2001 DODGE RAM ABS

filled coils. The rear coil pack contains two indepen-
dent epoxy filled coils.
OPERATION - 3.9L/5.2L/5.9L
The Powertrain Control Module (PCM) opens and
closes the ignition coil ground circuit for ignition coil
operation.
Battery voltage is supplied to the ignition coil pos-
itive terminal from the ASD relay. If the PCM does
not see a signal from the crankshaft and camshaft
sensors (indicating the ignition key is ON but the
engine is not running), it will shut down the ASD cir-
cuit.
Base ignition timing is not adjustable on any
engine.By controlling the coil ground circuit, the
PCM is able to set the base timing and adjust the
ignition timing advance. This is done to meet chang-
ing engine operating conditions.
OPERATION - 8.0L
When one of the 5 independent coils discharges, it
fires two paired cylinders at the same time (one cyl-
inder on compression stroke and the other cylinder
on exhaust stroke).
Coil firing is paired together on cylinders:
²Number 5 and 10
²Number 9 and 8
²Number 1 and 6
²Number 7 and 4
²Number 3 and 2
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
Battery voltage is supplied to all of the ignition
coils positive terminals from the ASD relay. If the
PCM does not see a signal from the crankshaft and
camshaft sensors (indicating the ignition key is ONbut the engine is not running), it will shut down the
ASD circuit.
Base ignition timing is not adjustable on the
8.0L V-10 engine.By controlling the coil ground cir-
cuit, the PCM is able to set the base timing and
adjust the ignition timing advance. This is done to
meet changing engine operating conditions.
The PCM adjusts ignition timing based on inputs it
receives from:
²The engine coolant temperature sensor
²The crankshaft position sensor (engine speed)
²The manifold absolute pressure (MAP) sensor
²The throttle position sensor
²Transmission gear selection
REMOVAL - 3.9L/5.2L/5.9L
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
3.9L V-6 or 5.2/5.9L V-8 LDC-Gas Engines: The coil
is mounted to a bracket that is bolted to the front of
the right engine cylinder head (Fig. 25). This bracket
is mounted on top of the automatic belt tensioner
bracket using common bolts.
5.9L V-8 HDC-Gas Engine: The coil is mounted to
a bracket that is bolted to the air injection pump
(AIR pump) mounting bracket (Fig. 26).
(1) Disconnect the primary wiring from the igni-
tion coil.
(2) Disconnect the secondary spark plug cable from
the ignition coil.
Fig. 24 Ignition Coil PacksÐ8.0L V-10 Engine
Fig. 25 Ignition CoilÐ3.9L V-6 or 5.2/5.9L V-8
LDC-Gas Engines
1 - ACCESSORY DRIVE BELT TENSIONER
2 - COIL CONNECTOR
3 - IGNITION COIL
4 - COIL MOUNTING BOLTS
8I - 14 IGNITION CONTROLBR/BE
IGNITION COIL (Continued)

INSTRUMENT CLUSTER
TABLE OF CONTENTS
page page
INSTRUMENT CLUSTER
DESCRIPTION............................2
OPERATION.............................3
DIAGNOSIS AND TESTING..................6
INSTRUMENT CLUSTER..................6
REMOVAL..............................10
DISASSEMBLY...........................11
ASSEMBLY.............................13
INSTALLATION...........................14
ABS INDICATOR
DESCRIPTION...........................14
OPERATION.............................14
AIRBAG INDICATOR
DESCRIPTION...........................15
OPERATION.............................15
BRAKE/PARK BRAKE INDICATOR
DESCRIPTION...........................16
OPERATION.............................16
DIAGNOSIS AND TESTING.................16
BRAKE INDICATOR.....................16
CHECK GAUGES INDICATOR
DESCRIPTION...........................17
OPERATION.............................17
CRUISE INDICATOR
DESCRIPTION...........................18
OPERATION.............................18
ENGINE TEMPERATURE GAUGE
DESCRIPTION...........................19
OPERATION.............................19
FUEL GAUGE
DESCRIPTION...........................20
OPERATION.............................20
GEAR SELECTOR INDICATOR
DESCRIPTION...........................21
OPERATION.............................21
HIGH BEAM INDICATOR
DESCRIPTION...........................21
OPERATION.............................22
DIAGNOSIS AND TESTING.................22
HIGH BEAM INDICATOR.................22
LOW FUEL INDICATOR
DESCRIPTION...........................23
OPERATION.............................23
MALFUNCTION INDICATOR LAMP (MIL)
DESCRIPTION...........................24
OPERATION.............................24
ODOMETER
DESCRIPTION...........................24
OPERATION.............................25OIL PRESSURE GAUGE
DESCRIPTION...........................25
OPERATION.............................26
OVERDRIVE OFF INDICATOR
DESCRIPTION...........................27
OPERATION.............................27
SEATBELT INDICATOR
DESCRIPTION...........................27
OPERATION.............................27
SERVICE REMINDER INDICATOR
DESCRIPTION...........................28
OPERATION.............................28
SHIFT INDICATOR (TRANSFER CASE)
DESCRIPTION...........................29
OPERATION.............................29
DIAGNOSIS AND TESTING.................29
FOUR-WHEEL DRIVE INDICATOR..........29
SPEEDOMETER
DESCRIPTION...........................30
OPERATION.............................30
TACHOMETER
DESCRIPTION...........................30
OPERATION.............................31
TRANSMISSION OVERTEMP INDICATOR
DESCRIPTION...........................31
OPERATION.............................31
TURN SIGNAL INDICATORS
DESCRIPTION...........................32
OPERATION.............................32
DIAGNOSIS AND TESTING.................32
TURN SIGNAL INDICATORS..............32
UPSHIFT INDICATOR
DESCRIPTION...........................33
OPERATION.............................33
VOLTAGE GAUGE
DESCRIPTION...........................33
OPERATION.............................34
WAIT-TO-START INDICATOR
DESCRIPTION...........................34
OPERATION.............................35
WASHER FLUID INDICATOR
DESCRIPTION...........................35
OPERATION.............................35
DIAGNOSIS AND TESTING.................36
WASHER FLUID INDICATOR..............36
WATER-IN-FUEL INDICATOR
DESCRIPTION...........................36
OPERATION.............................37
BR/BEINSTRUMENT CLUSTER 8J - 1

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 - OVERLAY AND GAUGES
4 - HOOD
5 - LENS
6 - CIRCUIT BOARD
7 - ODOMETER SWITCH BUTTON
8J - 2 INSTRUMENT CLUSTERBR/BE

INSTRUMENT CLUSTER FAILURE MESSAGE
Message Description Correction
110 A failure has been identified in the cluster
CPU, RAM, or EEPROM.1. Replace the faulty cluster.
900 The CCD data bus is not operational. 1. Check the CCD data bus connections at the
cluster.
2. Check the cluster fuses.
3. Check the CCD data bus bias.
4. Check the CCD data bus voltage.
5. Check the CCD data bus terminations.
920 The cluster is not receiving a vehicle speed
message from the PCM.1. Check the PCM software level and reflash if
required.
2. Use a DRBIIITscan tool to verify that the
vehicle speed message is being sent by the
PCM.
921 The cluster is not receiving a distance pulse
message from the PCM.1. Check the PCM software level and reflash if
required.
2. Use a DRBIIITscan tool to verify that the
distance pulse message is being sent by the
PCM.
940 The cluster is not receiving an airbag lamp-on
message from the ACM.1. Check the CCD data bus connections at the
ACM.
2. Check the ACM fuse.
950 The cluster is not receiving an ABS lamp-on
message from the CAB.1. Check the CCD data bus connections at the
CAB.
2. Check the CAB fuse.
999 An error has been discovered. 1. Record the failure message.
2. Depress the trip odometer reset button to
continue the Self-Diagnostic Test.
(6) The instrument cluster will begin the Vacuum
Fluorescent Display (VFD) walking segment test.
This test will require the operator to visually inspect
each VFD segment as it is displayed to determine a
pass or fail condition. First, all of the segments will
be illuminated at once; then, each individual segment
of the VFD will be illuminated in sequence. If any
segment in the display fails to illuminate, repeat the
test to confirm the failure. If the failure is confirmed,
replace the faulty instrument cluster. Following com-
pletion of the VFD walking segment test, the actua-
tor test will proceed as described in Step 7.
(7) The instrument cluster will perform a bulb
check of each indicator that the instrument cluster
circuitry controls. If the wait-to-start indicator does
not illuminate during this test, the instrument clus-
ter should be removed. However, check that the
incandescent bulb is not faulty and that the bulb
holder is properly installed on the instrument cluster
electronic circuit board before considering instrument
cluster replacement. If the bulb and bulb holder
check OK, replace the faulty instrument cluster.
Each of the remaining instrument cluster circuitrycontrolled indicators except the cruise indicator are
illuminated by a Light Emitting Diode (LED). If an
LED or the cruise indicator in the VFD, fails to illu-
minate during this test, the instrument cluster must
be replaced. Following the bulb check test, the actua-
tor test will proceed as described in Step 8.
(8) The instrument cluster will perform a gauge
actuator test. In this test the instrument cluster cir-
cuitry positions each of the gauge needles at three
different calibration points, then returns the gauge
needles to their relaxed positions. If an individual
gauge does not respond properly, or does not respond
at all during the gauge actuator test, the instrument
cluster should be removed. However, check that the
gauge terminal pins are properly inserted through
the spring-clip terminal pin receptacles on the instru-
ment cluster electronic circuit board before consider-
ing instrument cluster replacement. If the gauge
terminal connections are OK, replace the faulty
instrument cluster.
(9) The actuator test is now completed. The instru-
ment cluster will automatically exit the self-diagnos-
tic mode and return to normal operation at the
8J - 8 INSTRUMENT CLUSTERBR/BE
INSTRUMENT CLUSTER (Continued)

DISASSEMBLY
Some of the components for the instrument cluster
used in this vehicle are serviced individually. The
serviced components include: the automatic transmis-
sion gear selector indicator, the incandescent instru-
ment cluster indicator lamp and illumination lamp
bulbs (including the integral bulb holders), the clus-
ter lens and hood unit, and the cluster housing rear
cover. The remaining components are serviced only
as a part of the cluster housing unit, which includes:
the cluster housing, the electronic circuit board unit,
the cluster overlay, the gauges, and the odometer/trip
odometer reset switch button. Following are the pro-
cedures for disassembling the serviced components
from the instrument cluster unit.
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.GEAR SELECTOR INDICATOR
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
(3) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(4) Reach through the instrument panel steering
column opening to access and disengage the loop end
of the gear selector indicator cable from the PRNDL
driver lever on the left side of the steering column
(Fig. 4).
(5) Squeeze the sides of the plastic adjuster and
bracket unit to disengage the tabs that secure it to
the sides of the steering column window.
(6) Remove the gear selector indicator mechanism
and cable unit through the instrument panel cluster
opening.
CLUSTER BULB
This procedure applies to each of the incandescent
cluster illumination lamp or indicator lamp bulb and
bulb holder units. However, the illumination lamps
and the indicator lamps use different bulb and bulb
holder unit sizes. They must never be interchanged.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument cluster from the instru-
ment panel. (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - REMOVAL).
Fig. 3 Gear Selector Indicator Remove/Install
1 - INSTRUMENT CLUSTER
2 - GEAR SELECTOR INDICATOR
3 - SCREW
Fig. 4 Gear Selector Indicator Cable Remove/Install
1 - STEERING COLUMN
2 - CABLE
3 - LOOP END
4 - LEVER
5 - ADJUSTER AND BRACKET
BR/BEINSTRUMENT CLUSTER 8J - 11
INSTRUMENT CLUSTER (Continued)

ASSEMBLY
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.
GEAR SELECTOR INDICATOR
(1) Position the gear selector indicator mechanism
and cable unit into the instrument panel cluster
opening.
(2) Route the cable through the instrument panel
and under the steering column to the PRNDL driver
lever on the left side of the steering column.
(3) Squeeze the sides of the plastic adjuster and
bracket unit and engage the tabs that secure it with
the sides of the steering column window.
(4) Engage the loop end of the gear selector indi-
cator cable onto the PRNDL driver lever on the left
side of the steering column (Fig. 4).
(5) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(6) Confirm proper operation of the gear selector
indicator. Calibrate the indicator, if required. (Refer
to 19 - STEERING/COLUMN - INSTALLATION).
(7) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(8) Reconnect the battery negative cable.
CLUSTER BULB
This procedure applies to each of the incandescent
cluster illumination lamp or indicator lamp bulb and
bulb holder units. However, the illumination lamps
and the indicator lamps use different bulb and bulb
holder unit sizes. They must never be interchanged.
CAUTION: Be certain that any bulb and bulb holder
unit removed from the cluster electronic circuit
board is reinstalled in the correct position. Always
use the correct bulb size and type for replacement.
An incorrect bulb size or type may overheat and
cause damage to the instrument cluster, the elec-
tronic circuit board and/or the gauges.(1) Insert the bulb and bulb holder unit straight
into the correct bulb mounting hole in the cluster
electronic circuit board (Fig. 5).
(2) With the bulb holder fully seated against the
cluster electronic circuit board, turn the bulb holder
clockwise about sixty degrees to lock it into place.
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
CLUSTER LENS AND HOOD
CAUTION: Do not touch the face of the gauge over-
lay or the back of the cluster lens with your finger.
It will leave a permanent finger print.
(1) Align the cluster lens and hood unit with the
cluster housing. Be certain that the odometer/trip
odometer switch button is installed through the
clearance hole in the lens (Fig. 6).
(2) Install and tighten the seven screws that
secure the lens and hood unit to the cluster housing.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
CLUSTER HOUSING REAR COVER
(1) Position the rear cover onto the back of the
cluster housing (Fig. 7).
(2) Install and tighten the six screws that secure
the rear cover to the back of the cluster housing.
Tighten the screws to 2.2 N´m (20 in. lbs.).
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
CLUSTER HOUSING
(1) Assemble the rear cover onto the cluster hous-
ing. Refer to CLUSTER HOUSING REAR COVER .
(2) Assemble the lens and hood unit onto the clus-
ter housing. Refer to CLUSTER LENS AND HOOD .
(3) Reinstall the instrument cluster onto the
instrument panel. (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - INSTALLATION).
(4) Reconnect the battery negative cable.
BR/BEINSTRUMENT CLUSTER 8J - 13
INSTRUMENT CLUSTER (Continued)

INSTALLATION
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) Position the instrument cluster to the instru-
ment panel.
(2) If the vehicle is equipped with an automatic
transmission, position the gear selector indicator onto
the back of the cluster housing (Fig. 3).
(3) If the vehicle is equipped with an automatic
transmission, install and tighten the two screws that
secure the gear selector indicator mechanism to the
back of the cluster housing. Tighten the screws to 2.2
N´m (20 in. lbs.).
(4) Align the instrument cluster with the cluster
opening in the instrument panel and push the cluster
firmly and evenly into place. The instrument panel
wire harness has two self-docking connectors that
will be automatically aligned with, and connected to
the instrument cluster connector receptacles when
the cluster is properly installed in the instrument
panel.
(5) Install and tighten the four screws that secure
the instrument cluster to the instrument panel (Fig.
2). Tighten the screws to 2.2 N´m (20 in. lbs.).
(6) Reinstall the cluster bezel onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(7) If the vehicle is equipped with an automatic
transmission, confirm proper operation of the gear
selector indicator. Calibrate the indicator, if required.
(Refer to 19 - STEERING/COLUMN - INSTALLA-
TION).
(8) Reconnect the battery negative cable.
NOTE: Some of the indicators in this instrument
cluster are either programmable (upshift indicator)
or automatically configured (cruise, overdrive-off,
and transmission overtemp indicators) when the
cluster is connected to the vehicle electrical sys-
tem. This feature allows those indicator lamps to be
enabled or disabled for compatibility with certain
optional equipment. If a new instrument cluster is
being installed, use a DRBIIITscan tool to programthe instrument cluster with the proper vehicle
equipment option setting to enable and/or disable
the upshift indicator lamp. Refer to the appropriate
diagnostic information.
ABS INDICATOR
DESCRIPTION
An Antilock Brake System (ABS) indicator is stan-
dard equipment on all instrument clusters. This indi-
cator serves both the standard equipment Rear
Wheel Anti-Lock (RWAL) and optional equipment
4-Wheel Anti-Lock (4WAL) brake systems. The ABS
indicator is located near the lower edge of the instru-
ment cluster overlay, to the left of center. The ABS
indicator consists of a stencilled cutout of the Inter-
national Control and Display Symbol icon for ªFail-
ure of Anti-lock Braking Systemº in the opaque layer
of the instrument cluster overlay. The dark outer
layer of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
overlay causes the icon to appear in amber through
the translucent outer layer of the overlay when it is
illuminated from behind by a Light Emitting Diode
(LED) soldered onto the instrument cluster electronic
circuit board. The ABS indicator is serviced as a unit
with the instrument cluster.
OPERATION
The ABS indicator gives an indication to the vehi-
cle operator when the ABS system is faulty or inop-
erative. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon clus-
ter programming and electronic messages received by
the cluster from the Controller Antilock Brake (CAB)
over the Chrysler Collision Detection (CCD) data bus.
The ABS indicator Light Emitting Diode (LED)
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (st-run) circuit whenever the ignition
switch is in the On or Start positions; therefore, the
LED will always be off when the ignition switch is in
any position except On or Start. The LED only illu-
minates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the ABS indicator for the following rea-
sons:
²Bulb Test- Each time the ignition switch is
turned to the On position the ABS indicator is illu-
minated by the cluster for about two seconds as a
bulb test.
²ABS Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the CAB, the
8J - 14 INSTRUMENT CLUSTERBR/BE
INSTRUMENT CLUSTER (Continued)

ABS indicator will be illuminated. The indicator
remains illuminated until the cluster receives a
lamp-off message from the CAB, or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Communication Error- If the cluster receives
no lamp-on or lamp-off messages from the CAB for
six consecutive seconds, the ABS indicator is illumi-
nated. The indicator remains illuminated until the
cluster receives a valid message from the CAB, 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 ABS indica-
tor will be turned on during the bulb check portion of
the test to confirm the functionality of the LED and
the cluster control circuitry.
²ABS Diagnostic Test- The ABS indicator is
blinked on and off by lamp-on and lamp-off messages
from the CAB during the performance of the ABS
diagnostic tests.
The CAB continually monitors the ABS circuits
and sensors to decide whether the system is in good
operating condition. The CAB then sends the proper
lamp-on or lamp-off messages to the instrument clus-
ter. If the CAB sends a lamp-on message after the
bulb test, it indicates that the CAB has detected a
system malfunction and/or that the ABS system has
become inoperative. The CAB will store a Diagnostic
Trouble Code (DTC) for any malfunction it detects.
Each time the ABS indicator fails to light due to an
open or short in the cluster ABS indicator circuit, the
cluster sends a message notifying the CAB of the
condition, and the CAB will store a DTC. For proper
diagnosis of the antilock brake system, the CAB, the
CCD data bus, or the message inputs to the instru-
ment cluster that control the ABS indicator, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
AIRBAG INDICATOR
DESCRIPTION
An airbag indicator is standard equipment on all
instrument clusters. However, on vehicles not
equipped with airbags, this indicator is electronically
disabled. The airbag indicator is located near the
lower edge of the instrument cluster overlay, to the
right of center. The airbag indicator consists of a
stenciled cutout of the word ªAIRBAGº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. A red
lens behind the cutout in the opaque layer of the
overlay causes the ªAIRBAGº text to appear in redthrough the translucent outer layer of the overlay
when it is illuminated from behind by a Light Emit-
ting Diode (LED) soldered onto the instrument clus-
ter electronic circuit board. The airbag indicator is
serviced as a unit with the instrument cluster.
OPERATION
The airbag indicator gives an indication to the
vehicle operator when the airbag system is faulty or
inoperative. The airbag indicator is controlled by a
transistor on the instrument cluster circuit board
based upon cluster programming and electronic mes-
sages received by the cluster from the Airbag Control
Module (ACM) over the Chrysler Collision Detection
(CCD) data bus. The airbag indicator Light Emitting
Diode (LED) receives battery current on the instru-
ment cluster electronic circuit board through the
fused ignition switch output (st-run) circuit whenever
the ignition switch is in the On or Start positions;
therefore, the indicator will always be off when the
ignition switch is in any position except On or Start.
The LED only illuminates when it is provided a path
to ground by the instrument cluster transistor. The
instrument cluster will turn on the airbag indicator
for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the airbag indicator is illu-
minated for about seven seconds. The first two sec-
onds is the cluster bulb test function, and the
remainder is the ACM bulb test function.
²ACM Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the ACM, the
airbag indicator will be illuminated. The indicator
remains illuminated for about twelve seconds or until
the cluster receives a lamp-off message from the
ACM, whichever is longer.
²Communication Error- If the cluster receives
no airbag messages for three consecutive seconds, the
airbag indicator is illuminated. The indicator
remains illuminated for about twelve seconds or until
the cluster receives a single lamp-off message from
the ACM, whichever is longer.
²Actuator Test- Each time the cluster is put
through the actuator test, the airbag indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The ACM continually monitors the airbag system
circuits and sensors to decide whether the system is
in good operating condition. The ACM then sends the
proper lamp-on or lamp-off messages to the instru-
ment cluster. If the ACM sends a lamp-on message
after the bulb test, it indicates that the ACM has
detected a system malfunction and/or that the air-
bags may not deploy when required, or may deploy
when not required. The ACM will store a Diagnostic
BR/BEINSTRUMENT CLUSTER 8J - 15
ABS INDICATOR (Continued)