sensor DODGE RAM 2002 Service Manual PDF

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)

²Engine Oil Pressure Low Message- Each
time the cluster receives a message from the PCM
indicating the engine oil pressure is below about 6.9
kPa (1 psi) for gasoline engines, or 55 kPa (8 psi) for
diesel engines, the gauge needle is moved to the 0
kPa (0 psi) graduation at the far left (low) end of the
gauge scale, the check gauges indicator is illumi-
nated, and a single chime tone is generated. The
gauge needle remains at the low end of the scale and
the check gauges indicator remains illuminated until
the cluster receives a message from the PCM indicat-
ing that the engine oil pressure is above about 6.9
kPa (1 psi) for gasoline engines, or 55 kPa (8 psi) for
diesel engines, or until the ignition switch is turned
to the Off position, whichever occurs first. The clus-
ter will only turn the check gauges indicator lamp on
in response to an engine oil pressure low message if
the engine speed message is greater than zero.
²Engine Oil Pressure High Message- Each
time the cluster receives a message from the PCM
indicating the engine oil pressure is above about 755
kPa (109.5 psi) for gasoline or diesel engines, the
gauge needle is moved to the 758.4 kPa (110 psi)
graduation at the far right (high) end of the gauge
scale. The gauge needle remains at the high end of
the scale until the cluster receives a message from
the PCM indicating that the engine oil pressure is
below about 755 kPa (109.5 psi) for gasoline or diesel
engines, or until the ignition switch is turned to the
Off position, whichever occurs first.
²Message Failure- If the cluster fails to receive
an engine oil pressure 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 oil pres-
sure sensor to determine the engine oil pressure. The
PCM then sends the proper engine oil pressure mes-
sages to the instrument cluster. For further diagnosis
of the oil pressure 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 low oil pressure
gauge reading, it may indicate that the engine or the
engine oiling system requires service. For proper
diagnosis of the engine oil pressure sensor, the PCM,
the CCD data bus, or the message inputs to the
instrument cluster that control the oil pressuregauge, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
OVERDRIVE OFF INDICATOR
DESCRIPTION
An overdrive off indicator is standard equipment
on all instrument clusters. However, on vehicles not
equipped with the optional overdrive automatic
transmission, this indicator is electronically disabled.
The overdrive off indicator is located near the lower
edge of the instrument cluster overlay, to the right of
center. The overdrive off indicator consists of a sten-
cilled cutout of the words ªO/D OFFº 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 ªO/D OFFº text to appear in
amber through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by a Light Emitting Diode (LED) soldered
onto the instrument cluster electronic circuit board.
The overdrive off indicator is serviced as a unit with
the instrument cluster.
OPERATION
The overdrive off indicator gives an indication to
the vehicle operator when the Off position of the
overdrive off switch has been selected, disabling the
electronically controlled overdrive feature of the auto-
matic transmission. 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 overdrive off 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
overdrive off indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the overdrive off indicator
is illuminated for about two seconds as a bulb test.
²Overdrive Off Lamp-On Message- Each time
the cluster receives an overdrive off lamp-on message
from the PCM indicating that the Off position of the
overdrive off switch has been selected, the overdrive
off indicator will be illuminated. The indicator
8J - 26 INSTRUMENT CLUSTERBR/BE
OIL PRESSURE GAUGE (Continued)

overlay causes the ªMAINT REQDº text to appear in
amber through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by a Light Emitting Diode (LED) soldered
onto the instrument cluster electronic circuit board.
The SRI is serviced as a unit with the instrument
cluster.
OPERATION
The Service Reminder Indicator (SRI) gives an
indication to the vehicle operator when engine emis-
sions maintenance procedures should be performed.
This indicator is controlled by a transistor on 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 SRI Light Emitting Diode (LED)
receives battery current on the instrument cluster
electronic circuit board through the fused ignition
switch output (st-run) circuit whenever the ignition
switch is in the On or Start positions; therefore, the
LED will always be off when the ignition switch is in
any position except On or Start. The LED only illu-
minates when it is provided a path to ground by the
instrument cluster transistor. The instrument cluster
will turn on the SRI for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the SRI is illuminated for
about two seconds as a bulb test.
²Service Required Lamp-On Message- Each
time the cluster receives a service required lamp-on
message from the PCM indicating that an emissions
maintenance interval has been reached, the SRI will
be illuminated. The indicator remains illuminated
until the cluster receives a service required 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 SRI 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 vehicle speed
sensor to determine the distance the vehicle has been
driven, then sends the proper messages to the instru-
ment cluster. Once the SRI has been illuminated and
the required emissions maintenance procedures have
been completed, the PCM must be reset using a
DRBIIItscan tool before it will send the proper ser-
vice required lamp-off message to the instrument
cluster. Refer to the appropriate diagnostic informa-
tion. For further diagnosis of the SRI or the instru-
ment cluster circuitry that controls the LED, (Refer
to 8 - ELECTRICAL/INSTRUMENT CLUSTER -
DIAGNOSIS AND TESTING). For proper diagnosisof the PCM, the CCD data bus, or the message
inputs to the instrument cluster that control the SRI,
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
SHIFT INDICATOR (TRANSFER
CASE)
DESCRIPTION
A four-wheel drive indicator is standard equipment
on all instrument clusters. However, on vehicles not
equipped with the optional four-wheel drive system,
this indicator is mechanically disabled. The four-
wheel drive indicator is located near the lower edge
of the instrument cluster overlay, to the right of cen-
ter. The four-wheel drive indicator consists of a sten-
cilled cutout of the text ª4WDº 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 ª4WDº text to appear in amber
through the translucent outer layer of the overlay
when the indicator is illuminated from behind by a
Light Emitting Diode (LED) soldered onto the instru-
ment cluster electronic circuit board. The four-wheel
drive indicator is serviced as a unit with the instru-
ment cluster.
OPERATION
The four-wheel drive indicator lamp gives an indi-
cation to the vehicle operator that a four-wheel drive
operating mode is engaged. The indicator will be illu-
minated when either high range (4H) or low range
(4L) have been selected with the transfer case shift
lever. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon the
cluster programming, and a hard wired input from
the four-wheel drive switch on the front axle discon-
nect housing. The four-wheel drive indicator Light
Emitting Diode (LED) receives battery current on the
instrument cluster electronic circuit board through
the fused ignition switch output (st-run) circuit
whenever the ignition switch is in the On or Start
positions; therefore, the lamp 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 four-wheel drive switch is connected in series
between ground and the four-wheel drive switch
sense input to the instrument cluster. For further
information on the transfer case and the transfer
case operating ranges, (Refer to 21 - TRANSMIS-
SION/TRANSAXLE/TRANSFER CASE - OPERA-
TION. For further information on the front axle
8J - 28 INSTRUMENT CLUSTERBR/BE
SERVICE REMINDER INDICATOR (Continued)

illumination lighting with the exterior lamps turned
On, the white graphics appear blue-green, while the
red graphics still appear red. The orange gauge nee-
dle is internally illuminated. Gauge illumination is
provided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The speedometer is serviced as a
unit with the instrument cluster.
OPERATION
The speedometer gives an indication to the vehicle
operator of the vehicle road speed. This gauge is con-
trolled by the instrument cluster circuit board based
upon the cluster programming and electronic mes-
sages received by the cluster from the Powertrain
Control Module (PCM) over the Chrysler Collision
Detection (CCD) data bus. The speedometer is an air
core magnetic unit that 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. 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:
²Message Failure- If the cluster fails to receive
a speedometer message, it will hold the gauge needle
at the last indication for about four seconds, or until
the ignition switch is turned to the Off position,
whichever occurs first. If a new speedometer message
is not received after about four seconds, the gauge
needle will return to the far left (low) end of the
scale.
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 vehicle speed
sensor to determine the vehicle road speed, then
sends the proper vehicle speed messages to the
instrument cluster. For further diagnosis of the
speedometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). 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
speedometer, a DRBIIItscan tool is required. Refer
to the appropriate diagnostic information.
TACHOMETER
DESCRIPTION
A tachometer is standard equipment on all instru-
ment clusters. The tachometer is located just to the
left of the speedometer near the center of the instru-
ment cluster. The tachometer consists of a movable
gauge needle or pointer controlled by the instrument
cluster circuitry and a fixed 210 degree scale on the
gauge dial face that reads left-to-right either from 0
to 6 for gasoline engines, or from 0 to 4 for diesel
engines. The text ªRPM X 1000º imprinted on the
cluster overlay directly below the hub of the tachom-
eter needle identifies that each number on the
tachometer scale is to be multiplied times 1000 rpm.
The gauge scale of the gasoline engine tachometer is
red lined at 5000 rpm, while the diesel engine
tachometer is red lined at 3375 rpm. The diesel
engine tachometer also includes text that specifies
ªDIESEL FUEL ONLYº located just above the hub of
the tachometer needle. The tachometer graphics are
white and red against a black field, making them
clearly visible within the instrument cluster in day-
light. 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, while the red graphics still
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 tachometer is serviced as a unit with the
instrument cluster.
OPERATION
The tachometer gives an indication to the vehicle
operator of the engine speed. This gauge is controlled
by 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 tachometer is an air core mag-
netic unit that receives battery current on the instru-
ment cluster electronic circuit board through the
fused ignition switch output (st-run) circuit whenever
the ignition switch is in the On or Start positions.
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:
²Message Failure- If the cluster fails to receive
an engine speed message, it will hold the gauge nee-
dle at the last indication for about four seconds, or
until the ignition switch is turned to the Off position,
whichever occurs first. If a new engine speed mes-
8J - 30 INSTRUMENT CLUSTERBR/BE
SPEEDOMETER (Continued)

sage is not received after about four seconds, the
gauge needle will return to the far left (low) end of
the scale.
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 crankshaft posi-
tion sensor to determine the engine speed, then
sends the proper engine speed messages to the
instrument cluster. For further diagnosis of the
tachometer or the instrument cluster circuitry that
controls the gauge, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the crankshaft position
sensor, the PCM, the CCD data bus, or the message
inputs to the instrument cluster that control the
tachometer, a DRBIIItscan tool is required. Refer to
the appropriate diagnostic information.
TRANS OVERTEMP
INDICATOR
DESCRIPTION
A transmission over-temperature indicator lamp is
standard equipment on all instrument clusters. How-
ever, on vehicles not equipped with the optional auto-
matic transmission, this indicator is electronically
disabled. The transmission over-temperature indica-
tor is located near the lower edge of the instrument
cluster overlay, to the left of center. The transmission
over-temperature indicator consists of a stencilled
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
lens 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 over-
lay when the indicator is illuminated from behind by
a Light Emitting Diode (LED) soldered onto the
instrument cluster electronic circuit board. The
transmission over-temperature indicator is serviced
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 the
cluster programming and electronic messagesreceived by the cluster from the Powertrain Control
Module (PCM) over the Chrysler Collision Detection
(CCD) data bus. The transmission over-temperature
indicator Light Emitting Diode (LED) 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; 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 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 lamp remains illuminated until
the cluster receives a trans over-temp lamp-off mes-
sage 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 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 transmission
temperature sensor to determine the transmission
operating condition, then sends the proper 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
transmission cooling system are being overloaded or
that they require service. For further diagnosis of the
transmission over-temperature indicator or the
instrument cluster circuitry that controls the LED,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). For proper
diagnosis of the transmission temperature sensor, the
PCM, the CCD data bus, or the 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.
BR/BEINSTRUMENT CLUSTER 8J - 31
TACHOMETER (Continued)

graduation and the check gauges indicator remains
illuminated until the cluster receives a message from
the PCM indicating there is no charge fail condition
(system voltage is 10.9 volts or higher, but lower
than 16.7 volts), or until the ignition switch is turned
to the Off position, whichever occurs first. On models
equipped with the optional diesel engine, the instru-
ment cluster is programmed to support the voltmeter
gauge needle above the low end of normal graduation
and suppress the check gauges indicator operation
until ten seconds after the engine intake manifold air
heater has completed its cycle.
²Voltage High Message- Each time the cluster
receives a message from the PCM indicating a volt-
age high condition (system voltage is 16.7 volts or
higher), the gauge needle is moved to the 18 volt
graduation on the gauge scale and the check gauges
indicator is illuminated. The gauge needle remains
on the 18 volt graduation and the check gauges indi-
cator remains illuminated until the cluster receives a
message from the PCM indicating there is no voltage
high condition (system voltage is 16.6 volts or lower,
but higher than 10.9 volts), or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Message Failure- If the cluster fails to receive
a system voltage message, it will hold the gauge nee-
dle at the last indication until a new message 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 system voltage
to control the generator output. The PCM then sends
the proper system voltage messages to the instru-
ment cluster. For further diagnosis of the voltage
gauge or the instrument cluster circuitry that con-
trols the gauge, (Refer to 8 - ELECTRICAL/INSTRU-
MENT CLUSTER - DIAGNOSIS AND TESTING). If
the instrument cluster turns on the check gauges
indicator due to a charge fail or voltage high condi-
tion, it may indicate that the charging system
requires service. For proper diagnosis of the charging
system, the CCD data bus, or the message inputs to
the instrument cluster that control the voltage
gauge, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.WAIT-TO-START INDICATOR
DESCRIPTION
A wait-to-start indicator is standard equipment on
all instrument clusters, but is only functional in vehi-
cles equipped with an optional diesel engine. The
wait-to-start indicator is located near the lower edge
of the instrument cluster overlay, to the right of cen-
ter. The wait-to-start indicator consists of a stenciled
cutout of the text ªWAIT TO STARTº in the opaque
layer of the cluster overlay. The dark outer layer of
the overlay prevents the indicator from being clearly
visible when it is not illuminated. A red lens located
behind the cutout causes the ªWAIT TO STARTº text
to appear in red through the translucent outer layer
of the overlay when the indicator is illuminated from
behind by a Light Emitting Diode (LED) that is sol-
dered 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 diesel engine intake
air heater is energized in its preheat operating mode.
This indicator is controlled by a hard wired input to
the instrument cluster from the Engine Control Mod-
ule (ECM). The wait-to-start indicator Light Emitting
Diode (LED) receives battery current on the instru-
ment cluster electronic circuit board through the
fused ignition switch output (st-run) circuit whenever
the ignition switch is in the On or Start positions;
therefore, the lamp will always be off when the igni-
tion switch is in any position except On or Start. The
indicator LED only illuminates when it is switched to
ground by the input from the ECM. The ECM will
turn on the wait-to-start indicator by pulling the
wait-to-start indicator driver circuit to ground each
time the ignition switch is turned to the On or Start
positions. The indicator then remains illuminated
until the ECM detects that the air within the intake
manifold is the proper temperature to ensure reliable
and efficient engine starting, until the ECM detects
that the engine is running, or until the ignition
switch is turned to the Off position, whichever occurs
first.
The ECM continually monitors the intake manifold
air temperature sensor, the Manifold Absolute Pres-
sure (MAP) sensor, and many other vehicle condi-
tions to determine when the wait-to-start indicator
should be illuminated. For proper diagnosis of the
wait-to-start indicator, the ECM, or the inputs the
ECM uses to control the wait-to-start indicator oper-
ation, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
8J - 34 INSTRUMENT CLUSTERBR/BE
VOLTAGE GAUGE (Continued)

INDICATOR DOES NOT ILLUMINATE WITH WASHER
RESERVOIR EMPTY
(1) Disconnect and isolate the battery negative
cable. Disconnect the headlamp and dash wire har-
ness connector for the washer fluid level switch from
the washer fluid level switch connector receptacle.
Check for continuity between the ground circuit cav-
ity of the headlamp and dash wire harness connector
for the washer fluid level switch and a good ground.
There should be continuity. If OK, go to Step 2. If not
OK, repair the open ground circuit to ground (G100)
as required.
(2) Remove the instrument cluster from the instru-
ment panel. Check for continuity between the washer
fluid switch sense circuit cavities of the headlamp
and dash wire harness connector for the washer fluid
level switch and the instrument panel wire harness
connector (Connector C2) for the instrument cluster.
If OK, replace the faulty washer fluid level switch. If
not OK, repair the open washer fluid switch sense
circuit between the washer fluid level switch and the
instrument cluster as required.
INDICATOR STAYS ILLUMINATED WITH WASHER
RESERVOIR FULL
(1) Disconnect and isolate the battery negative
cable. Disconnect the headlamp and dash wire har-
ness connector for the washer fluid level switch from
the washer fluid level switch connector receptacle.
Check for continuity between the ground circuit ter-
minal and the washer fluid switch sense terminal in
the washer fluid level switch connector receptacle.
There should be no continuity. If OK, go to Step 2. If
not OK, replace the faulty washer fluid level switch.
(2) Remove the instrument cluster from the instru-
ment panel. Check for continuity between the washer
fluid switch sense circuit cavity of the headlamp and
dash wire harness connector for the washer fluid
level switch and a good ground. There should be no
continuity. If not OK, repair the shorted washer fluid
switch sense circuit between the washer fluid level
switch and the instrument cluster as required.
WATER-IN-FUEL INDICATOR
DESCRIPTION
A water-in-fuel indicator is standard equipment on
all instrument clusters, but is only functional in vehi-
cles equipped with an optional diesel engine. The
water-in-fuel indicator is located near the lower edge
of the instrument cluster overlay, to the left of center.
The water-in-fuel indicator consists of a stencilled
cutout of the text 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 redlens located behind the cutout causes the ªWATER
IN FUELº text to appear in red through the translu-
cent outer layer of the overlay when the indicator is
illuminated from behind by a Light Emitting Diode
(LED) 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 the water accumulated in
the diesel engine fuel filter/separator filter bowl
requires draining. 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 Chrysler Collision Detection
(CCD) data bus. The water-in-fuel indicator Light
Emitting Diode (LED) receives battery current on the
instrument cluster electronic circuit board through
the fused ignition switch output (st-run) circuit
whenever the ignition switch is in the On or Start
positions; therefore, the 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 transis-
tor. 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 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, the indicator will be illuminated. The
indicator remains illuminated until the cluster
receives a water-in-fuel lamp-off message from the
ECM 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 ECM continually monitors the water-in-fuel
sensor, then sends the proper messages to the instru-
ment cluster. For further diagnosis of the water-in-
fuel indicator or the instrument cluster circuitry that
controls the indicator, (Refer to 8 - ELECTRICAL/IN-
STRUMENT CLUSTER - DIAGNOSIS AND TEST-
ING). For proper diagnosis of the water-in-fuel
sensor, the ECM, the CCD data bus, or the message
inputs to the instrument cluster that control the
water-in-fuel indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic
information.
8J - 36 INSTRUMENT CLUSTERBR/BE
WASHER FLUID INDICATOR (Continued)

(9) Disconnect the instrument panel wire harness
connector for the multi-function switch from the
switch connector receptacle. Check for continuity
between the hazard flasher signal circuit cavities in
the JB receptacle for the combination flasher and the
instrument panel wire harness connector for the
multi-function switch. There should be continuity. If
OK, go to Step 10. If not OK, repair the open hazard
flasher signal circuit between the JB and the multi-
function switch as required.
(10) Check for continuity between the flasher out-
put circuit cavities of the JB receptacle for the com-
bination flasher and in the instrument panel wire
harness connector for the multi-function switch.
There should be continuity. If OK, test the multi-
function switch. (Refer to 8 - ELECTRICAL/LAMPS/
LIGHTING - EXTERIOR/MULTI-FUNCTION
SWITCH - DIAGNOSIS AND TESTING). If not OK,
repair the open flasher output circuit between the JB
and the multi-function switch as required.
SPECIFICATIONS
EXTERIOR LAMPS
LAMP BULB
Back-up 3157
Cargo 921
Center High Mounted
Stop921
Clearance Roof Mounted 168
Fog Lamps 896
Headlamp - SLT 9004LL
Headlamp - Sport Low
Beam9007
Headlamp - Sport High
Beam9004LL
License Plate w/o
Bumper1155
License Plate -Step
Bumper168
Park/Turn Signal 3157NA
Snow Plow Control 161
Tail/Brake/Turn Signal 3157
Tail/Brake/Cab - Chassis 1157
Underhood 105
SPECIAL TOOLS
HEADLAMP ALIGNMENT
BRAKE LAMP SWITCH
DESCRIPTION
The plunger type brake lamp switch is mounted on
a bracket attached to the brake pedal support under
the instrument panel.
CAUTION: The switch can only be adjusted during
initial installation. If the switch is not adjusted prop-
erly a new switch must be installed.
OPERATION
The brake lamp switch is used for the brake lamp,
speed control brake sensor circuits and electronic
brake distribution (EBD). The brake lamp circuit is
open until the plunger is depressed. The speed con-
trol and brake sensor circuits are closed until the
plunger is depressed.
When the brake light switch is activated, the Pow-
ertrain Control Module (PCM) receives an input indi-
cating that the brakes are being applied. After
receiving this input, the PCM maintains idle speed to
a scheduled rpm through control of the Idle Air Con-
trol (IAC) motor. The brake switch input is also used
to disable vent and vacuum solenoid output signals
to the speed control servo.
Vehicles equipped with the speed control option use
a dual function brake lamp switch. The PCM moni-
tors the state of the dual function brake lamp switch.
Refer to the Brake section for more information on
brake lamp switch service and adjustment proce-
dures.
Headlamp Aiming Kit C-4466±A
8L - 4 LAMPS/LIGHTING - EXTERIORBR/BE
LAMPS/LIGHTING - EXTERIOR (Continued)

INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Position the combination flasher in the proper
receptacle of the Junction Block (JB).
(2) Align the terminals of the combination flasher
with the terminal cavities in the JB receptacle for
the flasher.
(3) Push in firmly and evenly on the combination
flasher until the terminals are fully seated in the ter-
minal cavities of the JB receptacle for the flasher.
(4) Reinstall the fuse access panel by snapping it
onto the left outboard end of the instrument panel.
(5) Reconnect the battery negative cable.
DAYTIME RUNNING LAMP
MODULE
DESCRIPTION
The Daytime Running Lights (Headlamps) System
is installed on vehicles manufactured for sale in Can-
ada only. A separate module, mounted on the cowl,
controls the DRL.
OPERATION
The headlamps are illuminated when the ignition
switch is turned to the ON position. The DRL module
receives a vehicle-moving signal from the vehicle
speed sensor. This provides a constanthead-
lamps-oncondition as long as the vehicle is moving.
The lamps are illuminated at less than 50 percent of
normal intensity.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disengage wire connector from DRLM (Fig. 8).
(3) Remove screws attaching DRLM to left front
inner fender panel.
(4) Separate DRLM from fender.
INSTALLATION
(1) Position DRLM on fender.
(2) Install screws attaching DRLM to left front
inner fender panel.
(3) Engage wire connector to DRLM.
(4) Connect the battery negative cable.
Fig. 7 Junction Block
1 - JUNCTION BLOCK
2 - FUSE ACCESS PANEL
Fig. 8 Daytime Running Lamp Module (DRLM)
1 - HEADLAMP AND DASH WIRING HARNESS
2 - LEFT FENDER SIDE SHIELD
3 - DAYTIME RUNNING LAMP MODULE
BR/BELAMPS/LIGHTING - EXTERIOR 8L - 9
COMBINATION FLASHER (Continued)

MESSAGE SYSTEMS
TABLE OF CONTENTS
page page
OVERHEAD CONSOLE
DESCRIPTION..........................1
STANDARD PROCEDURE
STANDARD PROCEDURE - COMPASS
CALIBRATION.........................4
STANDARD PROCEDURE - COMPASS
VARIATION ADJUSTMENT................4
STANDARD PROCEDURE - COMPASS
DEMAGNETIZING......................5
REMOVAL
OVERHEAD CONSOLE REMOVAL.........6
DISASSEMBLY
OVERHEAD CONSOLE DISASSEMBLY......7
ASSEMBLY
OVERHEAD CONSOLE ASSEMBLY........8
INSTALLATION
OVERHEAD CONSOLE INSTALLATION......8SPECIAL TOOLS
OVERHEAD CONSOLE SPECIAL TOOL.....9
COMPASS/MINI-TRIP COMPUTER
DESCRIPTION..........................9
OPERATION............................9
DIAGNOSIS AND TESTING - COMPASS
MINI-TRIP COMPUTER.................10
REMOVAL.............................11
INSTALLATION.........................11
AMBIENT TEMP SENSOR
DESCRIPTION.........................12
OPERATION...........................12
DIAGNOSIS AND TESTING - AMBIENT
TEMPERATURE SENSOR...............12
REMOVAL.............................12
INSTALLATION.........................13
OVERHEAD CONSOLE
DESCRIPTION
Three different overhead console units are avail-
able factory-installed options on this model, base,
premium and premium with vehicle theft security.
The base overhead console unit features a garage
door opener storage bin, a sunglasses storage bin and
two reading and courtesy lamps. The premium over-
head console has all of the features of the base unit,
but adds a compass mini-trip computer and/or vehi-
cle theft security LED. See the owner's manual in
the vehicle glove box for more information on the fea-
tures, use and operation of all of the overhead con-
sole components and systems. Refer toOverhead
Consolein the Contents of Wiring Diagrams for
complete circuit diagrams.
The premium overhead console (Fig. 1) includes
two front-mounted reading and courtesy lamps, a
garage door opener storage bin, and a sunglasses
storage bin. The premium overhead console includesa compass mini-trip computer. The base overhead
console uses the same overhead console housing, but
has a computer cover plug installed in place of the
compass mini-trip computer display module lens and
push buttons.
The rear of the overhead console is secured to two
rear mounting holes in the inner roof panel by two
plastic hook formations that are integral to the over-
head console housing. The front of the overhead con-
sole is secured to the two front mounting holes of the
inner roof panel by two plastic latches that are inte-
gral to the overhead console housing. A single electri-
cal connection joins the overhead console wire
harness to the roof wire harness for both the base
and premium overhead console units.
Following are general descriptions of the major
components used in the overhead console. See the
owner's manual in the vehicle glove box for more
information on the use and operation of the various
overhead console features.
BR/BEMESSAGE SYSTEMS 8M - 1