) Reconnect the battery cables.
Fig. 3 CAB Connector Lock
1 - CONNECTOR LOCK
2 - CAB
8E - 6 ELECTRONIC CONTROL MODULESRS
CONTROLLER ANTILOCK BRAKE (Continued)
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(9) 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. 5).
OPERATION
The data link connector (diagnostic connector)
links the DRB scan tool with the Powertrain ControlModule (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. This FCM mates to the power distribution
center to form the Integrated Power Module (IPM).
The IPM connects directly to the battery and pro-
vides the primary means of circuit protection and
power distribution for all vehicle electrical systems.
The FCM controls power to some of these vehicle sys-
tems electrical and electromechanical loads based on
inputs received from hard wired switch inputs and
data received on the Programmable Communications
Interface (PCI) data bus.
For information on the IPM, (Refer to 8 - ELEC-
TRICAL/POWER DISTRIBUTION/INTEGRATED
POWER MODULE - DESCRIPTION)
OPERATION
As messages are sent over the Programmable Com-
munications Interface (PCI) data bus, the Front Con-
trol Module (FCM) reads these messages and controls
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:
²Accessory Relay Actuation
²Brake Transmission Shift Interlock Functions
(BTSI)
²Diesel Cabin Heater (Diesel Engine Vehicles)
²Electronic Back Light (EBL) Rear Defogger
²Electronic Transaxle (Gasoline engine Vehicles)
²Front and Rear Blower Motor Relay Actuation
²Front Fog Lamp Relay Actuation
²Front Washer Motor
²Front Windshield Wiper ªHIº & ªLOº Relay
Actuation
²Front Windshield Wiper ªONº Relay Actuation
²Headlamp Power with Voltage Regulation
²Horn Relay Actuation
²Headlamp Washer Relay Actuation
²Name Brand Speaker (NBS) Relay Actuation
²Occupant Restraint Controller Voltage
²Park Lamp Relay Actuation
²Rear Washer Motor
²Side Airbag Voltage
The following inputs areReceived/Monitoredby
the Front Control Module:
²Ambient Temperature Sensing
Fig. 4 CAB Mounting Screws
1 - HCU
2 - MOUNTING SCREWS
3 - CAB
Fig. 5 DATA LINK CONNECTOR
RSELECTRONIC CONTROL MODULES8E-7
CONTROLLER ANTILOCK BRAKE (Continued)
ProCarManuals.com

²Back-Up switch
²Brake Fluid Level
²B+ Connection Detection
²Engine Crank Signal (Diesel Engine Vehicles)
²Horn Input
²Ignition Switch Start Only
²Ignition Switch Run and Start Only
²Stop Lamp Sense
²Washer Fluid Level
²Windshield Wiper Park
DIAGNOSIS AND TESTING - FRONT CONTROL
MODULE
The Front Control Module (FCM) is a printed cir-
cuit board based module with a on-board micro-pro-
cessor. The FCM interfaces with other electronic
modules in the vehicle via the Programmable Com-
munications Interface (PCI) data bus. In order to
obtain conclusive testing the PCI data bus and all of
the electronic modules that provide inputs to, or
receive outputs from the FCM must be checked. All
PCI communication faults must be resolved prior to
further diagnosing any front control module related
issues.
The FCM was designed to be diagnosed 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 Diag-
nostic Procedures manual.
Before any testing of the FCM 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-bladed screwdriver, gently
twist the Integrated Power Module (IPM) retaining
clip outboard to free the IPM from its mounting
bracket (Fig. 6). Rotate IPM upward to access the
Front Control Module (FCM) retaining screws.
(4) Remove the front control module retaining
screws.
(5) Using both hands, pull the FCM straight from
the IPM assembly to disconnect the 49-way electrical
connector (Fig. 7) and remove the front control mod-
ule from the vehicle.
INSTALLATION
NOTE: Front Control Module must be programmed
to the correct radio EQ curve using the DRB IIIT.This will ensure that the audio system is operating
correctly.
(1) Install the Front Control Module (FCM) in the
Integrated Power Module (IPM) assembly by pushing
the 49-way electrical connector straight in.
(2) Install the FCM retaining screws. Torque the
screws to 1 N´m (7 in. lbs).
(3) Rotate the IPM assembly downward to secure
in mounting bracket.
Fig. 6 REMOVING INTELLIGENT POWER MODULE
Fig. 7 FRONT CONTROL MODULE
1 - FRONT CONTROL MODULE
8E - 8 ELECTRONIC CONTROL MODULESRS
FRONT CONTROL MODULE (Continued)
ProCarManuals.com

(4) Install the battery in the vehicle. Refer to the
procedure in Battery Systems.
(5) Connect the positive and negative battery
cables.
(6) Using the DRB IIIt, under ªFRONT CON-
TROL MODULEº then ªMISCº program the EQ
curve of the radio into the Front Control Module.
Refer to the appropriate diagnostic manual.
NOTE: If the vehicle is not equipped with Name
Brand Speakers (Infinity, etc.) or Headlamp Washers
the DRB IIITmust be used to Disable the appropri-
ate relays in the Intelligent Power Module Assembly.
HEATED SEAT MODULE
DESCRIPTION
Vehicles equipped with heated seats utilize two
heated seat modules. The heated seat modules (Fig.
8) are located under the front seats, where they are
secured to the seat cushion pans. The left heated
seat module controls the left heated seat, and the
right controls the right. Each heated seat module has
three connector receptacles that allows the module to
be connected to all of the required inputs and out-
puts through the seat wire harness.The heated seat module is an electronic micropro-
cessor controlled device designed and programmed to
use inputs from the ignition switch, heated seat
switch and the heated seat sensor to operate and
control the heated seat elements in the front seat
and the two heated seat indicator lamp Light-Emit-
ting Diodes (LEDs) in the heated seat switch.
The heated seat module cannot be repaired. If the
heated seat module is damaged or faulty, the entire
module must be replaced.
OPERATION
The heated seat module operates on fused battery
current received from the ignition switch and inte-
grated power module. The module is grounded at all
times through the seat wire harness. Inputs to the
module include a resistor multiplexed heated seat
switch request circuit for the heated seat switch and
the heated seat sensor inputs from the seat cushions
of each front seat. In response to those inputs the
heated seat module controls battery current feeds to
the heated seat elements, and controls the ground for
the heated seat switch indicator lamps.
When a heated seat switch request signal is
received by the heated seat module, the module ener-
gizes the proper indicator lamp (Low or High) in the
switch by grounding the indicator lamp circuit to
indicate that the heated seat system is operating. At
the same time, the heated seat module energizes the
selected heated seat sensor circuit and the sensor
provides the module with an input indicating the
surface temperature of the selected seat cushion.
The Low heat set point is about 38É C (100.4É F),
and the High heat set point is about 42É C (107.6É F).
If the seat cushion surface temperature input is
below the temperature set point for the selected tem-
perature setting, the heated seat module energizes
an N-channel Field Effect Transistor (N-FET) within
the module which energizes the heated seat elements
in the selected seat cushion and back. When the sen-
sor input to the module indicates the correct temper-
ature set point has been achieved, the module
de-energizes the N-FET which de-energizes the
heated seat elements. The heated seat module will
continue to cycle the N-FET as needed to maintain
the selected temperature set point.
DIAGNOSIS AND TESTING - HEATED SEAT
MODULE
If a heated seat fails to heat and one or both of the
indicator lamps on a heated seat switch flash, refer
toDiagnosis and Testing Heated Seat Systemin
Heated Seats for the location of flashing LED heated
seat system diagnosis and testing procedures. If a
heated seat heats but one or both indicator lamps on
the heated seat switch fail to operate, test the heated
Fig. 8 RS/RG Heated Seat Modules
1 - HEATED SEAT MODULE
2 - C1 CONNECTOR
3 - C3 CONNECTOR
4 - C1 CONNECTOR
RSELECTRONIC CONTROL MODULES8E-9
FRONT CONTROL MODULE (Continued)
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