2002 DODGE RAM instrument panel

(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cluster bezel from the instrument
panel. Refer toCluster Bezelin the index of this
service manual for the location of the proper cluster
bezel removal procedures.
(3) Remove the three screws that secure the
heated seat switch bezel to the instrument panel
(Fig. 19).
(4) Pull the heated seat switch bezel out from the
instrument panel far enough to access and disconnect
the two instrument panel wire harness connectors
from the connector receptacles on the backs of the
heated seat switches.
(5) Remove the heated seat switch bezel and both
switches from the instrument panel as a unit.(6) From the back of the heated seat switch bezel,
gently push the heated seat switch out through the
front of the bezel.
INSTALLATION
Both heated seat switches and the heated seat
switch bezel are available individually for service
replacement.
NOTE: When installing the heated seat switches, be
certain they are installed in the proper mounting
holes of the heated seat switch bezel. Note that the
driver side and passenger side switches are identi-
cal in appearance except for the keyway in the con-
nector receptacle on the backs of the switches. The
driver side switch has the keyway located near the
bottom of the connector receptacle and should be
installed in the left mounting hole of the heated
seat switch bezel. The passenger side switch has
the keyway located near the top of the connector
receptacle and should be installed in the right
mounting hole of the heated seat switch bezel.
(1) From the front of the heated seat switch bezel,
align the back of the heated seat switch with the
proper mounting hole in the heated seat switch bezel
and gently push the switch into the bezel until it
snaps into place.
(2) Position the heated seat switch bezel and both
switches to the instrument panel as a unit.
(3) Reconnect the two instrument panel wire har-
ness connectors to the connector receptacles on the
backs of the heated seat switches.
(4) Position the heated seat switch bezel and both
switches in the instrument panel mounting hole as a
unit.
(5) Install and tighten the three screws that secure
the heated seat switch bezel to the instrument panel.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(6) Install the cluster bezel onto the instrument
panel. Refer toCluster Bezelin the index of this
service manual for the location of the proper cluster
bezel installation procedures.
(7) Reconnect the battery negative cable.
Fig. 19 Heated Seat Switch and Bezel Remove/
Install
1 - INSTRUMENT PANEL
2 - SCREW (3)
3 - HEATED SEAT SWITCHES AND BEZEL UNIT
BR/BEHEATED SEAT SYSTEM 8G - 19
PASSENGER SEAT HEATER SWITCH (Continued)

INSTALLATION
(1) Position the horn and mounting bracket unit(s)
onto the right fender wheel house front extension.
(2) Install and tighten the screw that secures the
horn and mounting bracket unit(s) to the right
fender wheel house front extension. Tighten the
screw to 11 N´m (95 in. lbs.).
(3) Reconnect the wire harness connector(s) to the
horn connector receptacle(s).
(4) Reconnect the battery negative cable.
HORN RELAY
DESCRIPTION
The horn relay is a electromechanical device that
switches battery current to the horn when the horn
switch grounds the relay coil. The horn relay is
located in the Power Distribution Center (PDC) in
the engine compartment. If a problem is encountered
with a continuously sounding horn, it can usually be
quickly resolved by removing the horn relay from the
PDC until further diagnosis is completed. See the
fuse and relay layout label affixed to the inside sur-
face of the PDC cover for horn relay identification
and location.
The horn relay is a International Standards Orga-
nization (ISO) micro-relay. Relays conforming to the
ISO specifications have common physical dimensions,
current capacities, terminal patterns, and terminal
functions. The ISO micro-relay terminal functions
are the same as a conventional ISO relay. However,
the ISO micro-relay terminal pattern (or footprint) is
different, the current capacity is lower, and the phys-
ical dimensions are smaller than those of the conven-
tional ISO relay.
The horn relay cannot be repaired or adjusted and,
if faulty or damaged, it must be replaced.
OPERATION
The ISO relay consists of an electromagnetic coil, a
resistor or diode, and three (two fixed and one mov-
able) electrical contacts. The movable (common feed)
relay contact is held against one of the fixed contacts
(normally closed) by spring pressure. When the elec-
tromagnetic coil is energized, it draws the movable
contact away from the normally closed fixed contact,
and holds it against the other (normally open) fixed
contact.
When the electromagnetic coil is de-energized,
spring pressure returns the movable contact to the
normally closed position. The resistor or diode is con-
nected in parallel with the electromagnetic coil in the
relay, and helps to dissipate voltage spikes that are
produced when the coil is de-energized.
DIAGNOSIS AND TESTING - HORN RELAY
The horn relay (Fig. 2) is located in the Power Dis-
tribution Center (PDC) behind the battery on the
driver side of the engine compartment. If a problem
is encountered with a continuously sounding horn, it
can usually be quickly resolved by removing the horn
relay from the PDC until further diagnosis is com-
pleted. See the fuse and relay layout label affixed to
the inside surface of the PDC cover for horn relay
identification and location. For complete circuit dia-
grams, refer to the appropriate wiring information.
The wiring 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, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Remove the horn relay from the PDC. (Refer to
8 - ELECTRICAL/HORN/HORN RELAY -
REMOVAL) for the procedures.
(2) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 3. If not OK, replace the faulty relay.
(3) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
4. If not OK, replace the faulty relay.
(4) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, perform the Relay Circuit Test that
follows. If not OK, replace the faulty relay.
RELAY CIRCUIT TEST
(1) The relay common feed terminal cavity (30) is
connected to battery voltage and should be hot at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is
connected to terminal 30 in the de-energized position,
but is not used for this application. Go to Step 3.
(3) The relay normally open terminal (87) is con-
nected to the common feed terminal (30) in the ener-
gized position. This terminal supplies battery voltage
to the horn(s). There should be continuity between
the cavity for relay terminal 87 and the horn relay
output circuit cavity of each horn wire harness con-
BR/BEHORN 8H - 3
HORN (Continued)

the horn switch is damaged or faulty, or if the driver
side airbag is deployed, the driver side airbag module
trim cover and horn switch must be replaced as a
unit.
OPERATION
When the center area of the driver side airbag trim
cover is depressed, the electrically conductive grids
on the facing surfaces of the horn switch membranes
contact each other, closing the switch circuit. The
completed horn switch circuit provides a ground for
the control coil side of the horn relay, which activates
the relay. When the horn switch is released, the
resistive tension of the convex membrane separates
the two electrically conductive grids and opens the
switch circuit.
DIAGNOSIS AND TESTING - HORN SWITCH
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring 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 connec-
tors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTSBEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the steering column opening cover
from the instrument panel.
(2) Check for continuity between the metal steer-
ing column jacket and a good ground. There should
be continuity. If OK, go to Step 3. If not OK,(Refer to
19 - STEERING/COLUMN - INSTALLATION) for
proper installation of the steering column.
(3) Remove the driver side airbag module from the
steering wheel. Disconnect the horn switch wire har-
ness connectors from the driver side airbag module.
(4) Remove the horn relay from the Power Distri-
bution Center (PDC). Check for continuity between
the steering column half of the horn switch feed wire
harness connector and a good ground. There should
be no continuity. If OK, go to Step 5. If not OK,
repair the shorted horn relay control circuit to the
horn relay in the PDC as required.
(5) Check for continuity between the steering col-
umn half of the horn switch feed wire harness con-
nector and the horn relay control circuit cavity for
the horn relay in the PDC. There should be continu-
ity. If OK, go to Step 6. If not OK, repair the open
horn relay control circuit to the horn relay in the
PDC as required.
(6) Check for continuity between the horn switch
feed wire and the horn switch ground wire on the
driver side airbag module. There should be no conti-
nuity. If OK, go to Step 7. If not OK, replace the
faulty horn switch.
(7) Depress the center of the driver side airbag
module trim cover and check for continuity between
the horn switch feed wire and the horn switch
ground wire on the driver side airbag module. There
should now be continuity. If not OK, replace the
faulty horn switch.REMOVAL
If the horn switch is damaged or faulty, or if the
driver side airbag is deployed, the driver side airbag
module trim cover and horn switch must be replaced
as a unit. (Refer to 8 - ELECTRICAL/RESTRAINTS/
DRIVER AIRBAG - REMOVAL).
Fig. 4 Driver Side Airbag Module Trim Cover and
Horn Switch
1 - RETAINER SLOTS
2 - LOCKING BLOCKS
3 - RETAINER SLOTS
4 - HORN SWITCH
BR/BEHORN 8H - 5
HORN SWITCH (Continued)

INSTRUMENT CLUSTER
DESCRIPTION
The instrument cluster for this model is an Elec-
troMechanical Instrument Cluster (EMIC) module
that is located in the instrument panel above the
steering column opening, directly in front of the
driver (Fig. 1). The EMIC gauges and indicators are
protected by an integral clear plastic cluster lens,
and are visible through a dedicated opening in the
cluster bezel on the instrument panel. Just behind
the cluster lens is the cluster hood. The cluster hood
serves as a visor and shields the face of the cluster
from ambient light and reflections to reduce glare.
Behind the cluster hood is the cluster overlay and
gauges. The overlay is a multi-layered unit. The
dark, visible surface of the outer layer of the overlay
is marked with all of the gauge identification and
graduations, but this layer is also translucent. The
darkness of this outer layer prevents the cluster from
appearing cluttered or busy by concealing the cluster
indicators that are not illuminated, while the trans-
lucence of this layer allows those indicators and icons
that are illuminated to be readily visible. The under-
lying layer of the overlay is opaque and allows light
from the various indicators and illumination lamps
behind it to be visible through the outer layer of the
overlay only through predetermined cutouts. On the
lower edge of the cluster lens just left of center, the
odometer/trip odometer switch knob protrudesthrough a dedicated hole in the lens. The remainder
of the EMIC, including the mounts and the electrical
connections, are concealed behind the cluster bezel.
The molded plastic EMIC housing has four integral
mounting tabs, two each on the upper and lower
edges of the housing. The EMIC is secured to the
molded plastic instrument panel cluster carrier with
four screws. All electrical connections to the EMIC
are made at the back of the cluster housing through
two take outs of the instrument panel wire harness,
each equipped with a self-docking connector.
A single EMIC module is offered on this model.
This module utilizes integrated circuitry and infor-
mation carried on the Chrysler Collision Detection
(CCD) data bus network for control of all gauges and
many of the indicators. (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/COMMUNI-
CATION - DESCRIPTION). The EMIC also uses
several hard wired inputs in order to perform its
many functions. In addition to instrumentation and
indicators, the EMIC has hardware and/or software
to support the following functions:
²Chime Warning Requests- The EMIC sends
chime tone requests over a hard wired circuit to the
Central Timer Module (CTM) when it monitors cer-
tain conditions or inputs. The CTM replaces the
chime or buzzer module and performs the functions
necessary to provide audible alerts that are synchro-
nized with the visual alerts provided by the EMIC.
(Refer to 8 - ELECTRICAL/CHIME/BUZZER -
DESCRIPTION).
²Vacuum Fluorescent Display (VFD) Dim-
ming Service- The EMIC performs the functions
necessary to eliminate the need for a separate VFD
dimming module by providing control and synchroni-
zation of the illumination intensity of all vacuum flu-
orescent displays in the vehicle, as well as a parade
mode.
The EMIC module incorporates a blue-green digital
VFD for displaying odometer and trip odometer infor-
mation, as well as the amber cruise-on indicator dis-
play function. Some variations of the EMIC are
necessary to support optional equipment and regula-
tory requirements. The EMIC includes the following
analog gauges:
²Coolant Temperature Gauge
²Fuel Gauge
²Oil Pressure Gauge
²Speedometer
²Tachometer
²Voltage Gauge
The EMIC also includes provisions for the follow-
ing indicators:
²Airbag Indicator
²Antilock Brake System (ABS) Indicator
²Brake Indicator
Fig. 1 Instrument Cluster Components
1 - COVER
2 - HOUSING
3 - MASK AND GAUGES
4 - HOOD
5 - LENS
6 - CIRCUIT BOARD
7 - ODOMETER RESET BUTTON
8J - 2 INSTRUMENT CLUSTERBR/BE

²Check Gauges Indicator
²Cruise Indicator (Odometer VFD)
²Four-Wheel Drive Indicator
²High Beam Indicator
²Low Fuel Indicator
²Washer Fluid Indicator
²Malfunction Indicator Lamp (MIL)
²Overdrive-Off Indicator
²Seatbelt Indicator
²Service Reminder Indicator (SRI)
²Transmission Overtemp Indicator
²Turn Signal (Right and Left) Indicators
²Upshift Indicator
²Wait-To-Start Indicator (Diesel Only)
²Water-In-Fuel Indicator (Diesel Only)
Some of these indicators are either programmable
or automatically configured when the EMIC is con-
nected to the vehicle electrical system. This feature
allows those indicators to be activated or deactivated
for compatibility with certain optional equipment.
The EMIC also includes a provision for mounting the
automatic transmission gear selector indicator in the
lower right corner of the cluster. The spring-loaded,
cable driven, mechanical gear selector indicator gives
an indication of the transmission gear that has been
selected with the automatic transmission gear selec-
tor lever. The gear selector indicator pointer is easily
visible through an opening provided in the front of
the cluster overlay, and is also lighted by the cluster
illumination lamps for visibility at night. Models
equipped with a manual transmission have a block-
out plate installed in place of the gear selector indi-
cator.
Cluster illumination is accomplished by adjustable
incandescent back lighting, which illuminates the
gauges for visibility when the exterior lighting is
turned on. The EMIC high beam indicator, turn sig-
nal indicators, and wait-to-start indicator are also
illuminated by dedicated incandescent bulbs. The
remaining indicators in the EMIC are each illumi-
nated by a dedicated Light Emitting Diode (LED)
that is soldered onto the electronic circuit board.
Each of the incandescent bulbs is secured by an inte-
gral bulb holder to the electronic circuit board from
the back of the cluster housing.
Hard wired circuitry connects the EMIC to the
electrical system of the vehicle. These hard wired cir-
cuits are integral to several wire harnesses, which
are routed throughout the vehicle and retained by
many different methods. These circuits may be con-
nected to each other, to the vehicle electrical system
and to the EMIC 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 infor-
mation. The wiring information includes wiring dia-grams, proper wire and connector repair procedures,
further details on wire harness routing and reten-
tion, as well as pin-out and location views for the
various wire harness connectors, splices and grounds.
The EMIC modules for this model are serviced only
as complete units. The EMIC module cannot be
adjusted or repaired. If a gauge, an LED indicator,
the VFD, the electronic circuit board, the circuit
board hardware, the cluster overlay, or the EMIC
housing are damaged or faulty, the entire EMIC mod-
ule must be replaced. The cluster lens and hood unit,
the rear cluster housing cover, the automatic trans-
mission gear selector indicator, and the incandescent
lamp bulbs with holders are available for individual
service replacement.
OPERATION
The ElectroMechanical Instrument Cluster (EMIC)
is designed to allow the vehicle operator to monitor
the conditions of many of the vehicle components and
operating systems. The gauges and indicators in the
EMIC provide valuable information about the various
standard and optional powertrains, fuel and emis-
sions systems, cooling systems, lighting systems,
safety systems and many other convenience items.
The EMIC is installed in the instrument panel so
that all of these monitors can be easily viewed by the
vehicle operator when driving, while still allowing
relative ease of access for service. The microproces-
sor-based EMIC hardware and software uses various
inputs to control the gauges and indicators visible on
the face of the cluster. Some of these inputs are hard
wired, but most are in the form of electronic mes-
sages that are transmitted by other electronic mod-
ules over the Chrysler Collision Detection (CCD) data
bus network. (Refer to 8 - ELECTRICAL/ELEC-
TRONIC CONTROL MODULES/COMMUNICATION
- OPERATION).
The EMIC microprocessor smooths the input data
using algorithms to provide gauge readings that are
accurate, stable and responsive to operating condi-
tions. These algorithms are designed to provide
gauge readings during normal operation that are con-
sistent with customer expectations. However, when
abnormal conditions exist, such as low/high battery
voltage, low oil pressure, or high coolant tempera-
ture, the algorithm drives the gauge pointer to an
extreme position and the microprocessor turns on the
Check Gauges indicator to provide a distinct visual
indication of a problem to the vehicle operator. The
instrument cluster circuitry may also generate a
hard wired chime tone request to the Central Timer
Module (CTM) when it monitors certain conditions or
inputs, in order to provide the vehicle operator with
an audible alert.
BR/BEINSTRUMENT CLUSTER 8J - 3
INSTRUMENT CLUSTER (Continued)

The EMIC circuitry operates on battery current
received through a fused B(+) fuse in the Junction
Block (JB) on a non-switched fused B(+) circuit, and
on battery current received through a fused ignition
switch output (st-run) fuse in the JB on a fused igni-
tion switch output (st-run) circuit. This arrangement
allows the EMIC to provide some features regardless
of the ignition switch position, while other features
will operate only with the ignition switch in the Start
or On positions. The EMIC circuitry is grounded
through two separate ground circuits located in one
of the two instrument cluster connectors and take
outs of the instrument panel wire harness. One
ground circuit receives ground through a take out
with an eyelet terminal connector of the instrument
panel wire harness that is secured by a nut to a
ground stud located on the left instrument panel end
bracket, while the other ground circuit receives
ground through a take out with an eyelet terminal
connector of the instrument panel wire harness that
is secured by a nut to a ground stud located on the
back of the instrument panel armature above the
inboard side of the instrument panel steering column
opening.
The EMIC also has a self-diagnostic actuator test
capability, which will test each of the CCD bus mes-
sage-controlled functions of the cluster by lighting
the appropriate indicators and positioning the gauge
needles at several predetermined locations on the
gauge faces in a prescribed sequence. (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). See the owner's manual in the
vehicle glove box for more information on the fea-
tures, use and operation of the EMIC.
GAUGES
All gauges receive battery current through the
EMIC circuitry when the ignition switch is in the On
or Start positions. With the ignition switch in the Off
position battery current is not supplied to any
gauges, and the EMIC circuitry is programmed to
move all of the gauge needles back to the low end of
their respective scales. Therefore, the gauges do not
accurately indicate any vehicle condition unless the
ignition switch is in the On or Start positions. All of
the EMIC gauges, except the odometer, are air core
magnetic units. Two fixed electromagnetic coils are
located within each gauge. These coils are wrapped
at right angles to each other around a movable per-
manent magnet. The movable magnet is suspended
within the coils on one end of a pivot shaft, while the
gauge needle is attached to the other end of the
shaft. One of the coils has a fixed current flowing
through it to maintain a constant magnetic field
strength. Current flow through the second coil
changes, which causes changes in its magnetic fieldstrength. The current flowing through the second coil
is changed by the EMIC circuitry in response to mes-
sages received over the CCD data bus. The gauge
needle moves as the movable permanent magnet
aligns itself to the changing magnetic fields created
around it by the electromagnets.
The gauges are diagnosed using the EMIC self-di-
agnostic actuator test. (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the CCD data bus and
the data bus message inputs to the EMIC that con-
trol each gauge require the use of a DRBIIItscan
tool. Refer to the appropriate diagnostic information.
Specific operation details for each gauge may be
found elsewhere in this service manual.
VACUUM-FLUORESCENT DISPLAY
The Vacuum-Fluorescent Display (VFD) module is
soldered to the EMIC circuit board. The display is
active with the ignition switch in the On or Start
positions, and inactive when the ignition switch is in
any other position. The VFD has several display
capabilities including odometer, trip odometer, and
an amber ªCRUISEº indication whenever the
optional speed control system is turned On. The
cruise indicator function of the VFD is automatically
enabled or disabled by the EMIC circuitry based
upon whether the vehicle is equipped with the speed
control option. An odometer/trip odometer switch on
the EMIC circuit board is used to control several of
the display modes. This switch is actuated manually
by depressing the odometer/trip odometer switch
knob that extends through the lower edge of the clus-
ter lens, just right of center. Actuating this switch
momentarily with the ignition switch in the On posi-
tion will toggle the VFD between the odometer and
trip odometer modes. The word ªTRIPº will also
appear in blue-green text when the VFD trip odome-
ter mode is active. Depressing the switch button for
about two seconds while the VFD is in the trip odom-
eter mode will reset the trip odometer value to zero.
Holding this switch depressed while turning the igni-
tion switch from the Off position to the On position
will activate the EMIC self-diagnostic actuator test.
The EMIC will automatically flash the odometer or
trip odometer information on and off if there is a loss
of CCD data bus communication. The VFD will also
display various information used in several diagnos-
tic procedures. Refer to the appropriate diagnostic
information for additional details on this VFD func-
tion.
The VFD is diagnosed using the EMIC self-diag-
nostic actuator test. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND
TESTING). Proper testing of the CCD data bus and
the data bus message inputs to the EMIC that con-
8J - 4 INSTRUMENT CLUSTERBR/BE
INSTRUMENT CLUSTER (Continued)

trol some of the VFD functions requires the use of a
DRBIIItscan tool. Refer to the appropriate diagnos-
tic information. Specific operation details for the
odometer and trip odometer functions of the VFD
may be found elsewhere in this service manual.
INDICATORS
Indicators are located in various positions within
the EMIC and are all connected to the EMIC circuit
board. The four-wheel drive indicator, high beam
indicator, washer fluid indicator, turn signal indica-
tors, and wait-to-start indicator are hard wired. The
brake indicator is controlled by CCD data bus mes-
sages from the Controller Anti-lock Brake (CAB) and
the hard wired park brake switch input to the EMIC.
The seatbelt indicator is controlled by the EMIC pro-
gramming, CCD data bus messages from the Airbag
Control Module (ACM), and the hard wired seat belt
switch input to the EMIC. The Malfunction Indicator
Lamp (MIL) is normally controlled by CCD data bus
messages from the Powertrain Control Module
(PCM); however, if the EMIC loses CCD data bus
communications, the EMIC circuitry will automati-
cally turn the MIL on, and flash the odometer VFD
on and off repeatedly until CCD data bus communi-
cation is restored. The EMIC uses CCD data bus
messages from the Powertrain Control Module
(PCM), the diesel engine only Engine Control Module
(ECM), the ACM, and the CAB to control all of the
remaining indicators. Different indicators are con-
trolled by different strategies; some receive fused
ignition switch output from the EMIC circuitry clus-
ter and have a switched ground, while others are
grounded through the EMIC circuitry and have a
switched battery feed.
In addition, certain indicators in this instrument
cluster are programmable or configurable. This fea-
ture allows the programmable indicators to be acti-
vated or deactivated with a DRBIIItscan tool, while
the configurable indicators will be automatically
enabled or disabled by the EMIC circuitry for com-
patibility with certain optional equipment. The only
programmable indicator for this model is the upshift
indicator. The cruise indicator, four-wheel drive indi-
cator, overdrive-off indicator, service reminder indica-
tor, and the transmission overtemp indicator are
automatically configured, either electronically or
mechanically.
The hard wired indicators are diagnosed using con-
ventional diagnostic methods. The EMIC and CCD
bus message controlled indicator lamps are diagnosed
using the EMIC self-diagnostic actuator test. (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). Proper testing of the
CCD data bus and the data bus message inputs to
the EMIC that control each indicator lamp requirethe use of a DRBIIItscan tool. Refer to the appro-
priate diagnostic information. Specific operation
details for each indicator may be found elsewhere in
this service manual.
CLUSTER ILLUMINATION
The EMIC has several illumination lamps that are
illuminated when the exterior lighting is turned on
with the headlamp switch. The illumination bright-
ness of these lamps is adjusted by the panel lamps
dimmer rheostat when the headlamp switch thumb-
wheel is rotated (down to dim, up to brighten). The
illumination lamps receive battery current through
the panel lamps dimmer rheostat and a fuse in the
JB on a fused panel lamps dimmer switch signal cir-
cuit. The illumination lamps are grounded at all
times.
In addition, an analog/digital (A/D) converter in
the EMIC converts the analog panel lamps dimmer
rheostat input from the headlamp switch to a digital
dimming level signal for controlling the lighting level
of the VFD. The EMIC also broadcasts this digital
dimming information as a message over the CCD
data bus for use by the Compass Mini-Trip Computer
(CMTC) in synchronizing the lighting level of its
VFD with that of the EMIC. The headlamp switch
thumbwheel also has a Parade position to provide a
parade mode. The EMIC monitors the request for
this mode through a hard wired day brightness sense
circuit input from the headlamp switch. In this mode,
the EMIC will override the selected panel dimmer
switch signal and send a message over the CCD data
bus to illuminate all vacuum fluorescent displays at
full brightness for easier visibility when driving in
daylight with the exterior lighting turned on. The
parade mode has no effect on the incandescent bulb
illumination intensity.
The hard wired cluster illumination lamps are
diagnosed using conventional diagnostic methods.
Proper testing of the VFD dimming level and the
CCD data bus dimming level message functions
requires the use of a DRBIIItscan tool. Refer to the
appropriate diagnostic information.
CHIME WARNING REQUESTS
The EMIC is programmed to request chime service
from the Central Timer Module (CTM) when certain
indicator lamps are illuminated. When the pro-
grammed conditions are met, the EMIC generates a
chime request signal and sends it over a hard wired
tone request circuit to the CTM. Upon receiving the
proper chime request, the CTM activates an integral
chime tone generator to provide the audible chime
tone to the vehicle operator. (Refer to 8 - ELECTRI-
CAL/CHIME/BUZZER - OPERATION). Proper test-
ing of the CTM and the EMIC chime requests
BR/BEINSTRUMENT CLUSTER 8J - 5
INSTRUMENT CLUSTER (Continued)

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 Chrysler Col-
lision Detection (CCD) data bus message-controlled
indicator is inoperative, refer to ACTUATOR TEST .
If an individual hard wired indicator is inoperative,
refer to the diagnosis and testing information for
that specific indicator. If the instrument cluster
chime warning request function is inoperative, refer
to CHIME WARNING REQUEST DIAGNOSIS . If
the instrument cluster illumination lighting is inop-
erative, refer to CLUSTER ILLUMINATION DIAG-
NOSIS . If the instrument cluster Vacuum-
Fluorescent Display (VFD) dimmer service is
inoperative, use a DRBIIItscan tool to diagnose the
problem. Refer to the appropriate diagnostic proce-
dures. Refer to the appropriate wiring information.
The wiring 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.
NOTE: Certain indicators in this instrument cluster
are programmable. This feature allows those indica-
tors to be activated or deactivated with a DRBIIIT
scan tool for compatibility with certain optional
equipment. If the problem being diagnosed involves
improper illumination of the upshift indicator, use a
DRBIIITscan tool to be certain that the instrument
cluster has been programmed with the proper vehi-
cle equipment option settings.
PRELIMINARY DIAGNOSIS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.(1) If the indicators operate, but none of the
gauges operate, go to Step 2. If all of the gauges and
the CCD data bus message-controlled indicators are
inoperative, go to Step 5.
(2) Check the fused B(+) fuse (Fuse 14 - 10
ampere) in the Junction Block (JB). If OK, go to Step
3. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(3) Check for battery voltage at the fused B(+) fuse
(Fuse 14 - 10 ampere) in the JB. If OK, go to Step 4.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(4) Disconnect and isolate the battery negative
cable. Remove the instrument cluster. Connect the
battery negative cable. Check for battery voltage at
the fused B(+) circuit cavity of the instrument panel
wire harness connector (Connector C1) for the instru-
ment cluster. If OK, refer to ACTUATOR TEST . If
not OK, repair the open fused B(+) circuit between
the instrument cluster and the JB as required.
(5) Check the fused ignition switch output (st-run)
fuse (Fuse 17 - 10 ampere) in the JB. If OK, go to
Step 6. If not OK, repair the shorted circuit or com-
ponent as required and replace the faulty fuse.
(6) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) fuse (Fuse 17 - 10 ampere) in the JB.
If OK, go to Step 7. If not OK, repair the open fused
ignition switch output (st-run) circuit between the
instrument cluster and the JB as required.
(7) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Reinstall the instrument cluster. Reconnect the bat-
tery negative cable. Turn the ignition switch to the
On position. Set the park brake. The brake indicator
in the instrument cluster should light. If OK, go to
Step 8. If not OK, go to Step 9.
(8) Turn the ignition switch to the Off position.
Turn on the park lamps and adjust the panel lamps
dimmer thumbwheel in the headlamp switch to the
full bright position. The cluster illumination lamps
should light. If OK, go to Step 10. If not OK, repair
the open ground circuit (Z3) between the instrument
cluster and ground (G201) as required.
(9) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the instrument cluster. Connect the battery
negative cable. Turn the ignition switch to the On
position. Check for battery voltage at the fused igni-
tion switch output (st-run) circuit cavity of the
instrument panel wire harness connector (Connector
C1). If OK, refer to ACTUATOR TEST . If not OK,
repair the open fused ignition switch output (st-run)
circuit between the instrument cluster and the JB as
required.
8J - 6 INSTRUMENT CLUSTERBR/BE
INSTRUMENT CLUSTER (Continued)