1998 DODGE RAM 1500 Security

GROUP TAB LOCATOR
Introduction
0Lubrication & Maintenance
2Suspension
3Differential & Driveline
5Brakes
6Clutch
7Cooling
8AAudio/Video
8BChime/Buzzer
8EElectronic Control Modules
8FEngine Systems
8GHeated Systems
8HHorn
8IIgnition Control
8JInstrument Cluster
8LLamps
8MMessage Systems
8NPower Systems
8ORestraints
8PSpeed Control
8QVehicle Theft Security
8RWipers/Washers
8TNavigation/Telecommunication
8WWiring
9Engine
11Exhaust System
13Frame & Bumpers
14Fuel System
19Steering
21Transmission and Transfer Case
22Tires/Wheels
23Body
24Heating & Air Conditioning
25Emissions Control
Component and System Index
Service Manual Comment Forms (Rear of Manual)

(8) If the previous step is not performed, a Diag-
nostic Trouble Code (DTC) will be set.
(9) If necessary, use DRB IIItScan Tool to erase
any Diagnostic Trouble Codes (DTC's) from PCM.
Also use the DRB scan tool to reprogram new PCM
with vehicles original Vehicle Identification Number
(VIN) and original vehicle mileage.
SENTRY KEY IMMOBILIZER
MODULE
DESCRIPTION
The Sentry Key Immobilizer Module (SKIM) con-
tains a Radio Frequency (RF) transceiver and a cen-
tral processing unit, which includes the Sentry Key
Immobilizer System (SKIS) program logic. The SKIS
programming enables the SKIM to program and
retain in memory the codes of at least two, but no
more than eight electronically coded Sentry Key
transponders. The SKIS programming also enables
the SKIM to communicate over the Programmable
Communication Interface (PCI) bus network with the
Powertrain Control Module (PCM) or Electronic Con-
trol Module (ECM), depending on engine application,
and/or the DRBIIItscan tool.
OPERATION
The SKIM transmits and receives RF signals
through a tuned antenna enclosed within a molded
plastic ring that is integral to the SKIM housing.
When the SKIM is properly installed on the steering
column, the antenna ring is oriented around the igni-
tion lock cylinder housing. This antenna ring must be
located within eight millimeters (0.31 inches) of the
Sentry Key in order to ensure proper RF communica-
tion between the SKIM and the Sentry Key tran-
sponder.
For added system security, each SKIM is pro-
grammed with a unique ªSecret Keyº code and a
security code. The SKIM keeps the ªSecret Keyº code
in memory. The SKIM also sends the ªSecret Keyº
code to each of the programmed Sentry Key tran-
sponders. The security code is used by the assembly
plant to access the SKIS for initialization, or by the
dealer technician to access the system for service.
The SKIM also stores in its memory the Vehicle
Identification Number (VIN), which it learns through
a PCI bus message from the PCM (NGC) or ECM
(Cummins) during initialization.The SKIM and the PCM/ECM both use software
that includes a rolling code algorithm strategy, which
helps to reduce the possibility of unauthorized SKIS
disarming. The rolling code algorithm ensures secu-
rity by preventing an override of the SKIS through
the unauthorized substitution of the SKIM or the
PCM/ECM. However, the use of this strategy also
means that replacement of either the SKIM or the
PCM/ECM units will require a system initialization
procedure to restore system operation.
When the ignition switch is turned to the ON or
START positions, the SKIM transmits an RF signal
to excite the Sentry Key transponder. The SKIM then
listens for a return RF signal from the transponder
of the Sentry Key that is inserted in the ignition lock
cylinder. If the SKIM receives an RF signal with
valid ªSecret Keyº and transponder identification
codes, the SKIM sends a ªvalid keyº message to the
PCM/ECM over the PCI bus. If the SKIM receives an
invalid RF signal or no response, it sends ªinvalid
keyº messages to the PCM/ECM. The PCM/ECM will
enable or disable engine operation based upon the
status of the SKIM messages.
The SKIM also sends messages to the Instrument
Cluster which controls the VTSS indicator LED. The
SKIM sends messages to the Instrument Cluster to
turn the LED on for about three seconds when the
ignition switch is turned to the ON position as a bulb
test. After completion of the bulb test, the SKIM
sends bus messages to keep the LED off for a dura-
tion of about one second. Then the SKIM sends mes-
sages to turn the LED on or off based upon the
results of the SKIS self-tests. If the VTSS indicator
LED comes on and stays on after the bulb test, it
indicates that the SKIM has detected a system mal-
function and/or that the SKIS has become inopera-
tive.
If the SKIM detects an invalid key when the igni-
tion switch is turned to the ON position, it sends
messages to flash the VTSS indicator LED. The
SKIM can also send messages to flash the LED as an
indication to the customer that the SKIS has been
placed in it's ªCustomer Learnº programming mode.
See Sentry Key Immobilizer System Transponder
Programming in this section for more information on
the ªCustomer Learnº programming mode.
For diagnosis or initialization of the SKIM and the
PCM/ECM, a DRBIIItscan tool and the proper Pow-
ertrain Diagnostic Procedures manual are required.
The SKIM cannot be repaired and, if faulty or dam-
aged, the unit must be replaced.
DRELECTRONIC CONTROL MODULES 8E - 13
POWERTRAIN CONTROL MODULE (Continued)

INSTRUMENT CLUSTER
TABLE OF CONTENTS
page page
INSTRUMENT CLUSTER
DESCRIPTION..........................2
OPERATION............................6
DIAGNOSIS AND TESTING - INSTRUMENT
CLUSTER...........................10
REMOVAL.............................14
DISASSEMBLY.........................14
ASSEMBLY............................15
INSTALLATION.........................16
ABS INDICATOR
DESCRIPTION.........................17
OPERATION...........................17
AIRBAG INDICATOR
DESCRIPTION.........................18
OPERATION...........................18
BRAKE/PARK BRAKE INDICATOR
DESCRIPTION.........................19
OPERATION...........................19
DIAGNOSIS AND TESTING - BRAKE
INDICATOR..........................20
CARGO LAMP INDICATOR
DESCRIPTION.........................20
OPERATION...........................20
CHECK GAUGES INDICATOR
DESCRIPTION.........................21
OPERATION...........................21
CRUISE INDICATOR
DESCRIPTION.........................22
OPERATION...........................22
DOOR AJAR INDICATOR
DESCRIPTION.........................23
OPERATION...........................23
ENGINE TEMPERATURE GAUGE
DESCRIPTION.........................24
OPERATION...........................24
ETC INDICATOR
DESCRIPTION.........................25
OPERATION...........................25
FUEL GAUGE
DESCRIPTION.........................26
OPERATION...........................26
GEAR SELECTOR INDICATOR
DESCRIPTION.........................27
OPERATION...........................27
HIGH BEAM INDICATOR
DESCRIPTION.........................28
OPERATION...........................28
LAMP OUT INDICATOR
DESCRIPTION.........................29OPERATION...........................29
LOW FUEL INDICATOR
DESCRIPTION.........................30
OPERATION...........................30
MALFUNCTION INDICATOR LAMP (MIL)
DESCRIPTION.........................31
OPERATION...........................31
ODOMETER
DESCRIPTION.........................32
OPERATION...........................32
OIL PRESSURE GAUGE
DESCRIPTION.........................33
OPERATION...........................33
SEATBELT INDICATOR
DESCRIPTION.........................34
OPERATION...........................34
STANDARD PROCEDURE - ENHANCED
SEATBELT REMINDER PROGRAMMING....35
SECURITY INDICATOR
DESCRIPTION.........................35
OPERATION...........................36
SERVICE 4WD INDICATOR
DESCRIPTION.........................36
OPERATION...........................37
SPEEDOMETER
DESCRIPTION.........................37
OPERATION...........................37
TACHOMETER
DESCRIPTION.........................38
OPERATION...........................38
TOW/HAUL INDICATOR
DESCRIPTION.........................39
OPERATION...........................39
TRANS TEMP INDICATOR
DESCRIPTION.........................40
OPERATION...........................40
TURN SIGNAL INDICATOR
DESCRIPTION.........................40
OPERATION...........................41
UPSHIFT INDICATOR
DESCRIPTION.........................41
OPERATION...........................42
VOLTAGE GAUGE
DESCRIPTION.........................42
OPERATION...........................43
WAIT-TO-START INDICATOR
DESCRIPTION.........................44
OPERATION...........................44
DRINSTRUMENT CLUSTER 8J - 1

Sandwiched between the rear cover and the lens,
hood and mask unit is the cluster housing. The
molded plastic cluster housing serves as the carrier
for the cluster circuit board and circuitry, the cluster
connector receptacles, the RKE interface connector,
the gauges, a Light Emitting Diode (LED) for each
cluster indicator, two VFD units, an audible tone
generator, the cluster overlay, the gauge pointers, the
odometer/trip odometer switch and the switch button.
The cluster overlay is a laminated plastic unit. The
dark, visible, outer surface of the overlay is marked
with all of the gauge dial faces and graduations, but
this layer is also translucent. The darkness of this
outer layer prevents the cluster from appearing clut-
tered or busy by concealing the cluster indicators
that are not illuminated, while the translucence of
this layer allows those indicators and icons that are
illuminated to be readily visible. The underlying
layer of the overlay is opaque and allows light from
the LED for each of the various indicators and the
incandescent illumination lamps behind it to be visi-
ble through the outer layer of the overlay only
through predetermined stencil-like cutouts. A rectan-
gular opening in the overlay at the base of both the
speedometer and tachometer dial faces has a smoked
clear lens through which the illuminated VFD units
can be viewed.
Several versions of the EMIC module are offered
on this model. These versions accommodate all of the
variations of optional equipment and regulatory
requirements for the various markets in which the
vehicle will be offered. The microprocessor-based
EMIC utilizes integrated circuitry and information
carried on the Programmable Communications Inter-
face (PCI) data bus network along with several hard
wired analog and multiplexed inputs to monitor sen-
sors and switches throughout the vehicle. In response
to those inputs, the internal circuitry and program-
ming of the EMIC allow it to control and integrate
many electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus. (Refer
to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/COMMUNICATION - DESCRIPTION -
PCI BUS).
Besides typical instrument cluster gauge and indi-
cator support, the electronic functions and features
that the EMIC supports or controls include the fol-
lowing:
²Audible Warnings- The EMIC electronic cir-
cuit board is equipped with an audible tone generator
and programming that allows it to provide various
audible alerts to the vehicle operator, including
chime tones and beep tones. An electromechanical
relay is also soldered onto the circuit board to pro-duce audible clicks that emulate the sound of a con-
ventional turn signal or hazard warning flasher.
(Refer to 8 - ELECTRICAL/CHIME/BUZZER -
DESCRIPTION).
²Brake Lamp Control- The EMIC provides
electronic brake lamp request messages to the Front
Control Module (FCM) located on the Integrated
Power Module (IPM) for brake lamp control, exclud-
ing control of the Center High Mounted Stop Lamp
(CHMSL), which remains controlled by a direct hard
wired output of the brake lamp switch.
²Brake Transmission Shift Interlock Control
- The EMIC monitors inputs from the brake lamp
switch, ignition switch, and the Transmission Range
Sensor (TRS), then controls a high-side driver output
to operate the Brake Transmission Shift Interlock
(BTSI) solenoid that locks and unlocks the automatic
transmission gearshift selector lever on the steering
column.
²Cargo Lamp Control- The EMIC provides
direct control of cargo lamp operation with a load
shedding (battery saver) feature which will automat-
ically turn off the cargo lamp if it remains on after a
timed interval.
²Central Locking- The EMIC provides support
for the central locking feature of the power lock sys-
tem. This feature will lock or unlock all doors based
upon the input from the door cylinder lock switch.
Door cylinder lock switches are used only on models
equipped with the optional Vehicle Theft Security
System (VTSS).
²Door Lock Inhibit- The EMIC inhibits locking
of the doors with the power lock switch when the key
is in the ignition switch and the driver side front
door is ajar. However, operation of the door locks is
not inhibited under the same conditions when the
Lock button of the optional RKE transmitter is
depressed.
²Enhanced Accident Response- The EMIC
monitors an input from the Airbag Control Module
(ACM) and, following an airbag deployment, will
immediately disable the power lock output, unlock all
doors by activating the power unlock output, then
enables the power lock output. This feature, like all
other enhanced accident response features, is depen-
dent upon a functional vehicle electrical system fol-
lowing the vehicle impact event.
²Exterior Lighting Control- The EMIC pro-
vides electronic head lamp and/or park lamp request
messages to the Front Control Module (FCM) located
on the Integrated Power Module (IPM) for the appro-
priate exterior lamp control of standard head and
park lamps, as well as optional front fog lamps. This
includes support for headlamp beam selection and
the optical horn feature, also known as flash-to-pass.
DRINSTRUMENT CLUSTER 8J - 3
INSTRUMENT CLUSTER (Continued)

²Exterior Lighting Fail-safe- In the absence of
a headlamp switch input, the EMIC will turn on the
cluster illumination lamps and provide electronic
headlamp low beam and park lamp request messages
to the Front Control Module (FCM) located on the
Integrated Power Module (IPM) for default exterior
lamp operation. The FCM will also provide default
park lamp and headlamp low beam operation and the
EMIC will turn on the cluster illumination lamps if
there is a failure of the electronic data bus commu-
nication between the EMIC and the FCM.
²Heated Seat Control- The EMIC monitors
inputs from the ignition switch and electronic engine
speed messages from the Powertrain Control Module
(PCM) to control a high side driver output to the
heated seat switch Light Emitting Diode (LED) indi-
cators. This input allows the heated seat switches to
wake up the heated seat module if the switch is actu-
ated. The EMIC will de-energize the heated seat
switch LED indicators, which deactivates the heated
seat system, if the ignition switch is turned to any
position except On or Start, or if the engine speed
message indicates zero. (Refer to 8 - ELECTRICAL/
HEATED SEATS - DESCRIPTION).
²Interior Lamp Load Shedding- The EMIC
provides a battery saver feature which will automat-
ically turn off all interior lamps that remain on after
a timed interval of about fifteen minutes.
²Interior Lamps - Enhanced Accident
Response- The EMIC monitors inputs from the Air-
bag Control Module (ACM) and the Powertrain Con-
trol Module (PCM) to automatically turn on the
interior lighting after an airbag deployment event
ten seconds after the vehicle speed is zero. The inte-
rior lighting remains illuminated until the key is
removed from the ignition switch lock cylinder, at
which time the interior lighting returns to normal
operation and control. This feature, like all other
enhanced accident response features, is dependent
upon a functional vehicle electrical system following
the vehicle impact event.
²Interior Lighting Control- The EMIC moni-
tors inputs from the interior lighting switch, the door
ajar switches, the cargo lamp switch, the reading
lamp switches, and the Remote Keyless Entry (RKE)
module to provide courtesy lamp control. This
includes support for timed illuminated entry with
theater-style fade-to-off and courtesy illumination
defeat features.
²Lamp Out Indicator Control- The EMIC
monitors electronic lamp outage messages from the
Front Control Module (FCM) located on the Inte-
grated Power Module (IPM) in order to provide lamp
out indicator control for the headlamps (low and high
beams), turn signal lamps, and the brake lamps
(excluding CHMSL).²Panel Lamps Dimming Control- The EMIC
provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of all hard wired panel lamps dimmer controlled
lamps with that of the cluster illumination lamps.
²Parade Mode- The EMIC provides a parade
mode (also known as funeral mode) that allows all
Vacuum-Fluorescent Display (VFD) units in the vehi-
cle to be illuminated at full (daytime) intensity while
driving during daylight hours with the exterior
lamps turned on.
²Power Locks- The EMIC monitors inputs from
the power lock switches and the Remote Keyless
Entry (RKE) receiver module (optional) to provide
control of the power lock motors through high side
driver outputs to the power lock motors. This
includes support for rolling door locks (also known as
automatic door locks), automatic door unlock, a door
lock inhibit mode, and central locking (with the
optional Vehicle Theft Security System only). (Refer
to 8 - ELECTRICAL/POWER LOCKS - DESCRIP-
TION).
²Remote Keyless Entry- The EMIC supports
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock, Unlock
(with optional driver-door-only unlock, and unlock-
all-doors), Panic, audible chirp, optical chirp, illumi-
nated entry modes, an RKE programming mode, as
well as optional Vehicle Theft Security System
(VTSS) arming (when the proper VTSS arming con-
ditions are met) and disarming.
²Remote Radio Switch Interface- The EMIC
monitors inputs from the optional remote radio
switches and then provides the appropriate electronic
data bus messages to the radio to select the radio
operating mode, volume control, preset station scan
and station seek features.
²Rolling Door Locks- The EMIC provides sup-
port for the power lock system rolling door locks fea-
ture (also known as automatic door locks). This
feature will automatically lock all unlocked doors
each time the vehicle speed reaches twenty-four kilo-
meters-per-hour (fifteen miles-per-hour). Following
an automatic lock event, if the driver side front door
is opened first after the ignition is turned to the Off
position, all doors will be automatically unlocked.
²Turn Signal & Hazard Warning Lamp Con-
trol- The EMIC provides electronic turn and hazard
lamp request messages to the Front Control Module
(FCM) located on the Integrated Power Module (IPM)
for turn and hazard lamp control. The EMIC also
provides an audible click at one of two rates to emu-
late normal and bulb out turn or hazard flasher oper-
ation based upon electronic lamp outage messages
from the FCM, and provides an audible turn signal
on chime warning if a turn is signalled continuously
8J - 4 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

for more than about 1.6 kilometers (one mile) and
the vehicle speed remains greater than about twenty-
four kilometers-per-hour (fifteen miles-per-hour).
²Vacuum Fluorescent Display Synchroniza-
tion- The EMIC transmits electronic panel lamp
dimming level messages which allows all other elec-
tronic modules on the PCI data bus with Vacuum
Fluorescent Display (VFD) units to coordinate their
illumination intensity with that of the EMIC VFD
units.
²Vehicle Theft Security System- The EMIC
monitors inputs from the door cylinder lock
switch(es), the door ajar switches, the ignition
switch, and the Remote Keyless Entry (RKE) receiver
module, then provides electronic horn and lighting
request messages to the Front Control Module (FCM)
located on the Integrated Power Module (IPM) for
the appropriate VTSS alarm output features.
²Wiper/Washer System Control- The EMIC
provides electronic wiper and/or washer request mes-
sages to the Front Control Module (FCM) located on
the Integrated Power Module (IPM) for the appropri-
ate wiper and washer system features. (Refer to 8 -
ELECTRICAL/WIPERS/WASHERS - DESCRIP-
TION).
The EMIC houses six analog gauges and has pro-
visions for up to twenty-three indicators (Fig. 3) or
(Fig. 4). The EMIC includes the following analog
gauges:
²Coolant Temperature Gauge
²Fuel Gauge
²Oil Pressure Gauge
²Speedometer
²Tachometer
²Voltage Gauge
Some of the EMIC indicators are automatically
configured when the EMIC is connected to the vehi-
cle electrical system for compatibility with certain
optional equipment or equipment required for regula-
tory purposes in certain markets. While each EMIC
may have provisions for indicators to support every
available option, the configurable indicators will not
be functional in a vehicle that does not have the
equipment that an indicator supports. The EMIC
includes provisions for the following indicators (Fig.
3) or (Fig. 4):
²Airbag Indicator (with Airbag System only)
²Antilock Brake System (ABS) Indicator
(with ABS or Rear Wheel Anti-Lock [RWAL]
brakes only)
²Brake Indicator
²Cargo Lamp Indicator
²Check Gauges Indicator
²Cruise Indicator (with Speed Control only)
²Door Ajar Indicator²Electronic Throttle Control (ETC) Indicator
(with 5.7L Gasoline Engine only)
²Gear Selector Indicator (with Automatic
Transmission only)
²High Beam Indicator
²Lamp Out Indicator
²Low Fuel Indicator
²Malfunction Indicator Lamp (MIL)
²Seatbelt Indicator
²Security Indicator (with Sentry Key Immo-
bilizer & Vehicle Theft Security Systems only)
²Service Four-Wheel Drive Indicator (with
Four-Wheel Drive only)
²Tow/Haul Indicator (with Automatic Trans-
mission only)
²Transmission Overtemp Indicator (with
Automatic Transmission only)
²Turn Signal (Right and Left) Indicators
²Upshift Indicator (with Manual Transmis-
sion only)
²Washer Fluid Indicator
²Wait-To-Start Indicator (with Diesel Engine
only)
²Water-In-Fuel Indicator (with Diesel Engine
only)
Each indicator in the EMIC, except those located
within one of the VFD units, is illuminated by a ded-
icated LED that is soldered onto the EMIC electronic
circuit board. The LED units are not available for
service replacement and, if damaged or faulty, the
entire EMIC must be replaced. Cluster illumination
is accomplished by dimmable incandescent back
lighting, which illuminates the gauges for visibility
when the exterior lighting is turned on. Each of the
incandescent bulbs is secured by an integral 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, a
VFD unit, the electronic circuit board, the circuit
DRINSTRUMENT CLUSTER 8J - 5
INSTRUMENT CLUSTER (Continued)

board hardware, the cluster overlay, or the EMIC
housing are damaged or faulty, the entire EMIC mod-
ule must be replaced. The cluster lens, hood and
mask unit and the individual incandescent lamp
bulbs with holders are available for individual ser-
vice replacement.
OPERATION
The ElectroMechanical Instrument Cluster (EMIC)
in this model also includes the hardware and soft-
ware necessary to serve as the electronic body control
module and is sometimes referred to as the Cab
Compartment Node or CCN. The following informa-
tion deals primarily with the instrument cluster
functions of this unit. Additional details of the elec-
tronic body control functions of this unit may be
found within the service information for the system
or component that the EMIC controls. For example:
Additional details of the audible warning functions ofthe EMIC are found within the Chime/Buzzer service
information.
The EMIC is designed to allow the vehicle operator
to monitor the conditions of many of the vehicle com-
ponents and operating systems. The gauges and indi-
cators in the EMIC provide valuable information
about the various standard and optional powertrains,
fuel and emissions 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 allow-
ing relative ease of access for service. The micropro-
cessor-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 messages that are transmitted by other
electronic modules over the Programmable Communi-
cations Interface (PCI) data bus network. (Refer to 8
Fig. 3 Gauges & Indicators - Gasoline Engine
1 - MALFUNCTION INDICATOR LAMP 13 - ELECTRONIC THROTTLE CONTROL (ETC) INDICATOR
2 - VOLTAGE GAUGE 14 - ENGINE TEMPERATURE GAUGE
3 - LEFT TURN INDICATOR 15 - SECURITY INDICATOR
4 - TACHOMETER 16 - GEAR SELECTOR INDICATOR DISPLAY (INCLUDES
CRUISE & UPSHIFT INDICATORS)
5 - AIRBAG INDICATOR 17 - CHECK GAUGES INDICATOR
6 - HIGH BEAM INDICATOR 18 - BRAKE INDICATOR
7 - SEATBELT INDICATOR 19 - ABS INDICATOR
8 - SPEEDOMETER 20 - ODOMETER/TRIP ODOMETER DISPLAY (INCLUDES
ENGINE HOURS, WASHER FLUID, LAMP OUTAGE, TOW/HAUL
& SERVICE 4x4 INDICATORS)
9 - RIGHT TURN INDICATOR 21 - ODOMETER/TRIP ODOMETER SWITCH BUTTON
10 - OIL PRESSURE GAUGE 22 - FUEL GAUGE
11 - CARGO LAMP INDICATOR 23 - LOW FUEL INDICATOR
12 - DOOR AJAR INDICATOR 24 - TRANSMISSION OVERTEMP INDICATOR
8J - 6 INSTRUMENT CLUSTERDR
INSTRUMENT CLUSTER (Continued)

- ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/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 high coolant tem-
perature, the algorithm can drive the gauge pointer
to an extreme position and the microprocessor can
sound a chime through the on-board audible tone
generator to provide distinct visual and audible indi-
cations of a problem to the vehicle operator. The
instrument cluster circuitry may also produce audi-
ble warnings for other electronic modules in the vehi-
cle based upon electronic tone request messages
received over the PCI data bus. Each audible warn-ing is intended to provide the vehicle operator with
an audible alert to supplement a visual indication.
The EMIC circuitry operates on battery current
received through a fused B(+) fuse in the Integrated
Power Module (IPM) on a non-switched fused B(+)
circuit, and on battery current received through a
fused ignition switch output (run-start) fuse in the
IPM on a fused ignition switch output (run-start) cir-
cuit. This arrangement allows the EMIC to provide
some features regardless of the ignition switch posi-
tion, while other features will operate only with the
ignition switch in the On or Start positions. The
EMIC circuitry is grounded through a ground circuit
and take out of the instrument panel wire harness
with an eyelet terminal connector that is secured by
a ground screw to a ground location near the center
of the instrument panel structural support.
The EMIC also has a self-diagnostic actuator test
capability, which will test each of the PCI bus mes-
Fig. 4 Gauges & Indicators - Diesel Engine
1 - MALFUNCTION INDICATOR LAMP 14 - ENGINE TEMPERATURE GAUGE
2 - VOLTAGE GAUGE 15 - SECURITY INDICATOR
3 - LEFT TURN INDICATOR 16 - GEAR SELECTOR INDICATOR DISPLAY (INCLUDES
CRUISE & UPSHIFT INDICATORS)
4 - TACHOMETER 17 - WATER-IN-FUEL INDICATOR
5 - AIRBAG INDICATOR 18 - BRAKE INDICATOR
6 - HIGH BEAM INDICATOR 19 - WAIT-TO-START INDICATOR
7 - SEATBELT INDICATOR 20 - ODOMETER/TRIP ODOMETER DISPLAY (INCLUDES
ENGINE HOURS, WASHER FLUID, LAMP OUTAGE, TOW/HAUL
& SERVICE 4x4 INDICATORS)
8 - SPEEDOMETER 21 - ODOMETER/TRIP ODOMETER SWITCH BUTTON
9 - RIGHT TURN INDICATOR 22 - FUEL GAUGE
10 - OIL PRESSURE GAUGE 23 - LOW FUEL INDICATOR
11 - CARGO LAMP INDICATOR 24 - TRANSMISSION OVERTEMP INDICATOR
12 - DOOR AJAR INDICATOR 25 - CHECK GAUGES INDICATOR
13 - ABS INDICATOR
DRINSTRUMENT CLUSTER 8J - 7
INSTRUMENT CLUSTER (Continued)