02 sensor wiring diagram JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

AUDIO
TABLE OF CONTENTS
page page
AUDIO
DESCRIPTION..........................1
OPERATION............................1
DIAGNOSIS AND TESTING - AUDIO..........2
AMPLIFIER CHOKE AND RELAY
DESCRIPTION..........................3
OPERATION............................3
DIAGNOSIS AND TESTING - AMPLIFIER
CHOKE AND RELAY....................4
REMOVAL.............................4
INSTALLATION..........................4
ANTENNA BODY & CABLE
DESCRIPTION..........................4
OPERATION............................5
DIAGNOSIS AND TESTING - ANTENNA BODY
AND CABLE..........................5
REMOVAL.............................6
INSTALLATION..........................6
CD CHANGER
DESCRIPTION..........................7
OPERATION............................7
REMOVAL.............................7
INSTALLATION..........................7
INSTRUMENT PANEL ANTENNA CABLE
REMOVAL.............................7INSTALLATION..........................8
RADIO
DESCRIPTION..........................8
OPERATION............................8
REMOVAL.............................9
INSTALLATION..........................9
RADIO NOISE SUPPRESSION GROUND STRAP
DESCRIPTION..........................9
OPERATION...........................10
REMOVAL.............................10
INSTALLATION.........................11
REMOTE SWITCHES
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - REMOTE
SWITCHES..........................12
REMOVAL.............................13
INSTALLATION.........................13
SPEAKER
DESCRIPTION.........................13
OPERATION...........................14
REMOVAL.............................14
INSTALLATION.........................15
AUDIO
DESCRIPTION
An audio system is standard factory-installed
equipment on this model. Several combinations of
radio receivers and speaker systems are offered on
this model. The audio system uses an ignition
switched source of battery current so that the system
will only operate when the ignition switch is in the
RUN or ACCESSORY positions.
The audio system includes the following compo-
nents:
²Amplifier choke and relay
²Antenna
²Compact disc changer (if equipped)
²Power amplifier mounted to each front door
speaker (with premium speaker system only)
²Radio noise suppression components
²Radio receiver
²Remote radio switches (if equipped)
²SpeakersCertain functions and features of the audio system
rely upon resources shared with other electronic
modules in the vehicle over the Programmable Com-
munication Interface (PCI) bus network. The data
bus network allows the sharing of sensor informa-
tion. For diagnosis of these electronic modules or of
the data bus network, the use of a DRB scan tool and
the proper Diagnostic Procedures manual are recom-
mended.
Refer to the appropriate wiring information for
complete standard and premium audio system circuit
diagrams. The wiring information includes proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices, and grounds.
OPERATION
The audio system components are designed to pro-
vide audio entertainment and information through
the reception, tuning and amplification of locally
broadcast radio signals in both the Amplitude Modu-
KJAUDIO 8A - 1

A chime warning system is standard factory-in-
stalled equipment on this model. The chime warning
system uses a single chime tone generator that is sol-
dered onto the electronic circuit board that is integral
to the ElectroMechanical Instrument Cluster (EMIC)
to provide an audible indication of various vehicle
conditions that may require the attention of the vehi-
cle operator or occupants (Fig. 1). The microproces-
sor-based EMIC utilizes electronic chime request
messages received from other electronic modules in
the vehicle over the Programmable Communications
Interface (PCI) data bus network along with hard
wired inputs to the cluster microprocessor to monitor
many sensors and switches throughout the vehicle.
In response to those inputs, the integrated circuitry
and internal programming of the EMIC allow it to
control audible outputs that are produced through its
on-board chime tone generator.
The EMIC circuitry and its chime tone generator
are capable of producing each of the four following
audible outputs:
²Fixed Duration Beep- A short, sharp, single
tactile ªbeep-likeº tone that is about 150 milliseconds
in duration.
²Single Chime Tone- A single ªbong-likeº chime
tone.
²Slow Rate Repetitive Chime- Repeated
chime tones that are issued at a slow rate of about
50 ªbong-likeº tones per minute.
²Fast Rate Repetitive Chime- Repeated chime
tones that are issued at a fast rate of about 180
ªbong-likeº tones per minute.
Hard wired circuitry connects the EMIC and the
various chime warning system switch and sensor
inputs to their electronic modules and to each other
through the electrical system of the vehicle. These
hard wired circuits are integral to numerous wire
harnesses, which are routed throughout the vehicle
and retained by many different methods. These cir-
cuits may be connected to each other, to the vehicle
electrical system and to the chime warning system
through the use of a combination of soldered splices,
splice block connectors, and many different types of
wire harness terminal connectors and insulators.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
The EMIC chime warning system circuitry and
integral chime tone generator cannot be adjusted or
repaired. If the EMIC or the chime tone generator
are damaged or faulty, the EMIC unit must be
replaced.OPERATION
The chime warning system is designed to provide
an audible output as an indication of various condi-
tions that may require the attention or awareness of
the vehicle operator or occupants. The chime warning
system components operate on battery current
received through a fused B(+) fuse in the Junction
Block (JB) on a non-switched fused B(+) circuit so
that the system may operate regardless of the igni-
tion switch position. However, the chime warning
system also monitors the ignition switch position so
that some chime features will only occur with igni-
tion switch in the On position, while others occur
regardless of the ignition switch position.
The chime warning system provides an audible
indication to the vehicle operator or occupants under
the following conditions:
²Airbag Indicator Warning- The ElectroMe-
chanical Instrument Cluster (EMIC) chime tone gen-
erator will generate one, short, ªbong-likeº chime
tone when the ignition switch is in the On position,
and an electronic message is received over the Pro-
grammable Communications Interface (PCI) data bus
from the Airbag Control Module (ACM) requesting
ªAirbagº indicator illumination. This warning will
only occur following completion of the ªAirbagº indi-
cator bulb test, and will only occur once during an
ignition cycle. The ACM uses internal programming,
hard wired inputs from the front Supplemental
Restraint System (SRS) components and, on vehicles
so equipped, electronic messages received over the
PCI data bus from each Side Impact Airbag Control
Module (SIACM) to determine the proper ªAirbagº
indicator messages to send to the EMIC.
²Anti-Lock Brake Indicator Warning- The
EMIC chime tone generator will generate one, short,
ªbong-likeº chime tone when the ignition switch is in
the On position, and an electronic message is
received over the PCI data bus from the Controller
Anti-lock Brake (CAB) requesting ªAntilock Brake
System (ABS)º indicator illumination. This warning
will only occur following completion of the ªABSº
indicator bulb test, and will only occur once during
an ignition cycle. The CAB uses internal program-
ming, hard wired inputs from the Antilock Brake
System (ABS) components, and electronic messages
received over the PCI data bus from the Powertrain
Control Module (PCM) to determine the proper
ªABSº indicator messages to send to the EMIC.
²Compass Mini-Trip Computer Reset- The
EMIC chime tone generator will generate one, short,
fixed duration ªbeep-likeº chime tone when the igni-
tion switch is in the On position, and an electronic
message is received over the PCI data bus from the
optional Compass Mini-Trip Computer (CMTC)
requesting that the CMTC elapsed time, average fuel
8B - 2 CHIME/BUZZERKJ
CHIME WARNING SYSTEM (Continued)

flip-up glass ajar switch, the hood ajar switch (in
required markets only), and the Remote Keyless
Entry (RKE) module to control the features of the
optional Vehicle Theft Security System (VTSS).
Hard wired circuitry connects the BCM to the elec-
trical system of the vehicle. These hard wired circuits
are integral to several wire harnesses, which are
routed throughout the vehicle and retained by many
different methods. These circuits may be connected to
each other, to the vehicle electrical system and to the
BCM through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
Many of the electronic features in the vehicle con-
trolled or supported by the BCM are programmable
using a customer programming procedure or the
DRBIIItscan tool. In addition, the BCM software is
Flash compatible, which means it can be repro-
grammed using Flash reprogramming procedures.
However, if any of the BCM hardware components is
damaged or faulty, the entire BCM unit must be
replaced.
OPERATION
The microprocessor-based Body Control Module
(BCM) monitors many hard wired switch and sensor
inputs as well as those resources it shares with other
electronic modules in the vehicle through its commu-
nication over the Programmable Communications
Interface (PCI) data bus network. The internal pro-
gramming 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 stan-
dard and optional features that it should provide.
The BCM programming then performs those tasks
and provides those features through both PCI data
bus communication with other electronic modules
and through hard wired outputs through a number of
driver circuits, relays, and actuators. These outputs
allow the BCM the ability to control numerous acces-
sory systems in the vehicle.
The BCM operates on battery current received
through a fuse in the Junction Block (JB) on a non-
switched fused B(+) circuit, through another fuse in
the JB on a fused ignition switch output (run-start)
circuit, and through a third fuse in the JB on a fused
ignition switch output (run-acc) circuit. This arrange-
ment allows the BCM to provide some features
regardless of the ignition switch position, while other
features will operate only with the ignition switch inthe On, Start, and/or Accessory positions. All of the
battery current circuits are connected to the BCM
through the JB/BCM connector. The BCM receives
ground through five separate circuits. Three of these
circuits are connected to the BCM through a connec-
tor and take out of the instrument panel wire har-
ness on three separate ground circuits, while the
other two circuits are connected to the BCM through
the JB/BCM connector. All of these circuits are
grounded through a splice block located in the instru-
ment panel wire harness with an eyelet terminal con-
nector that is secured by a nut to a ground stud on
the driver side instrument panel end bracket near
the JB.
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.
HARD WIRED INPUTS The hard wired inputs to
the BCM include the following:
²A/C on/off control
²Ambient temperature sensor signal
²Body control module flash enable
²Door lock switch mux
²Driver door ajar switch sense
²Flip-up glass ajar switch sense
²Flip-up glass release switch sense
²Fog lamp switch sense
²Front wiper park switch sense
²Front wiper switch mux
²Front washer pump driver
²Fused B(+)
²Fused ignition switch output (run-acc)
²Fused ignition switch output (run-start)
²Headlamp switch mux
²High beam switch sense
²Hood ajar switch sense - premium with
VTSS - in markets where required only
²Key-in ignition switch sense
²Left cylinder lock switch sense - premium
with VTSS only - omitted in some markets as
required
²Panel lamps dimmer switch mux
²Passenger doors ajar switch sense (input
from three ajar switches connected in parallel)
²Radio control mux - premium with remote
radio switches only
²Rear courtesy lamp control
²Rear window defogger control
²Rear wiper intermittent driver
²Rear wiper on driver
²Right cylinder lock switch sense - premium
with VTSS only - omitted in some markets as
required
KJELECTRONIC CONTROL MODULES 8E - 5
BODY CONTROL MODULE (Continued)

²Vacuum Fluorescent Display Synchroniza-
tion (CMTC, EMIC, Radio)
²Vehicle Theft Security System Status (PCM,
ITM) - premium only
Refer to the appropriate diagnostic information for
additional details.
DIAGNOSIS AND TESTING - BODY CONTROL
MODULE
The hard wired inputs to and outputs from the
Body Control Module (BCM), as well as other hard
wired circuits for this module may be diagnosed and
tested using conventional diagnostic tools and proce-
dures. However, conventional diagnostic methods
may not prove conclusive in the diagnosis of the
BCM, the Programmable Communications Interface
(PCI) data bus network, or the electronic messages
received and transmitted by the BCM over the PCI
data bus. The most reliable, efficient, and accurate
means to diagnose the BCM and the PCI data bus
network inputs to and outputs from this module
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
NOTE: Before replacing a Body Control Module
(BCM), use a DRBIIITscan tool to retrieve the cur-
rent settings for the BCM programmable features
and the axle ratio/tire size (electronic pinion factor).
Refer to the appropriate diagnostic information.
These settings should be duplicated in the replace-
ment BCM using the DRBIIITscan tool before
returning the vehicle to service.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Junction Block Module (JBM) from
the instrument panel end bracket on the driver side
of the vehicle. (Refer to 8 - ELECTRICAL/POWER
DISTRIBUTION/JUNCTION BLOCK - REMOVAL).
(3) Remove the four screws that secure the BCM
to the Junction Block (JB) (Fig. 3).
(4) Remove the BCM from the JB.
(5) If the vehicle is equipped with the optional
Remote Keyless Entry (RKE) system, remove the
RKE module from the receptacle on the BCM. (Refer
to 8 - ELECTRICAL/POWER LOCKS/REMOTE KEY-
LESS ENTRY MODULE - REMOVAL).
INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
KJELECTRONIC CONTROL MODULES 8E - 7
BODY CONTROL MODULE (Continued)

controls the ground for the heated seat switch indi-
cator lamps (LED's).
When a heated seat switch (Driver or Passenger) is
depressed a signal is received by the heated seat
module, the module energizes the proper indicator
LED (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 36É C (96.8É 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.
If the heated seat module detects a heated seat
sensor value input that is out of range or a shorted
or open heated seat element circuit, it will notify the
vehicle operator or the repair technician of this con-
dition by flashing the High and/or Low indicator
lamps in the affected heated seat switch. Refer to
Diagnosis and Testing Heated Seat Systemin
Heated Systems for flashing LED diagnosis and test-
ing procedures. Refer toDiagnosis and Testing
Heated Seat Modulein this section for heated seat
module diagnosis and testing procedures. Also refer
to the Body Diagnostic Manual for additional diagno-
sis and testing procedures.
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
toHeated Seat System Diagnosis and Testingin
Heated Systems for flashing LED failure identifica-
tion. Refer toWiring Diagramsin for complete
heated seat system wiring diagrams.
(1) Remove the heated seat module from its
mounting location (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/MEMORY HEATED
SEAT/MIRROR MODULE - REMOVAL).NOTE: ANY RESISTANCE VALUES (OHMSV) GIVEN
IN THE FOLLOWING TEXT ARE SUPPLIED USING
THE AUTOMATIC RANGE GENERATED BY A
FLUKETAUTOMOTIVE METER. IF ANOTHER TYPE
OF MEASURING DEVICE IS USED THE VALUES
GENERATED MAY NOT BE THE SAME AS THE
RESULTS SHOWN HERE, OR MAY HAVE TO BE
CONVERTED TO THE RANGE USED HERE.
RIGHT SEAT HEATER INOPERATIVE
(1) If a heated seat heats but one or both indicator
lamps (LED's) on the heated seat switch fail to illu-
minate, check the driver circuit with the inoperative
LED for a short to ground. If OK, replace the heated
seat switch. If NOT OK repair the short to ground as
required and than replace the heated seat switch.
NOTE: IF THE RIGHT SEAT CUSHION IS ALREADY
WARM THE FOLLOWING STEP WILL NOT PROVE
CONCLUSIVE.
(2) Back-probe the heated seat module wire har-
ness connector (Fig. 15), do not disconnect. Check
cavity #3 for battery voltage when the right heated
seat switch is turned ªONº, voltage should be
present, If OK go to Step 3 If NOT OK, test the right
heated seat switch (Refer to 8 - ELECTRICAL/
HEATED SEATS/PASSENGER HEATED SEAT
SWITCH - DIAGNOSIS AND TESTING). If the
switch tests OK, check for continuity between the
switch and control module on the MUX circuit, If OK
replace the heated seat control module. If NOT OK,
repair the open or shorted MUX circuit as required.
Fig. 15 Heated Seat Module Electrical Connector
8E - 22 ELECTRONIC CONTROL MODULESKJ
HEATED SEAT MODULE (Continued)

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION.........................10
OPERATION...........................10
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM............................11
DRIVER SEAT HEATER SWITCH
DESCRIPTION.........................11
OPERATION...........................12
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH............................12
REMOVAL.............................13
INSTALLATION.........................13
HEATED SEAT ELEMENT
DESCRIPTION.........................13OPERATION...........................13
DIAGNOSIS AND TESTING - HEATED SEAT
ELEMENT...........................13
HEATED SEAT SENSOR
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR............................14
PASSENGER SEAT HEATER SWITCH
DESCRIPTION.........................14
OPERATION...........................14
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH............................14
REMOVAL.............................15
INSTALLATION.........................15
HEATED SEAT SYSTEM
DESCRIPTION
Individually controlled electrically heated front
seats are available on models that are also equipped
with the optional leather trim package. Vehicles with
this option can be visually identified by the two sep-
arate heated seat switches mounted on the outboard
seat cushion side shields. The heated seat system
allows the front seat driver and passenger to select
from two different levels of supplemental electrical
seat heating, or no seat heating to suit their individ-
ual comfort requirements. The heated seat system for
this vehicle includes the following major components:
²Heated Seat Switches- Two heated seat
switches are used per vehicle, including two Light-
Emitting Diode (LED) indicator lamps and an incan-
descent back lighting bulb for each switch. One
switch for the driver and one for the passenger front
seats. The switches are mounted on the outboard
seat cushion side shields.
²Heated Seat Module- also referred to as the
Seat Heat Interface Module (SHIM), this module con-
tains the solid state electronic control and diagnostic
logic circuitry for the heated seat system. One heated
seat module is used per vehicle and is mounted
under the left front seat cushion. Refer to the Elec-
tronic Control Modules section of the service manual
for heated seat module information.
²Heated Seat Elements- Four heated seat ele-
ments are used per vehicle, one for each front seat
back and one for each front seat cushion. The ele-
ments are integral to the individual front seat andseat back cushions and cannot be removed from the
cushions, once installed at the factory.
²Heated Seat Sensors- Two heated seat sen-
sors are used per vehicle, one for each front seat. The
sensors are integral to the individual front seat heat-
ing elements.
Following are general descriptions of the major
components in the heated seat system. See the own-
er's manual in the vehicle glove box for more infor-
mation on the features, use and operation of the
heated seat system. Refer toWiring Diagramsfor
the location of complete heated seat system wiring
diagrams.
OPERATION
The heated seat module receives fused battery cur-
rent through fuse #29 in the Junction Block (JB)
when the ignition switch is in the ªONº position. The
heated seat switches receive battery current through
fuse #25 in the Junction Block also, when the igni-
tion switch is in the ªONº position. The heated seat
module shares a common ground circuit with each of
the heated seat elements. The heated seat elements
will only operate when the surface temperature of
the seat cushion is below the designed temperature
set points of the system.
The heated seat system will also be turned off
automatically whenever the ignition switch is turned
to any position except On. If the ignition switch is
turned to the Off position while a heated seat is
turned ON, the heated seat will remain Off after the
ignition switch is turned back ªONº until a heated
seat switch is depressed again.
8G - 10 HEATED SEAT SYSTEMKJ

The heated seat module monitors inputs from the
heated seat sensors and the heated seat switches. In
response to these inputs the heated seat module uses
its internal programming to control outputs to the
heated seat elements in both front seats and to con-
trol the heated seat LED indicator lamps located in
both of the heated seat switches. The heated seat
module is also programmed to provide self-diagnostic
capability. When the module detects certain failures
within the heated seat system, it will provide a
visual indication of the failure by flashing the indica-
tor lamps in the affected heated seat switch. The
heated seat module will automatically turn off the
heated seat elements if it detects a short or open in
the heated seat element circuit or a heated seat sen-
sor value that is out of range.
DIAGNOSIS AND TESTING - HEATED SEAT
SYSTEM
HEATED SEAT SYSTEM SELF-DIAGNOSIS
The heated seat system is capable of performing
some self-diagnostics. The following table depicts the
various monitored failures which will be reported to
the vehicle operator or technician by flashing the
individual heated seat switch Light Emitting Diode
(LED) indicator lamps. Refer to the Heated Seat Sys-
tem Self-Diagnosis table for failure identification.
The driver side heated seat switch indicator lamps
will flash if a failure occurs in the driver side heated
seat, and the passenger side heated seat switch indi-
cator lamps will flash for a passenger side heated
seat failure. If a monitored heated seat system fail-
ure occurs, the switch indicator lamps will flash at a
pulse rate of about one-half second on, followed by
about one-half second off for a duration of about one
minute after the switch for the faulty heated seat is
depressed in either the Low or High direction. This
process will repeat every time the faulty heated seat
switch is actuated until the problem has been cor-
rected.
Heated Seat System Self-Diagnosis
Monitored FailureSwitch High
Indicator LampSwitch Low
Indicator Lamp
Heated Seat
Element ShortedFlashing Flashing
Heated Seat
Element OpenFlashing Off
Heated Seat
Sensor Value Out
of RangeOff FlashingIf the heated seat system failure is identified by
flashing heated seat switch indicator lamps, go to the
appropriate diagnosis and testing procedure in this
section and confirm the condition, using the step by
step procedure. If the monitored failure is confirmed,
replace the component. If the monitored failure is not
confirmed, replace the heated seat module with a
known good unit and retest the system.
HEATED SEAT SYSTEM TESTING
Refer toWiring Diagramsfor the location of com-
plete heated seat system wiring diagrams. Before
testing the individual components in the heated seat
system, perform the following preliminary checks:
²If a single indicator lamp for one heated seat
switch does not operate and the heated seat elements
do heat, refer toDiagnosis and Testing the
Heated Seat Switchin this section for the location
of heated seat switch diagnosis and testing proce-
dures.
²If both indicator lamps for a heated seat switch
operate, but the heated seat elements do not heat,
refer toDiagnosis and Testing the Heated Seat
Modulein Electronic Control Modules for the loca-
tion of heated seat module diagnosis and testing pro-
cedures.
²If an indicator lamp on either heated seat switch
remains illuminated after the heated seat has been
turned Off, refer toDiagnosis and Testing the
Heated Seat Modulein Electronic Control Modules
for the location of heated seat module diagnosis and
testing procedures. Also refer to the Body Diagnostic
Manual for additional diagnosis and testing proce-
dures.
DRIVER SEAT HEATER
SWITCH
DESCRIPTION
The heated seat switches are located on the out-
board cushion side shield of the driver and passenger
front seats (Fig. 1). The two, three-position rocker
type switches provide a resistor multiplexed signal to
the Heated Seat Module through separate hard wired
circuits. Each switch has an Off, Low and High set-
ting. Each switch contains two light emitting diodes
(LED), one for each High and Low setting to let the
occupant know that the seat heater system is on.
The heated seat switches and their LED's cannot
be repaired. If either switch is faulty or damaged the
entire switch must be replaced.
KJHEATED SEAT SYSTEM 8G - 11
HEATED SEAT SYSTEM (Continued)

HEATED SEAT SENSOR
DIAGNOSIS AND TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWIRING.
NOTE: ANY RESISTANCE VALUES (OHMSV) GIVEN
IN THE FOLLOWING TEXT ARE SUPPLIED USING
THE AUTOMATIC RANGE GENERATED BY A
FLUKETAUTOMOTIVE METER. IF ANOTHER TYPE
OF MEASURING DEVICE IS USED THE VALUES
GENERATED MAY NOT BE THE SAME AS THE
RESULTS SHOWN HERE, OR MAY HAVE TO BE
CONVERTED TO THE RANGE USED HERE.
(1) Disconnect the heated seat wire harness con-
nector from under the seat. Using an ohmmeter,
check the resistance between the heated seat sensor
input circuit cavity and the heated seat sensor feed
circuit cavity in the heated seat wire harness connec-
tor. The heated seat sensor resistance should be
between 1 kilohm and 100 kilohms. If OK, go to Step
2. If not OK, replace the faulty seat heating element
assembly.
(2) Test the seat wire harness between the heated
seat module connector and the heated seat wire har-
ness connector for a shorted or open circuit. If OK,
refer toDiagnosis and Testing the Heated Seat
Modulein Electronic Control Modules, for the
proper heated seat module diagnosis and testing pro-
cedures. If not OK, repair the shorted or open heated
seat wire harness as required.
PASSENGER SEAT HEATER
SWITCH
DESCRIPTION
The heated seat switches are located on the out-
board cushion side shield of the driver and passenger
front seats (Fig. 3). The two, three-position rocker
type switches provide a resistor multiplexed signal to
the Heated Seat Module through separate hard wired
circuits. Each switch has an Off, Low and High set-
ting. Each switch contains two light emitting diodes
(LED), one for each High and Low setting to let the
occupant know that the seat heater system is on.
The heated seat switches and their LED's cannot
be repaired. If either switch is faulty or damaged the
entire switch must be replaced.
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, and High.
When the front of the switch rocker is fullydepressed, the High position is selected and the high
position LED indicator illuminates. When the rear of
the switch rocker is fully depressed, the Low position
is selected and the low position LED indicator illumi-
nates. When the switch rocker is depressed a second
time in either direction, Off is selected and both LED
indicators are extinguished.
Both switches provide separate resistor multi-
plexed hard wire inputs to the Heated Seat Module
to indicate the selected switch position. The heated
seat module monitors the switch inputs and responds
to the heated seat switch status messages by control-
ling the output to the seat heater elements of the
selected seat. The Low heat position set point is
about 36É C (97É F), and the High heat position set
point is about 41É C (105É F).
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH
If a heated seat fails to heat and one or both of the
indicator lamps on a heated seat switch flash, refer
toHeated Seat System Diagnosis and Testingin
this section for flashing LED failure identification.
Refer toWiring Diagramsfor complete heated seat
system wiring diagrams.
(1) If the problem being diagnosed involves a
heated seat switch indicator lamp that remains illu-
minated after the heated seat has been turned Off,
refer toDiagnosis and Testing the Heated Seat
Modulein the Electronic Control Modules section for
heated seat module diagnosis and testing procedures.
If not, go to Step 2
Fig. 3 KJ POWER / HEATED SEAT
8G - 14 HEATED SEAT SYSTEMKJ

fused panel lamps dimmer switch signal circuit. The
cluster illumination lamps are grounded at all times.
In addition, the control ring on the left (lighting)
control stalk of the multi-function switch has a
Parade Mode position to provide a parade mode. The
BCM monitors the request for this mode from the
multi-function switch, then sends an electronic dim-
ming level message to the EMIC over the PCI data
bus to illuminate all VFDs in the vehicle at full
intensity for easier visibility when driving in daylight
with the exterior lighting turned On.
The hard wired cluster illumination lamp circuits
may be diagnosed using conventional diagnostic
methods. However, proper testing of the PWM output
of the EMIC and the electronic dimming level mes-
sages sent by the BCM over the PCI data bus
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
CHIME WARNING SERVICE The EMIC is pro-
grammed to provide chime service when certain indi-
cators are illuminated. When the programmed
conditions are met, the EMIC generates an electronic
chime tone through its integral chime tone generator.
In addition, the EMIC is programmed to provide
chime service for other electronic modules in the
vehicle when it receives the proper electronic chime
request messages over the PCI data bus. Upon
receiving the proper chime request message, the
EMIC activates the integral chime tone generator to
provide the audible chime tone to the vehicle opera-
tor. (Refer to 8 - ELECTRICAL/CHIME/BUZZER -
OPERATION). Proper testing of the EMIC and the
PCI data bus chime request message functions
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER
If all of the instrument cluster gauges and/or indi-
cators are inoperative, refer to PRELIMINARY
DIAGNOSIS . If an individual gauge or Programma-
ble Communications Interface (PCI) data bus mes-
sage-controlled indicator is inoperative, refer to
ACTUATOR TEST . If an individual hard wired indi-
cator is inoperative, refer to the diagnosis and testing
information for that specific indicator. If the instru-
ment cluster chime service is inoperative, refer to
CHIME SERVICE DIAGNOSIS . If the instrument
cluster illumination lighting is inoperative, refer to
CLUSTER ILLUMINATION DIAGNOSIS . Refer to
the appropriate wiring information. The wiring infor-
mation includes wiring diagrams, proper wire and
connector repair procedures, details of wire harness
routing and retention, connector pin-out information
and location views for the various wire harness con-
nectors, splices and grounds.NOTE: Certain indicators in this instrument cluster
are automatically configured. This feature allows
those indicators to be activated for compatibility
with certain optional equipment. If the problem
being diagnosed involves illumination of the ABS
indicator, the airbag indicator, or the SKIS indicator
when the vehicle does not have this equipment, a
DRBIIITscan tool must be used to disable the erro-
neous indicator(s). Refer to the appropriate diag-
nostic information.
PRELIMINARY DIAGNOSIS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Check the fused B(+) fuse (Fuse 34 - 15
ampere) in the Junction Block (JB). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
(Fuse 34 - 15 ampere) in the JB. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(3) Disconnect and isolate the battery negative
cable. Remove the instrument cluster. Reconnect the
battery negative cable. Check for battery voltage at
the fused B(+) circuit cavity of the instrument panel
wire harness connector for the instrument cluster. If
OK, go to Step 4. If not OK, repair the open fused
B(+) circuit between the instrument cluster and the
JB as required.
(4) Check the fused ignition switch output (run-
start) fuse (Fuse 13 - 10 ampere) in the JB. If OK, go
to Step 5. If not OK, repair the shorted circuit or
component as required and replace the faulty fuse.
(5) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run-start) fuse (Fuse 13 - 10 ampere) in the
JB. If OK, go to Step 6. If not OK, repair the open
KJINSTRUMENT CLUSTER 8J - 7
INSTRUMENT CLUSTER (Continued)

fluid level is not low), or until the ignition switch is
turned to the Off position, whichever occurs first.
²Brake Fluid Level Switch Input Fault- The
brake fluid level switch also features a 1 kilohm
diagnostic resistor connected in parallel between the
switch input and output to provide the cluster with
verification that the red brake warning indicator
driver circuit is not open. If the cluster does not see a
proper input on the red brake warning indicator
driver circuit, it will turn on the brake indicator. The
indicator remains illuminated until the red brake
warning indicator driver circuit fault is resolved, or
until the ignition switch is turned to the Off position,
whichever occurs first.
²Actuator Test- Each time the instrument clus-
ter is put through the actuator test, the brake indi-
cator will be turned on, then off again during the
bulb check portion of the test to confirm the function-
ality of the LED and the cluster control circuitry.
The park brake switch on the park brake pedal
mechanism provides a hard wired ground input to
the instrument cluster circuitry through the park
brake switch sense circuit whenever the park brake
is applied or not fully released. The brake fluid level
switch on the brake master cylinder reservoir pro-
vides a hard wired ground input to the instrument
cluster circuitry through the red brake warning indi-
cator driver circuit whenever the fluid level in the
reservoir becomes low. On models equipped with the
optional ABS, the CAB sends the proper lamp-on or
lamp-off messages to the instrument cluster. If the
CAB sends a lamp-on message after the bulb test, it
indicates that the CAB has detected a brake hydrau-
lic system malfunction and/or that the ABS system
has become inoperative. The CAB will store a Diag-
nostic Trouble Code (DTC) for any malfunction it
detects.
For further diagnosis of the brake indicator or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). The park brake
switch input to the instrument cluster can be diag-
nosed using conventional diagnostic tools and meth-
ods. For proper diagnosis of the brake fluid level
switch input to the instrument cluster, the antilock
brake system, the CAB, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the brake indicator, a DRBIIItscan tool
is required. Refer to the appropriate diagnostic infor-
mation.
DIAGNOSIS AND TESTING - BRAKE INDICATOR
The diagnosis found here addresses an inoperative
brake indicator condition. If there are problems with
several indicators in the instrument cluster, (Refer to
8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAG-NOSIS AND TESTING). If the brake indicator stays
on with the ignition switch in the On position and
the park brake released, or comes on while driving,
(Refer to 5 - BRAKES - DIAGNOSIS AND TEST-
ING). If no brake system problem is found, the fol-
lowing procedures will help to locate a shorted or
open circuit, or a faulty park brake switch input.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE SUPPLEMENTAL RESTRAINT
SYSTEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, DRIVER AIRBAG,
PASSENGER AIRBAG, SEAT BELT TENSIONER,
FRONT IMPACT SENSORS, SIDE CURTAIN AIRBAG,
OR INSTRUMENT PANEL COMPONENT DIAGNOSIS
OR SERVICE. DISCONNECT AND ISOLATE THE
BATTERY NEGATIVE (GROUND) CABLE, THEN
WAIT TWO MINUTES FOR THE SYSTEM CAPACI-
TOR TO DISCHARGE BEFORE PERFORMING FUR-
THER DIAGNOSIS OR SERVICE. THIS IS THE ONLY
SURE WAY TO DISABLE THE SUPPLEMENTAL
RESTRAINT SYSTEM. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
INDICATOR ILLUMINATES DURING BULB TEST, BUT DOES
NOT WHEN PARK BRAKE APPLIED
(1) Disconnect and isolate the battery negative
cable. Disconnect the front body wire harness connec-
tor for the park brake switch from the switch termi-
nal. Apply the parking brake. Check for continuity
between the park brake switch terminal and a good
ground. There should be continuity. If OK, go to Step
2. If not OK, replace the faulty park brake switch.
(2) Disconnect the instrument panel wire harness
connector for the instrument cluster from the cluster
connector receptacle. Check for continuity between
the park brake switch sense circuit cavities of the
front body wire harness connector for the park brake
switch and the instrument panel wire harness con-
nector for the instrument cluster. There should be
continuity. If not OK, repair the open park brake
switch sense circuit between the park brake switch
and the instrument cluster as required.
INDICATOR REMAINS ILLUMINATED - BRAKE SYSTEM
CHECKS OK
(1) Disconnect and isolate the battery negative
cable. Disconnect the front body wire harness connec-
8J - 14 INSTRUMENT CLUSTERKJ
BRAKE/PARK BRAKE INDICATOR (Continued)