2002 DODGE RAM display

engine coolant temperature gauge is serviced as a
unit with the instrument cluster.
OPERATION
The engine coolant temperature gauge gives an
indication to the vehicle operator of the engine cool-
ant temperature. This gauge is controlled by the
instrument cluster circuit board based upon the clus-
ter programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) over the Chrysler Collision Detection (CCD)
data bus. The engine coolant temperature gauge is
an air core magnetic unit that receives battery cur-
rent on the instrument cluster electronic circuit
board through the fused ignition switch output (st-
run) circuit whenever the ignition switch is in the On
or Start positions. The cluster is programmed to
move the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Engine Temperature Message- Each time
the cluster receives a message from the PCM indicat-
ing the engine coolant temperature is between the
low end of normal [about 57É C (130É F) for gasoline
engines, or 60É C (140É F) for diesel engines] and the
high end of normal [about 129É C (264É F) for gaso-
line engines, or 116É C (240É F) for diesel engines],
the gauge needle is moved to the actual temperature
position on the gauge scale.
²Engine Temperature Low Message- Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is below
the low end of normal [about 57É C (130É F) for gas-
oline engines, or 60É C (140É F) for diesel engines],
the gauge needle is held at the lowest increment [57É
C (130É F) for gasoline engines, or 60É C (140É F) for
diesel engines] at the far left end of the gauge scale.
The gauge needle remains at the far left end of the
scale until the cluster receives a message from the
PCM indicating that the engine temperature is above
about 57É C (130É F) for gasoline engines, or 60É C
(140É F) for diesel engines, or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Engine Temperature High Message- Each
time the cluster receives a message from the PCM
indicating the engine coolant temperature is above
about 122É C (253É F) for gasoline engines, or 112É C
(233É F) for diesel engines, the gauge needle is moved
to the appropriate position on the gauge scale, the
check gauges indicator is illuminated, and a single
chime tone is sounded. The check gauges indicator
remains illuminated until the cluster receives a mes-
sage from the PCM indicating that the engine tem-perature is below about 119É C (246É F) for gasoline
engines, or 109É C (226É F) for diesel engines, 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
check gauges indicator is cycled off and then on
again by the appropriate engine temperature mes-
sages from the PCM.
²Message Failure- If the cluster fails to receive
an engine temperature message, it will hold the
gauge needle at the last indication until a new mes-
sage is received, 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 gauge needle will be
swept to several calibration points on the gauge scale
in a prescribed sequence in order to confirm the func-
tionality of the gauge and the cluster control cir-
cuitry.
The PCM continually monitors the engine coolant
temperature sensor to determine the engine operat-
ing temperature. The PCM then sends the proper
engine coolant temperature messages to the instru-
ment cluster. For further diagnosis of the engine cool-
ant temperature gauge or the instrument cluster
circuitry that controls the gauge, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster turns on
the check gauges indicator due to a high engine tem-
perature gauge reading, it may indicate that the
engine or the engine cooling system requires service.
For proper diagnosis of the engine coolant tempera-
ture sensor, the PCM, the CCD data bus, or the mes-
sage inputs to the instrument cluster that control the
engine coolant temperature gauge, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
FUEL GAUGE
DESCRIPTION
A fuel gauge is standard equipment on all instru-
ment clusters. The fuel gauge is located in the lower
right quadrant of the instrument cluster, below the
oil pressure gauge. The fuel gauge consists of a mov-
able gauge needle or pointer controlled by the instru-
ment cluster circuitry and a fixed 90 degree scale on
the cluster overlay that reads left-to-right from E (or
Empty) to F (or Full). An International Control and
Display Symbol icon for ªFuelº is located on the clus-
ter overlay, directly below the highest graduation of
the gauge scale. The text ªFUEL DOORº and an
arrowhead pointed to the left side of the vehicle is
imprinted on the cluster overlay directly below the
fuel gauge to provide the driver with a reminder as
BR/BEINSTRUMENT CLUSTER 8J - 19
ENGINE TEMPERATURE GAUGE (Continued)

instrument cluster housing with two screws. A face
plate on the indicator housing is visible through a
rectangular cutout in the lower right corner of the
instrument cluster overlay, just below the fuel gauge.
Vehicles with a manual transmission have a block-off
plate mounted to the back of the instrument cluster
behind this cutout in the overlay, in place of the gear
selector indicator. Near the top of this face plate the
following characters are imprinted from left to right:
ªP,º ªR,º ªN,º ªD,º ª2,º and ª1.º Respectively, these
characters represent the park, reverse, neutral,
drive, second gear, and first gear positions of the
transmission gear selector lever on the steering col-
umn. Directly below each character on the face plate
is a small, rectangular window, and behind these
windows is a single, movable red pointer.
The gear selector indicator graphics are white
against a black field except for the single red pointer,
making them clearly visible within the instrument
cluster in daylight. When illuminated from behind by
the panel lamps dimmer controlled cluster illumina-
tion lighting with the exterior lamps turned On, the
white graphics appear blue-green, while the red
pointer still appears red. Indicator illumination is
provided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The gear selector indicator is
available for service replacement separate from the
instrument cluster. The instrument cluster must be
removed from the instrument panel for service access
to the gear selector indicator. (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - REMOVAL).
OPERATION
The mechanical gear selector indicator gives an
indication of the transmission gear that has been
selected with the automatic transmission gear selec-
tor lever. A red pointer appears in a window below
the character in the indicator representing the trans-
mission gear that has been selected. The small,
spring-loaded pointer moves on a track through a
trolley-like mechanism within the indicator housing.
A short length of small diameter stranded cable is
attached to one side of the pointer trolley and is
encased in a tubular plastic housing that exits the
right side of the indicator. The cable is routed
through the instrument panel and under the steering
column to the left side of the column. The looped end
of the cable is hooked over the end of the PRNDL
driver lever on the steering column gearshift mecha-
nism, and the cable housing is secured in a molded
plastic adjuster and bracket on the column housing.
When the gear selector lever is moved the PRNDL
driver lever moves, which moves the pointer through
the mechanical actuator cable. The cable adjuster
and bracket unit mounted on the steering columnhousing provides a mechanical means of calibrating
the gear selector indicator mechanism. (Refer to 19 -
STEERING/COLUMN - INSTALLATION).
HIGH BEAM INDICATOR
DESCRIPTION
A high beam indicator is standard equipment on
all instrument clusters. The high beam indicator is
located near the upper edge of the instrument cluster
overlay, between the tachometer and the speedome-
ter. The high beam indicator consists of a stenciled
cutout of the International Control and Display Sym-
bol icon for ªHigh Beamº 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 blue lens behind
the cutout in the opaque layer of the overlay causes
the icon to appear in blue through the translucent
outer layer of the overlay when it is illuminated from
behind by a replaceable incandescent bulb and bulb
holder unit located on the instrument cluster elec-
tronic circuit board. The high beam indicator is ser-
viced as a unit with the instrument cluster.
OPERATION
The high beam indicator gives an indication to the
vehicle operator when the headlamp high beams are
illuminated. This indicator is hard wired on the
instrument cluster electronic circuit board, and is
controlled by a headlamp beam select switch input to
the cluster. The headlamp high beam indicator bulb
receives battery current on the instrument cluster
electronic circuit board through a fused B(+) circuit
at all times; therefore, the indicator remains opera-
tional regardless of the ignition switch position. The
headlamp beam select switch is integral to the multi-
function switch on the left side of the steering col-
umn, and is connected in series between ground and
the headlamp high beam indicator. The indicator
bulb only illuminates when it is provided with a path
to ground through the high beam indicator driver cir-
cuit by the headlamp beam select switch. (Refer to 8
- ELECTRICAL/LAMPS/LIGHTING - EXTERIOR/
MULTI-FUNCTION SWITCH - OPERATION). The
high beam indicator can be diagnosed using conven-
tional diagnostic tools and methods.
DIAGNOSIS AND TESTING - HIGH BEAM
INDICATOR
The diagnosis found here addresses an inoperative
headlamp high beam indicator condition. If the prob-
lem being diagnosed is related to inoperative head-
lamp high beams, be certain to repair the headlamp
system before attempting to diagnose or repair the
BR/BEINSTRUMENT CLUSTER 8J - 21
GEAR SELECTOR INDICATOR (Continued)

high beam indicator. If no headlamp system problems
are found, the following procedure will help locate a
short or open in the high beam indicator circuit.
Refer to the appropriate wiring information. The wir-
ing information includes wiring diagrams, proper
wire and connector repair procedures, details of wire
harness routing and retention, connector pin-out
information and location views for the various wire
harness connectors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
INDICATOR DOES NOT ILLUMINATE WITH HIGH BEAMS
SELECTED
(1) Check the fused B(+) fuse (Fuse 14 - 10
ampere) in the Junction Block (JB). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
(Fuse 14 - 10 ampere) in the JB. If OK, go to Step 3.
If not OK, repair the open fused B(+) circuit between
the JB and the Power Distribution Center (PDC) as
required.
(3) Be certain that the headlamp high beams are
selected with the headlamp beam select switch by
turning the headlamp switch to the On position, pull-
ing the multi-function switch stalk toward the steer-
ing wheel, then inspecting the headlamps at the
front of the vehicle. Once the headlamp high beams
are selected, turn the headlamp switch to the Off
position. Disconnect and isolate the battery negative
cable. Remove the instrument cluster from the
instrument panel. Reconnect the battery negative
cable. Check for battery voltage at the fused B(+) cir-
cuit cavity of the instrument panel wire harness con-
nector (Connector C1) for the instrument cluster. If
OK, go to Step 4. If not OK, repair the open fused
B(+) circuit between the instrument cluster and the
JB as required.
(4) Disconnect and isolate the battery negative
cable. Check for continuity between the high beam
indicator driver circuit cavity of the instrument panel
wire harness connector (Connector C2) for the instru-ment cluster and a good ground. There should be
continuity. If OK, replace the faulty headlamp high
beam indicator bulb and bulb holder unit. If not OK,
repair the open high beam indicator driver circuit
between the instrument cluster and the headlamp
beam select (multi-function) switch as required.
INDICATOR STAYS ILLUMINATED WITH HIGH BEAMS NOT
SELECTED
(1) Be certain that the headlamp low beams are
selected with the headlamp beam select switch by
turning the headlamp switch to the On position, pull-
ing the multi-function switch stalk toward the steer-
ing wheel, then inspecting the headlamps at the
front of the vehicle. Once the headlamp low beams
are selected, turn the headlamp switch to the Off
position. Disconnect and isolate the battery negative
cable. Remove the instrument cluster from the
instrument panel. Check for continuity between the
high beam indicator driver circuit cavity of the
instrument panel wire harness connector (Connector
C2) for the instrument cluster and a good ground.
There should be no continuity. If OK, replace the
faulty instrument cluster. If not OK, repair the
shorted high beam indicator driver circuit between
the instrument cluster and the headlamp beam select
(multi-function) switch as required.
LOW FUEL INDICATOR
DESCRIPTION
A low fuel indicator is standard equipment on all
instrument clusters. The low fuel indicator is located
near the lower edge of the instrument cluster overlay,
to the right of center. The low fuel indicator consists
of a stenciled cutout of the International Control and
Display Symbol icon for ªFuelº in the opaque layer of
the instrument cluster overlay. The dark outer layer
of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
overlay causes the icon to appear in amber through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by a Light Emit-
ting Diode (LED) soldered onto the instrument clus-
ter electronic circuit board. The low fuel indicator is
serviced as a unit with the instrument cluster.
OPERATION
The low fuel indicator gives an indication to the
vehicle operator when the level of fuel in the fuel
tank becomes low. 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 Powertrain
Control Module (PCM) over the Chrysler Collision
8J - 22 INSTRUMENT CLUSTERBR/BE
HIGH BEAM INDICATOR (Continued)

Detection (CCD) data bus. The low fuel indicator
Light Emitting Diode (LED) receives battery current
on the instrument cluster electronic circuit board
through the fused ignition switch output (st-run) cir-
cuit whenever the ignition switch is in the On or
Start positions; therefore, the LED will always be off
when the ignition switch is in any position except On
or Start. The LED only illuminates when it is pro-
vided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
low fuel indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the indicator is illuminated
for about two seconds as a bulb test.
²Less Than 12.5 Percent Tank Full Message-
Each time the cluster receives messages from the
PCM indicating the percent tank full is 12.5 (one-
eighth) or less for 10 consecutive seconds and the
vehicle speed is zero, or for 60 consecutive seconds
and the vehicle speed is greater than zero, the low
fuel indicator is illuminated and a single chime tone
is sounded. The low fuel indicator remains illumi-
nated until the cluster receives messages from the
PCM indicating that the percent tank full is greater
than 12.5 (one-eighth) for 10 consecutive seconds and
the vehicle speed is zero, or for 60 consecutive sec-
onds and the vehicle speed is greater than zero, 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 low
fuel indicator is cycled off and then on again by the
appropriate percent tank full messages from the
PCM.
²Less Than Empty Percent Tank Full Mes-
sage- Each time the cluster receives a message from
the PCM indicating the percent tank full is less than
empty, the low fuel indicator is illuminated immedi-
ately. This message would indicate that the fuel tank
sender input to the PCM is a short circuit.
²More Than Full Percent Tank Full Message
- Each time the cluster receives a message from the
PCM indicating the percent tank full is more than
full, the low fuel indicator is illuminated immedi-
ately. This message would indicate that the fuel tank
sender input to the PCM is an open circuit.
²Actuator Test- Each time the cluster is put
through the actuator test, the indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The PCM continually monitors the fuel tank send-
ing unit, then sends the proper messages to the
instrument cluster. For further diagnosis of the low
fuel indicator or the instrument cluster circuitry that
controls the LED, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-ING). For proper diagnosis of the fuel tank sending
unit, the PCM, the CCD data bus, or the message
inputs to the instrument cluster that control the low
fuel indicator, a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
MALFUNCTION INDICATOR
LAMP MIL
DESCRIPTION
A Malfunction Indicator Lamp (MIL) is standard
equipment on all instrument clusters. The MIL is
located near the lower edge of the instrument cluster
overlay, to the left of center. The MIL consists of a
stencilled cutout of the International Control and
Display Symbol icon for ªEngineº in the opaque layer
of the instrument cluster overlay. The dark outer
layer of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
overlay causes the icon to appear in amber through
the translucent outer layer of the overlay when the
indicator is illuminated from behind by a Light Emit-
ting Diode (LED) soldered onto the instrument clus-
ter electronic circuit board. The MIL is serviced as a
unit with the instrument cluster.
OPERATION
The Malfunction Indicator Lamp (MIL) gives an
indication to the vehicle operator when the Power-
train Control Module (PCM) has recorded a Diagnos-
tic Trouble Code (DTC) for an On-Board Diagnostics
II (OBDII) emissions-related circuit or component
malfunction. In addition, on models with a diesel
engine an Engine Control Module (ECM) supple-
ments the PCM, and can also record an OBDII DTC.
The MIL is controlled by a transistor on the instru-
ment cluster circuit board based upon cluster pro-
gramming and electronic messages received by the
cluster from the PCM or ECM over the Chrysler Col-
lision Detection (CCD) data bus. The MIL Light
Emitting Diode (LED) receives battery current on the
instrument cluster electronic circuit board through
the fused ignition switch output (st-run) circuit
whenever the ignition switch is in the On or Start
positions; therefore, the LED will always be off when
the ignition switch is in any position except On or
Start. The LED only illuminates when it is provided
a path to ground by the instrument cluster transis-
tor. The instrument cluster will turn on the MIL for
the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the indicator is illuminated
for about seven seconds as a bulb test.
BR/BEINSTRUMENT CLUSTER 8J - 23
LOW FUEL INDICATOR (Continued)

²PCM Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the PCM or
ECM, the indicator will be illuminated. The indicator
can be flashed on and off, or illuminated solid, as dic-
tated by the PCM or ECM message. For some DTC's,
if a problem does not recur, the PCM or ECM will
send a lamp-off message automatically. Other DTC's
may require that a fault be repaired and the PCM or
ECM be reset before a lamp-off message will be sent.
For more information on the PCM, the ECM, and the
DTC set and reset parameters, (Refer to 25 - EMIS-
SIONS CONTROL - OPERATION).
²Communication Error- If the cluster receives
no lamp-on message from the PCM or ECM for
twenty seconds, the MIL is illuminated by the instru-
ment cluster to indicate a loss of bus communication.
The indicator remains controlled and illuminated by
the cluster until a valid lamp-on message is received
from the PCM or ECM.
²Actuator Test- Each time the cluster is put
through the actuator test, the indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The PCM/ECM continually monitor the fuel and
emissions system circuits and sensors to decide
whether the system is in good operating condition.
The PCM or ECM then sends the proper lamp-on or
lamp-off messages to the instrument cluster. For fur-
ther diagnosis of the MIL or the instrument cluster
circuitry that controls the LED, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). If the instrument cluster turns on
the MIL after the bulb test, it may indicate that a
malfunction has occurred and that the fuel and emis-
sions systems may require service. For proper diag-
nosis of the fuel and emissions systems, the PCM,
the ECM, the CCD data bus, or the message inputs
to the instrument cluster that control the MIL, a
DRBIIItscan tool is required. Refer to the appropri-
ate diagnostic information.
ODOMETER
DESCRIPTION
An odometer and trip odometer are standard
equipment in all instrument clusters. The odometer
and trip odometer information are displayed in a
common electronic Vacuum-Fluorescent Display
(VFD), which is visible through a small window cut-
out located in the left lower quadrant of the cluster
overlay. However, the odometer and trip odometer
information are not displayed simultaneously. The
trip odometer reset switch on the instrument cluster
circuit board toggles the display between odometerand trip odometer modes by depressing the odometer/
trip odometer switch knob that extends through the
lower edge of the cluster lens, just right of the
tachometer. Both the odometer and the trip odometer
information is stored in the instrument cluster mem-
ory.
The odometer can display values up to 499,999
kilometers (499,999 miles). The odometer latches at
these values, and will not roll over to zero. The trip
odometer can display values up to 999.9 kilometers
(999.9 miles) before it rolls over to zero. The odome-
ter display does not have a decimal point and will
not show values less than a full unit (kilometer or
mile), the trip odometer display does have a decimal
point and will show tenths of a unit (kilometer or
mile). The unit of measure (kilometers or miles) for
the odometer and trip odometer display is not shown
in the VFD. The unit of measure for the instrument
cluster odometer/trip odometer is selected at the time
that it is manufactured, and cannot be changed. Dur-
ing daylight hours (exterior lamps Off) the VFD is
illuminated at full brightness for clear visibility. At
night (exterior lamps are On) the VFD lighting level
is adjusted with the other cluster illumination lamps
using the panel lamps dimmer thumbwheel on the
headlamp switch. However, a ªParadeº mode position
of the panel lamps dimmer thumbwheel allows the
VFD to be illuminated at full brightness while the
exterior lamps are turned On during daylight hours.
The VFD, the trip odometer switch, and the trip
odometer switch button are serviced as a unit with
the instrument cluster.
OPERATION
The odometer and trip odometer give an indication
to the vehicle operator of the distance the vehicle has
traveled. This gauge is controlled by the instrument
cluster circuit board based upon the cluster program-
ming and electronic messages received by the cluster
from the Powertrain Control Module (PCM) over the
Chrysler Collision Detection (CCD) data bus. The
odometer and trip odometer information is displayed
by the instrument cluster Vacuum Fluorescent Dis-
play (VFD), and the VFD will not display odometer
or trip odometer information after the ignition switch
is turned to the Off position. The instrument cluster
circuitry controls the VFD and provides the following
features:
²Odometer/Trip Odometer Display Toggling-
Actuating the trip odometer reset switch momen-
tarily with the ignition switch in the On position will
toggle the VFD between the odometer and trip odom-
eter display. Each time the ignition switch is turned
to the On position the VFD will automatically return
to the mode (odometer or trip odometer) last dis-
8J - 24 INSTRUMENT CLUSTERBR/BE
MALFUNCTION INDICATOR LAMP MIL (Continued)

played when the ignition switch was turned to the
Off position.
²Trip Odometer Reset- When the trip odome-
ter reset switch is pressed and held for longer than
about two seconds, the trip odometer will be reset to
000.0 kilometers (miles). The VFD must be display-
ing the trip odometer information in order for the
trip odometer information to be reset.
²Message Failure- If the cluster fails to receive
a distance message during normal operation, it will
flash the odometer/trip odometer distance informa-
tion on and off repeatedly until a distance message is
received, or until the ignition switch is turned to the
Off position, whichever occurs first. If the cluster
does not receive a distance message within one sec-
ond after the ignition switch is turned to the On posi-
tion, it will display the last distance message stored
in the cluster memory. If the cluster is unable to dis-
play distance information due to an error internal to
the cluster, the VFD display will be blank.
²Actuator Test- Each time the cluster is put
through the actuator test, the VFD will display all of
its characters at once, then step through each char-
acter segment individually during the VFD portion of
the test to confirm the functionality of the VFD and
the cluster control circuitry.
The PCM continually monitors the vehicle speed
sensor, then sends the proper distance messages to
the instrument cluster. For further diagnosis of the
odometer/trip odometer or the instrument cluster cir-
cuitry that controls these functions, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
vehicle speed sensor, the PCM, the CCD data bus, or
the message inputs to the instrument cluster that
control the odometer/trip odometer, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
OIL PRESSURE GAUGE
DESCRIPTION
An oil pressure gauge is standard equipment on all
instrument clusters. The oil pressure gauge is located
in the upper right quadrant of the instrument clus-
ter, above the fuel gauge. The oil pressure gauge con-
sists of a movable gauge needle or pointer controlled
by the instrument cluster circuitry and a fixed 90
degree scale on the cluster overlay that reads left-to-
right either from 0 kPa (0 psi) to 758 kPa (110 psi).
An International Control and Display Symbol icon for
ªEngine Oilº is located on the cluster overlay, directly
below the highest graduation of the gauge scale. The
oil pressure gauge graphics are white against a black
field except for a single red graduation at the lowend of the gauge scale, making them clearly visible
within the instrument cluster in daylight. When illu-
minated from behind by the panel lamps dimmer
controlled cluster illumination lighting with the exte-
rior lamps turned On, the white graphics appear
blue-green and the red graphics appear red. The
orange gauge needle is internally illuminated. Gauge
illumination is provided by replaceable incandescent
bulb and bulb holder units located on the instrument
cluster electronic circuit board. The oil pressure
gauge is serviced as a unit with the instrument clus-
ter.
OPERATION
The oil pressure gauge gives an indication to the
vehicle operator of the engine oil pressure. This
gauge is controlled by the instrument cluster circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Chrysler
Collision Detection (CCD) data bus. The oil pressure
gauge is an air core magnetic unit that receives bat-
tery current on the instrument cluster electronic cir-
cuit board through the fused ignition switch output
(st-run) circuit whenever the ignition switch is in the
On or Start positions. The cluster is programmed to
move the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Engine Oil Pressure Message- The instru-
ment cluster circuitry restricts the oil pressure gauge
needle operation in order to provide readings that
are consistent with customer expectations. Each time
the cluster receives a message from the PCM indicat-
ing the engine oil pressure is between about 6.9 kPa
(1 psi) and 137.9 kPa (20 psi) for gasoline engines, or
55 kPa (8 psi) and 58.6 kPa (8.5 psi) for diesel
engines, the cluster holds the gauge needle at a point
about 11 degrees above the low end of normal incre-
ment on the gauge scale. Each time the cluster
receives a message from the PCM indicating the
engine oil pressure is between about 517.1 kPa (75
psi) and 755 kPa (109.5 psi) for gasoline engines, or
551.6 kPa (80 psi) and 755 kPa (109.5 psi) for diesel
engines, the cluster holds the gauge needle at a point
about 7.4 degrees below the high end of normal
increment on the gauge scale. When the cluster
receives messages from the PCM indicating the
engine oil pressure is between about 137.9 kPa (20
psi) and 517.1 kPa (75 psi) for gasoline engines, or
58.6 kPa (8.5 psi) and 551.6 kPa (80 psi) for diesel
engines], the gauge needle is moved to the actual
pressure position on the gauge scale.
BR/BEINSTRUMENT CLUSTER 8J - 25
ODOMETER (Continued)

remains illuminated until the cluster receives an
overdrive off lamp-off message from the PCM, 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 indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The PCM continually monitors the overdrive off
switch to determine the proper outputs to the auto-
matic transmission, then sends the proper messages
to the instrument cluster. For further diagnosis of
the overdrive off indicator or the instrument cluster
circuitry that controls the LED, (Refer to 8 - ELEC-
TRICAL/INSTRUMENT CLUSTER - DIAGNOSIS
AND TESTING). For proper diagnosis of the over-
drive control system, the PCM, the CCD data bus, or
the message inputs to the instrument cluster that
control the overdrive off indicator, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
SEATBELT INDICATOR
DESCRIPTION
A seatbelt indicator is standard equipment on all
instrument clusters. The seatbelt indicator is located
near the lower edge of the instrument cluster overlay,
to the right of center. The seatbelt indicator consists
of a stencilled cutout of the International Control and
Display Symbol icon for ªSeat Beltº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. A red
lens behind the cutout in the opaque layer of the
overlay causes the icon to appear in red through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by a Light Emitting
Diode (LED) soldered onto the instrument cluster
electronic circuit board. The seatbelt indicator is ser-
viced as a unit with the instrument cluster.
OPERATION
The seatbelt indicator gives an indication to the
vehicle operator of the status of the driver side front
seatbelt buckle. This indicator is controlled by a tran-
sistor on the instrument cluster circuit board based
upon the cluster programming, and a hard wired
input from the seatbelt switch in the driver side front
seatbelt through the seat belt switch sense circuit.
The seatbelt indicator Light Emitting Diode (LED)
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (st-run) circuit whenever the ignitionswitch is in the On or Start positions; therefore, the
indicator will always be off when the ignition switch
is in any position except On or Start. The LED only
illuminates when it is switched to ground by the
instrument cluster transistor. The instrument cluster
will turn on the seatbelt indicator for the following
reasons:
²Seatbelt Reminder Function- Each time the
cluster receives a battery current input on the fused
ignition switch output (st-run) circuit, the indicator
will be illuminated as a seatbelt reminder for about
seven seconds, or until the ignition switch is turned
to the Off position, whichever occurs first. This
reminder function will occur regardless of the status
of the seatbelt switch input to the cluster.
²Driver Side Front Seatbelt Not Buckled-
Following the seatbelt reminder function, each time
the cluster receives a ground input on the seat belt
switch sense circuit (seatbelt switch closed - seatbelt
unbuckled) with the ignition switch in the Start or
On positions, the indicator will be illuminated. The
seatbelt indicator remains illuminated until the seat
belt switch sense input to the cluster is an open cir-
cuit (seatbelt switch opened - seatbelt buckled), 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 indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the LED and the cluster
control circuitry.
The seatbelt switch input to the instrument cluster
circuitry can be diagnosed using conventional diag-
nostic tools and methods. For further diagnosis of the
seatbelt indicator or the instrument cluster circuitry
that controls the LED, (Refer to 8 - ELECTRICAL/
INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING).
SERVICE REMINDER
INDICATOR
DESCRIPTION
A Service Reminder Indicator (SRI) is standard
equipment on all instrument clusters. However, on
vehicles not equipped with certain optional heavy
duty emission cycle gasoline engines, this indicator is
electronically disabled. The SRI is located near the
lower edge of the instrument cluster overlay, to the
left of center. The SRI consists of a stencilled cutout
of the words ªMAINT REQDº in the opaque layer of
the instrument cluster overlay. The dark outer layer
of the overlay prevents the indicator from being
clearly visible when it is not illuminated. An amber
lens behind the cutout in the opaque layer of the
BR/BEINSTRUMENT CLUSTER 8J - 27
OVERDRIVE OFF INDICATOR (Continued)

OPERATION
The upshift indicator gives an indication to the
vehicle operator when the transmission should be
shifted to the next highest gear in order to achieve
the best fuel economy. 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 Powertrain
Control Module (PCM) over the Chrysler Collision
Detection (CCD) data bus. The upshift indicator bulb
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (st-run) circuit whenever the ignition
switch is in the On or Start positions; therefore, the
lamp will always be off when the ignition switch is in
any position except On or Start. The bulb only illu-
minates when it is provided a path to ground by the
instrument cluster transistor. On models not
equipped with a manual transmission, the incandes-
cent bulb and bulb holder unit are not installed at
the factory when the vehicle is built. The instrument
cluster will turn on the upshift indicator for the fol-
lowing reasons:
²Upshift Lamp-On Message- Each time the
cluster receives an upshift lamp-on message from the
PCM indicating the engine speed and load conditions
are right for a transmission upshift to occur, the
upshift indicator is illuminated. The indicator
remains illuminated until the cluster receives an
upshift lamp-off message from the PCM or until the
ignition switch is turned to the Off position, which-
ever occurs first. The PCM will normally send an
upshift lamp-off message three to five seconds after a
lamp-on message, if an upshift is not performed. The
indicator will then remain off until the vehicle stops
accelerating and is brought back into the range of
indicator operation, or until the transmission is
shifted into another gear.
²Actuator Test- Each time the cluster is put
through the actuator test, the indicator will be
turned on during the bulb check portion of the test to
confirm the functionality of the indicator and the
cluster control circuitry.
The PCM continually monitors the engine speed
and load conditions to determine the proper fuel and
ignition requirements. The PCM then sends the
proper messages to the instrument cluster. If the
upshift indicator fails to light during normal vehicle
operation, replace the bulb with a known good unit.
For further diagnosis of the upshift indicator or the
instrument cluster circuitry that controls the indica-
tor, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). For
proper diagnosis of the PCM, the CCD data bus, or
the message inputs to the instrument cluster that
control the upshift indicator, a DRBIIItscan tool isrequired. Refer to the appropriate diagnostic infor-
mation.
VOLTAGE GAUGE
DESCRIPTION
A voltage gauge is standard equipment on all
instrument clusters. The voltage gauge is located in
the upper left quadrant of the instrument cluster,
above the temperature gauge. The voltage gauge con-
sists of a movable gauge needle or pointer controlled
by the instrument cluster circuitry and a fixed 90
degree scale on the cluster overlay that reads left-to-
right from 8 volts to 18 volts. An International Con-
trol and Display Symbol icon for ªBattery Charging
Conditionº is located directly below the lowest grad-
uation of the gauge scale. The voltage gauge graphics
are white against a black field except for a single red
graduation at each end of the gauge scale, making
them clearly visible within the instrument cluster in
daylight. When illuminated from behind by the panel
lamps dimmer controlled cluster illumination lighting
with the exterior lamps turned On, the white graph-
ics appear blue-green and the red graphics appear
red. The orange gauge needle is internally illumi-
nated. Gauge illumination is provided by replaceable
incandescent bulb and bulb holder units located on
the instrument cluster electronic circuit board. The
voltage gauge is serviced as a unit with the instru-
ment cluster.
OPERATION
The voltage gauge gives an indication to the vehi-
cle operator of the electrical system voltage. This
gauge is controlled by the instrument cluster circuit
board based upon the cluster programming and elec-
tronic messages received by the cluster from the
Powertrain Control Module (PCM) over the Chrysler
Collision Detection (CCD) data bus. The voltage
gauge is an air core magnetic unit that receives bat-
tery current on the instrument cluster electronic cir-
cuit board through the fused ignition switch output
(st-run) circuit whenever the ignition switch is in the
On or Start positions. The cluster is programmed to
move the gauge needle back to the low end of the
scale after the ignition switch is turned to the Off
position. The instrument cluster circuitry controls
the gauge needle position and provides the following
features:
²Charge Fail Message- Each time the cluster
receives a message from the PCM indicating a charge
fail condition (system voltage is 10.8 volts or lower),
the gauge needle is moved to the 8 volt graduation
on the gauge scale and the check gauges indicator is
illuminated. The gauge needle remains on the 8 volt
BR/BEINSTRUMENT CLUSTER 8J - 33
UPSHIFT INDICATOR (Continued)