2003 DODGE RAM washer fluid

(6) Remove the power steering cooler mounting
bolts and position the power steering cooler out of
the way.
(7) Disconnect the transmission cooler lines at the
transmission. The transmission cooler will remain on
the radiator and can be removed as an assembly.
(8) Remove the lower shroud assembly and the
electronic viscous fan wiring from the upper shroud
assembly.
(9) Remove the two radiator upper mounting bolts
(Fig. 36).
(10) Lift radiator straight up and out of engine
compartment. The bottom of the radiator is equipped
with two alignment dowels that fit into holes in the
lower radiator support panel. Rubber biscuits (insu-
lators) are installed to these dowels. Take care not to
damage cooling fins or tubes on the radiator and air
conditioning condenser when removing.
CLEANING
Clean radiator fins are necessary for good heat
transfer. The radiator and oil cooler fins should be
cleaned when an accumulation of debris has
occurred. With the engine cold, apply cold water and
compressed air to the back (engine side) of the radi-
ator to flush the radiator and/or oil coolers of debris.
INSPECTION
Inspect the radiator side tanks for cracks, broken
or missing fittings also inspect the joint where the
tanks seam up to the radiator core for signs of leak-
age and/or deteriorating seals.
Inspect radiator core for corroded, bent or missing
cooling fins. Inspect the core for bent or damaged
cooling tubes.
INSTALLATION
(1) Install rubber insulators to alignment dowels
at lower part of radiator.
(2) Lower the radiator into position while guiding
the two alignment dowels into lower radiator sup-
port. Different alignment holes are provided in the
lower radiator support for each engine application.
(3) Install two upper radiator mounting bolts.
Tighten bolts to 11 N´m (95 in. lbs.) torque.
(4) Connect both radiator hoses and install hose
clamps.
(5) Connect transmission cooler lines to radiator
tank. Inspect quick connect fittings for debris and
install until an audible ªclickº is heard. Pull apart to
verify connection.
(6) Position power steering cooler on the radiator
and tighten nuts to 8.5M´N (75 in. lbs.)
(7) Attach electronic viscous fan wiring to upper
shroud ands install lower shroud.
(8) Position coolant recover tank hose, washer bot-
tle hose and the positive battery cable into the clips
located on the top of the radiator.
(9) Install air box and turbocharger inlet hose.
Tighten clamps to 4 N´M (35 in. lbs.).
(10) Position heater controls tofull heatposition.
(11) Fill cooling system with coolant (Refer to 7 -
COOLING - STANDARD PROCEDURE).
(12) Operate engine until it reaches normal tem-
perature. Check cooling system and automatic trans-
mission (if equipped) fluid levels.
RADIATOR PRESSURE CAP
DESCRIPTION
All cooling systems are equipped with a pressure
cap (Fig. 37). For 5.9L engines, the pressure cap is
located on top of the radiator outlet tank. For the
3.7L/4.7L engines, the pressure cap is located on top
of the coolant degas container. The cap releases pres-
sure at some point within a range of 97-to-124 kPa
(14-to-18 psi). The pressure relief point (in pounds) is
engraved on top of the cap
The cooling system will operate at pressures
slightly above atmospheric pressure. This results in a
higher coolant boiling point allowing increased radi-
ator cooling capacity. The cap contains a spring-
Fig. 36 Fan Shroud MountingÐ5.9L Diesel Engine
1 - RADIATOR SUPPORT
2 - UPPER FAN SHROUD
3 - BOLTS (2)
4 - LOWER FAN SHROUD
5 - RADIATOR
7 - 60 ENGINEDR
RADIATOR - 5.9L DIESEL (Continued)

LOW WASH INDICATOR
The Front Control Module (FCM) monitors the
washer reservoir. When the fluid is low the FCM
transmits a J1850 message over the bus. The instru-
ment cluster will chime and illuminate the LOW
WASH indicator. The indicator will remain on until
the fluid level is corrected.
AIR BAG
The Instrument Cluster monitors air bag system
via the J1850 bus communications from the air bag
module. The air bag module will transmit a message
once per second, over the J1850 bus, as to whether
the warning indicator should be on or off. The warn-
ing indicator indicates a part of the air bag system is
inoperative and needs to be serviced. Itdoes not
indicate that the air bag system will not deploy. If
the instrument cluster does not receive a message
from the air bag module for 3 consecutive seconds,
the Instrument will illuminate the warning indicator.The air bag module transmits a J1850 message
requesting the instrument cluster to perform a bulb
check each time the ignition is turned to the on posi-
tion
DIAGNOSIS AND TESTING - CHIME
CONDITIONS
NOTE: The Chime/Buzzer Warning System is Diag-
nosed using a DRBIIITScan Tool. Refer to the
proper Body Diagnostic Procedures Manual.
Visually inspect the related wiring harness connec-
tors. Look for broken, bent, pushed out, or corroded
terminals. If any of the conditions are present, repair
as necessary. If not use the DRBIIItscan tool and
the proper Body Diagnostic Procedure manual. For
complete circuit diagrams, refer toInstrument
Clusterin Wiring Systems.
8B - 2 CHIME/BUZZERDR
CHIME/BUZZER (Continued)

To avoid possible voltage spike damage to either
the Engine Control Module ECM, ignition key must
be off, and negative battery cables must be discon-
nected before unplugging ECM connectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove the 50±way and 60±way connector
bolts at the ECM. Note: Tthe connector bolt is a
female allen head. As bolt is being removed, very car-
fully remove connectors from the ECM.
(4) Remove five ECM mounting bolts and remove
ECM form the vehicle (Fig. 3).
INSTALLATION
Do not apply paint to ECM. Poor ground will
result.
(1) Position ECM to ECM support bracket and
install five mounting bolts. Tighten bolts to 24 N´m
(18 ft. lbs.).
(2) Check pin connectors in ECM and the 50±way
and 60±way connectors for corrosion or damage.
Repair as necessary.
(3) Clean pins in the 50±way and 60±way electri-
cal connectors with a quick-dry electrical contact
cleaner.
(4) Very carefully install the 50±way and 60±way
connectors to ECM. Tighten connector allen bolts.
(5) Install both negative battery cables.(6)Turn key to ON position. Without starting
engine, slowly press throttle pedal to floor and
then slowly release. This step must be done
(one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If
not done, possible DTC's may be set.
(7) Use DRB scan tool to erase any stored compan-
ion DTC's from ECM.
FRONT CONTROL MODULE
DESCRIPTION
The Front Control Module (FCM) is a micro con-
troller based module located in the left front corner
of the engine compartment. On this model the inte-
grated power module must be positioned aside in
order to access the front control module. The front
control module mates to the power distribution cen-
ter to form the Integrated Power Module (IPM). The
integrated power module connects directly to the bat-
tery and provides the primary means of circuit pro-
tection and power distribution for all vehicle
electrical systems. The front control module controls
power to some of these vehicle systems electrical and
electromechanical loads based on inputs received
from hard wired switch inputs and data received on
the PCI bus circuit (J1850).
For information on theIntegrated Power Mod-
ule Refer to the Power Distribution Sectionof
the service manual.
OPERATION
As messages are sent over the PCI bus circuit, the
front control module reads these messages and con-
trols power to some of the vehicles electrical systems
by completing the circuit to ground (low side driver)
or completing the circuit to 12 volt power (high side
driver). The following functions areControlledby
the Front Control Module:
²Headlamp Power with Voltage Regulation
²Windshield Wiper ªON/OFFº Relay Actuation
²Windshield Wiper ªHI/LOº Relay Actuation
²Windshield Washer Pump Motor
²Fog Lamp Relay Actuation
²Park Lamp Relay Actuation
²Horn Relay Actuation
The following inputs areReceived/Monitoredby
the Front Control Module:
²B+ Connection Detection
²Power Ground
²Ambient Temperature Sensing
²Ignition Switch Run
²Washer Fluid Level Switch
²Windshield Wiper Park Switch
²PCI Bus Circuit
Fig. 3 DIESEL ECM
1 - ENGINE CONTROL MODULE (ECM)
2 - ECM MOUNTING BOLT
3 - 50-WAY CONNECTOR
4 - SUPPORT PLATE
5 - 60-WAY CONNECTOR
DRELECTRONIC CONTROL MODULES 8E - 5
ENGINE CONTROL MODULE (Continued)

WASHER FLUID INDICATOR
DESCRIPTION.........................42
OPERATION...........................42WATER-IN-FUEL INDICATOR
DESCRIPTION.........................43
OPERATION...........................43
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 indicators
of the EMIC. A black plastic odometer/trip odometerswitch 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.
Sandwiched between the rear cover and the lens,
hood and mask unit is the cluster housing. The
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

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 appro-
priate 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 Indicator
²Electronic 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)
²Overdrive-Off Indicator (with Automatic
Transmission only)
²Seatbelt Indicator
²Security Indicator (with Sentry Key Immo-
bilizer & Vehicle Theft Security Systems only)
²Service Four-Wheel Drive Indicator (with
Four-Wheel Drive 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
board hardware, the cluster overlay, or the EMIC
housing are damaged or faulty, the entire EMIC mod-
DRINSTRUMENT CLUSTER 8J - 5
INSTRUMENT CLUSTER (Continued)

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 of
the 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
- ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/COMMUNICATION - OPERATION).
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,
OVERDRIVE-OFF & 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)

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-
sage-controlled functions of the cluster by lighting
the appropriate indicators, positioning the gauge nee-
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,
OVERDRIVE-OFF & 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)

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. The wait-to-start indicator is
located near the lower edge of the instrument cluster,
between the tachometer and the speedometer. 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 instru-
ment cluster overlay. The dark outer layer of the
overlay prevents the indicator from being clearly vis-
ible 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. The VFD is sol-
dered onto the cluster electronic circuit board and is
visible through a window with a smoked clear lens
located on the lower edge of the tachometer 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 light-
ing level as the odometer/trip odometer information
when it is illuminated by the instrument cluster elec-
tronic circuit board. The washer fluid indicator is ser-
viced 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
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-
8J - 42 INSTRUMENT CLUSTERDR