Fluid DODGE RAM 1500 1998 2.G Owners Manual

SHIFT SCHEDULES
As mentioned earlier, the TCM has programming
that allows it to select a variety of shift schedules.
Shift schedule selection is dependent on the follow-
ing:
²Shift lever position
²Throttle position²Engine load
²Fluid temperature
²Software level
As driving conditions change, the TCM appropri-
ately adjusts the shift schedule. Refer to the follow-
ing chart to determine the appropriate operation
expected, depending on driving conditions.
Schedule Condition Expected Operation
Extreme ColdOil temperature below -16É F -Park, Reverse, Neutral and 1st and
3rd gear only in D position, 2nd
gear only in Manual 2 or L
-No EMCC
Super ColdOil temperature between -12É F and
10É F- Delayed 2-3 upshift
- Delayed 3-4 upshift
- Early 4-3 coastdown shift
- High speed 4-2, 3-2, 2-1 kickdown
shifts are prevented
-Shifts at high throttle openings willl
be early.
- No EMCC
ColdOil temperature between 10É F and
36É F-Shift schedule is the same as
Super Cold except that the 2-3
upshifts are not delayed.
WarmOil temperature between 40É F and
80É F- Normal operation (upshift,
kickdowns, and coastdowns)
- No EMCC
HotOil temperature between 80É F and
240É F- Normal operation (upshift,
kickdowns, and coastdowns)
- Normal EMCC operation
OverheatOil temperature above 240É F or
engine coolant temperature above
244É F- Delayed 2-3 upshift
- Delayed 3-4 upshift
- 3rd gear FEMCC from 30-48 mph
- 3rd gear PEMCC above 35 mph
- Above 25 mph the torque
converter will not unlock unless the
throttle is closed or if a wide open
throttle 2nd PEMCC to 1 kickdown
is made
8E - 22 ELECTRONIC CONTROL MODULESDR
TRANSMISSION CONTROL MODULE (Continued)

WASHER FLUID INDICATOR
DESCRIPTION.........................44
OPERATION...........................44WATER-IN-FUEL INDICATOR
DESCRIPTION.........................45
OPERATION...........................45
INSTRUMENT CLUSTER
DESCRIPTION
The instrument cluster for this model is an Elec-
troMechanical Instrument Cluster (EMIC) that is
located in the instrument panel above the steering
column opening, directly in front of the driver (Fig.
1). The remainder of the EMIC, including the mounts
and the electrical connections, are concealed within
the instrument panel behind the cluster bezel.
Besides analog gauges and indicators, the EMIC
module incorporates two blue-green digital Vacuum
Fluorescent Display (VFD) units for displaying odom-
eter/trip odometer information, engine hours, auto-
matic transmission gear selector position (PRNDL),
several warning or reminder indications and certain
diagnostic information. The instrument cluster for
this model also includes the hardware and software
necessary to serve as the electronic body control mod-
ule and is sometimes referred to as the Cab Com-
partment Node or CCN.
The EMIC gauges and indicators are visible
through a dedicated opening in the cluster bezel on
the instrument panel and are protected by a clear
plastic cluster lens (Fig. 2) that is integral to a clus-
ter lens, hood and mask unit. Just behind the cluster
lens is the cluster hood and an integral cluster mask,
which are constructed of molded black plastic. The
cluster hood serves as a visor and shields the face of
the cluster from ambient light and reflections to
reduce glare, while the cluster mask serves to sepa-
rate and define the individual gauges and indicatorsof the EMIC. A black plastic odometer/trip odometer
switch button protrudes through dedicated holes in
the cluster mask and the cluster lens, located near
the lower edge of the cluster just to the left of the
tachometer. The molded plastic EMIC lens, hood and
mask unit has four integral mounting tabs, one each
on the upper and lower outboard corners of the unit.
These mounting tabs are used to secure the EMIC to
the molded plastic instrument panel cluster carrier
with four screws.
The rear of the cluster housing and the EMIC elec-
tronic circuitry are protected by a molded plastic rear
cover, which is secured to the cluster housing with a
single screw, while eight screws installed around the
outside perimeter of the rear cover secure it to the
cluster lens, hood and mask unit. The rear cover
includes clearance holes for service access to each of
the eleven incandescent bulb and bulb holder units
installed on the cluster circuit board for general illu-
mination lighting and for the cluster connector recep-
tacles. The connector receptacles on the back of the
cluster electronic circuit board connect the EMIC to
the vehicle electrical system through three take outs
with connectors from the instrument panel wire har-
ness. The EMIC also has an integral interface con-
nector on the back of the cluster circuit board that
joins it to the optional external RKE receiver through
a connector receptacle that is integral to that unit.
The rear cover includes a molded receptacle and two
latch features to secure the RKE receiver on vehicles
that are so equipped.
Fig. 1 Instrument Cluster
1 - INSTRUMENT PANEL
2 - INSTRUMENT CLUSTER
Fig. 2 Instrument Cluster Components
1 - SCREW (9)
2 - REAR COVER
3 - CLUSTER HOUSING
4 - LENS, HOOD & MASK
8J - 2 INSTRUMENT CLUSTERDR

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)

BRAKE/PARK BRAKE
INDICATOR
DESCRIPTION
A brake indicator is standard equipment on all
instrument clusters (Fig. 10). The brake indicator is
located near the lower edge of the instrument cluster,
between the tachometer and the speedometer. The
brake indicator consists of stencil-like cutouts of the
word ªBRAKEº and the International Control and
Display Symbol icon for ªBrake Failureº 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 Light Emitting Diode (LED) behind the cutout
in the opaque layer of the overlay causes the
ªBRAKEº text and the icon to appear in red through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by the LED,
which is soldered onto the instrument cluster elec-
tronic circuit board. The brake indicator is serviced
as a unit with the instrument cluster.
OPERATION
The brake indicator gives an indication to the vehi-
cle operator when the parking brake is applied, when
there are certain brake hydraulic system malfunc-
tions as indicated by a low brake hydraulic fluid level
condition, or when the brake fluid level switch is dis-
connected. The brake indicator can also give an indi-
cation when certain faults are detected in the
Antilock Brake System (ABS). This indicator is con-
trolled by a transistor on the instrument cluster cir-
cuit board based upon cluster programming,
electronic messages received by the cluster from the
Controller Antilock Brake (CAB) over the Program-
mable Communications Interface (PCI) data bus, and
a hard wired input from the park brake switch. The
brake indicator Light Emitting Diode (LED) is com-
pletely controlled by the instrument cluster logic cir-
cuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the brake indicator for the following reasons:²Bulb Test- Each time the ignition switch is
turned to the On position the brake indicator is illu-
minated by the instrument cluster for about two sec-
onds as a bulb test.
²Brake Lamp-On Message- Each time the
cluster receives a lamp-on message from the CAB,
the brake indicator will be illuminated. The CAB can
also send brake lamp-on messages as feedback dur-
ing ABS diagnostic procedures. 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.
²Park Brake Switch Input- Each time the
cluster detects ground on the park brake switch
sense circuit (park brake switch closed = park brake
applied or not fully released) while the ignition
switch is in the On position, the brake indicator
flashes on and off. The indicator continues to flash
until the park brake switch sense input to the cluster
is an open circuit (park brake switch open = park
brake fully released), or until the ignition switch is
turned to the Off position, whichever occurs first.
²Actuator Test- Each time the instrument clus-
ter is put through the actuator test, the brake indi-
cator will be turned on, then off again during the
bulb check portion of the test to confirm the function-
ality of the LED and the cluster control circuitry.
The park brake switch on the park brake pedal
mechanism provides a hard wired ground input to
the instrument cluster circuitry through the park
brake switch sense circuit whenever the park brake
is applied or not fully released. The CAB continually
monitors the ABS system circuits and sensors,
including the brake fluid level switch on the brake
master cylinder reservoir, to decide whether the sys-
tem is in good operating condition. The CAB then
sends the proper lamp-on or lamp-off messages to the
instrument cluster. If the CAB sends a lamp-on mes-
sage after the bulb test, it indicates that the CAB
has detected a brake hydraulic 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.
For further diagnosis of the brake indicator or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). The park brake
switch input to the instrument cluster can be diag-
nosed using conventional diagnostic tools and meth-
ods. For proper diagnosis of the brake fluid level
switch, the ABS, the CAB, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the brake indicator, a DRBIIItscan tool
is required. Refer to the appropriate diagnostic infor-
mation.
Fig. 10 Brake Indicator
DRINSTRUMENT CLUSTER 8J - 19

required. Refer to the appropriate diagnostic infor-
mation.
TRANS TEMP INDICATOR
DESCRIPTION
A transmission over-temperature indicator is stan-
dard equipment on all instrument clusters (Fig. 31).
However, on vehicles not equipped with an optional
automatic transmission, this indicator is electroni-
cally disabled. The transmission over-temperature
indicator is located on the left side of the instrument
cluster, to the left of the fuel gauge. The transmission
over-temperature indicator consists of a stencil-like
cutout of the words ªTRANS TEMPº 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
Light Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the ªTRANS
TEMPº text to appear in red through the translucent
outer layer of the overlay when the indicator is illu-
minated from behind by the LED, which is soldered
onto the instrument cluster electronic circuit board.
The transmission over-temperature indicator is ser-
viced as a unit with the instrument cluster.
OPERATION
The transmission over-temperature indicator gives
an indication to the vehicle operator when the trans-
mission fluid temperature is excessive, which may
lead to accelerated transmission component wear or
failure. 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 Powertrain Control Module
(PCM) over the Programmable Communications
Interface (PCI) data bus. The transmission over-tem-
perature indicator Light Emitting Diode (LED) is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the transmission over-temperature indicator
for the following reasons:²Bulb Test- Each time the ignition switch is
turned to the On position the transmission over-tem-
perature indicator is illuminated for about two sec-
onds as a bulb test.
²Trans Over-Temp Lamp-On Message- Each
time the cluster receives a trans over-temp lamp-on
message from the PCM indicating that the transmis-
sion fluid temperature is 135É C (275É F) or higher,
the indicator will be illuminated and a single chime
tone is sounded. The indicator remains illuminated
until the cluster receives a trans over-temp lamp-off
message from the PCM, or until the ignition switch
is turned to the Off position, whichever occurs first.
The chime tone feature will only repeat during the
same ignition cycle if the transmission over-tempera-
ture indicator is cycled off and then on again by the
appropriate trans over-temp messages from the PCM.
²Actuator Test- Each time the cluster is put
through the actuator test, the transmission over-tem-
perature indicator will be turned on, then off again
during the bulb check portion of the test to confirm
the functionality of the LED and the cluster control
circuitry.
The PCM continually monitors the transmission
temperature sensor to determine the transmission
operating condition. The PCM then sends the proper
trans over-temp lamp-on or lamp-off messages to the
instrument cluster. If the instrument cluster turns on
the transmission over-temperature indicator due to a
high transmission oil temperature condition, it may
indicate that the transmission and/or the transmis-
sion cooling system are being overloaded or that they
require service. For further diagnosis of the trans-
mission over-temperature indicator or the instrument
cluster circuitry that controls the LED, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
transmission temperature sensor, the PCM, the PCI
data bus, or the electronic message inputs to the
instrument cluster that control the transmission
over-temperature indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
TURN SIGNAL INDICATOR
DESCRIPTION
Two turn signal indicators, one right and one left,
are standard equipment on all instrument clusters
(Fig. 32). The turn signal indicators are located near
Fig. 31 Transmission Overtemp Indicator
Fig. 32 Turn Signal Indicators
8J - 40 INSTRUMENT CLUSTERDR
TOW/HAUL INDICATOR (Continued)

WAIT-TO-START INDICATOR
DESCRIPTION
A wait-to-start indicator is only found in the
instrument clusters for vehicles equipped with an
optional diesel engine (Fig. 35). The wait-to-start
indicator is located near the lower edge of the instru-
ment cluster, between the tachometer and the speed-
ometer. The wait-to-start indicator consists of stencil-
like cutout of the International Control and Display
Symbol icon for ªDiesel Preheatº 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
Light Emitting Diode (LED) 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 the indicator is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The wait-
to-start indicator is serviced as a unit with the
instrument cluster.
OPERATION
The wait-to-start indicator gives an indication to
the vehicle operator when the air temperature within
the diesel engine intake manifold is too cool for effi-
cient and reliable engine starting, and that the
intake air heater grids are energized in their pre-
heat operating mode. This 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 Engine Control
Module (ECM) over the Programmable Communica-
tions Interface (PCI) data bus. The wait-to-start indi-
cator Light Emitting Diode (LED) is completely
controlled by the instrument cluster logic circuit, and
that logic will only allow this indicator to operate
when the instrument cluster receives a battery cur-
rent input on the fused ignition switch output (run-
start) circuit. Therefore, the LED will always be off
when the ignition switch is in any position except On
or Start. The LED only illuminates when it is pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
wait-to-start indicator for the following reasons:
²Wait-To-Start Lamp-On Message- Each time
the cluster receives a wait-to-start lamp-on message
from the ECM indicating that the air temperature
within the intake manifold is too cool for efficient
and reliable engine starting, the wait-to-start indica-
tor will be illuminated. The indicator remains illumi-nated until the cluster receives a wait-to-start lamp-
off message, until the ECM detects that the engine is
running or until the ignition switch is turned to the
Off position, whichever occurs first.
²Actuator Test- Each time the cluster is put
through the actuator test, the wait-to-start indicator
will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The ECM continually monitors the engine intake
air temperature sensor to determine when the intake
air heater grids should be energized in their pre-heat
operating mode. The ECM then sends the proper
wait-to-start lamp-on and lamp-off messages to the
instrument cluster. For further diagnosis of the wait-
to-start indicator or the instrument cluster circuitry
that controls the indicator, (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the engine intake
air temperature sensor, the intake air heater grid
control circuits, the ECM, the PCI data bus, or the
electronic message inputs to the instrument cluster
that control the wait-to-start indicator, a DRBIIIt
scan tool is required. Refer to the appropriate diag-
nostic information.
WASHER FLUID INDICATOR
DESCRIPTION
A washer fluid indicator is standard equipment on
all instrument clusters. The washer fluid indicator
consists of the words ªLOW WASHº, which appear in
the lower portion of the odometer/trip odometer Vac-
uum-Fluorescent Display (VFD) unit (Fig. 36). The
VFD is soldered onto the cluster electronic circuit
board and is visible through a window with a smoked
clear lens located on the lower edge of the tachome-
ter gauge dial face of the cluster overlay. The dark
lens over the VFD prevents the indicator from being
clearly visible when it is not illuminated. The ªLOW
WASHº text appears in an amber color and at the
same lighting level as the odometer/trip odometer
information when it is illuminated by the instrument
cluster electronic circuit board. The washer fluid
indicator is serviced as a unit with the VFD in the
instrument cluster.
OPERATION
The washer fluid indicator gives an indication to
the vehicle operator that the fluid level in the washer
Fig. 35 Wait-To-Start Indicator
Fig. 36 Washer Fluid Indicator
8J - 44 INSTRUMENT CLUSTERDR

reservoir is low. This indicator is controlled by the
instrument cluster circuit board based upon cluster
programming and electronic messages received by
the cluster from the Front Control Module (FCM)
over the Programmable Communications Interface
(PCI) data bus. The washer fluid indicator is com-
pletely controlled by the instrument cluster logic cir-
cuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the indicator will
always be off when the ignition switch is in any posi-
tion except On or Start. The indicator only illumi-
nates when it is switched to ground by the
instrument cluster circuitry. The instrument cluster
will turn on the washer fluid indicator for the follow-
ing reasons:
²Washer Fluid Indicator Lamp-On Message-
Each time the cluster receives a washer fluid indica-
tor lamp-on message from the FCM indicating that a
low washer condition has been detected for sixty con-
secutive seconds, the washer fluid indicator is illumi-
nated and a single chime tone is sounded. The
indicator remains illuminated until the cluster
receives a washer fluid indicator lamp-off message
for sixty consecutive seconds from the FCM or until
the ignition switch is turned to the Off position,
whichever occurs first. The chime tone feature will
only repeat during the same ignition cycle if the
washer fluid indicator is cycled off and then on again
by the appropriate washer fluid lamp messages from
the FCM.
²Actuator Test- Each time the cluster is put
through the actuator test, the washer fluid indicator
will be turned on, then off again during the VFD por-
tion of the test to confirm the functionality of the
VFD and the cluster control circuitry.
The FCM continually monitors the washer fluid
level switch in the washer reservoir to determine the
level of the washer fluid. The FCM then sends the
proper washer fluid indicator lamp-on and lamp-off
messages to the instrument cluster. For further diag-
nosis of the washer fluid indicator or the instrument
cluster circuitry that controls the indicator, (Refer to
8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAG-
NOSIS AND TESTING). For proper diagnosis of the
washer fluid level switch, the FCM, the PCI data
bus, or the electronic message inputs to the instru-
ment cluster that control the washer fluid indicator,
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.WATER-IN-FUEL INDICATOR
DESCRIPTION
A water-in-fuel indicator is only found in the
instrument clusters for vehicles equipped with an
optional diesel engine (Fig. 37). The water-in-fuel
indicator is located near the lower edge of the instru-
ment cluster, between the tachometer and the speed-
ometer. The water-in-fuel indicator consists of stencil-
like cutout of the International Control and Display
Symbol icon for ªWater In Fuelº 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 Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appear
in red through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The
water-in-fuel indicator is serviced as a unit with the
instrument cluster.
OPERATION
The water-in-fuel indicator gives an indication to
the vehicle operator when there is excessive water in
the fuel system. This indicator is controlled by a
transistor on the instrument cluster circuit board
based upon the cluster programming and electronic
messages received by the cluster from the Engine
Control Module (ECM) over the Programmable Com-
munications Interface (PCI) data bus. The water-in-
fuel indicator Light Emitting Diode (LED) is
completely controlled by the instrument cluster logic
circuit, and that logic will only allow this indicator to
operate when the instrument cluster receives a bat-
tery current input on the fused ignition switch out-
put (run-start) circuit. Therefore, the LED will
always be off when the ignition switch is in any posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the water-in-fuel indicator for the following
reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the water-in-fuel indicator
is illuminated for about two seconds as a bulb test.
²Water-In-Fuel Lamp-On Message- Each time
the cluster receives a water-in-fuel lamp-on message
from the ECM indicating that there is excessive
Fig. 37 Water-In-Fuel Indicator
DRINSTRUMENT CLUSTER 8J - 45
WASHER FLUID INDICATOR (Continued)

WIPERS/WASHERS
TABLE OF CONTENTS
page page
WIPERS/WASHERS
DESCRIPTION..........................1
OPERATION............................4
DIAGNOSIS AND TESTING - WIPER &
WASHER SYSTEM.....................6
CLEANING - WIPER & WASHER SYSTEM.....6
INSPECTION - WIPER & WASHER SYSTEM . . . 7
CHECK VALVE
DESCRIPTION..........................7
OPERATION............................8
REMOVAL.............................8
INSTALLATION..........................8
WASHER FLUID LEVEL SWITCH
DESCRIPTION..........................9
OPERATION............................9
REMOVAL.............................10
INSTALLATION.........................11
WASHER HOSES/TUBES
DESCRIPTION.........................11
OPERATION...........................11
WASHER NOZZLE
DESCRIPTION.........................11
OPERATION...........................12
REMOVAL.............................12
INSTALLATION.........................12
WASHER PUMP/MOTOR
DESCRIPTION.........................13
OPERATION...........................13
REMOVAL.............................14
INSTALLATION.........................14
WASHER RESERVOIR
DESCRIPTION.........................14
OPERATION...........................15
REMOVAL
REMOVAL - EXCEPT DIESEL ENGINE.....15REMOVAL - DIESEL ENGINE............16
INSTALLATION
INSTALLATION - EXCEPT DIESEL ENGINE . . 17
INSTALLATION - DIESEL ENGINE.........17
WIPER ARM
DESCRIPTION.........................17
OPERATION...........................18
REMOVAL.............................18
INSTALLATION.........................18
WIPER BLADE
DESCRIPTION.........................18
OPERATION...........................19
REMOVAL.............................19
INSTALLATION.........................20
WIPER HIGH/LOW RELAY
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - WIPER HIGH/
LOW RELAY.........................21
REMOVAL.............................21
INSTALLATION.........................22
WIPER MODULE
DESCRIPTION.........................22
OPERATION...........................23
REMOVAL.............................23
INSTALLATION.........................23
WIPER ON/OFF RELAY
DESCRIPTION.........................24
OPERATION...........................25
DIAGNOSIS AND TESTING - WIPER ON/OFF
RELAY..............................25
REMOVAL.............................26
INSTALLATION.........................26
WIPERS/WASHERS
DESCRIPTION
An electrically operated intermittent wiper and
washer system is standard factory-installed safety
equipment on this model (Fig. 1). The wiper and
washer system includes the following major compo-
nents, which are described in further detail else-
where in this service information:
²Check Valve- The washer system check valve
is integral to the wye fitting located in the washer
plumbing between the cowl plenum washer hose andthe washer nozzles, and is concealed beneath the
cowl plenum cover/grille panel at the base of the
windshield.
²Front Control Module- The Front Control
Module (FCM) is integral to the Integrated Power
Module (IPM). The IPM is located in the engine com-
partment, near the battery. (Refer to 8 - ELECTRI-
CAL/POWER DISTRIBUTION/INTEGRATED
POWER MODULE - DESCRIPTION).
²Instrument Cluster- In this model, the instru-
ment cluster is also sometimes referred to as the Cab
Control Node (CCN). The instrument cluster is
located in the instrument panel above the steering
DRWIPERS/WASHERS 8R - 1