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Dodge Dakota (R1). Manual - part 324

bulb holder unit located on the instrument cluster
electronic circuit board. The high beam indicator is
serviced 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 the Central Timer Module (CTM)
through the high beam indicator driver circuit input
to the cluster based upon a control signal to the CTM
from the headlamp beam select switch. The head-
lamp beam select switch is integral to the multi-func-
tion switch on the left side of the steering column.
The high beam indicator bulb receives battery cur-
rent on the instrument cluster electronic circuit
board through a fused B(+) circuit at all times; there-
fore, the indicator remains operational regardless of
the ignition switch position. The indicator only illu-
minates when it is provided with a path to ground by
the CTM. The high beam indicator can be diagnosed
using conventional diagnostic tools and methods. For
proper diagnosis of the CTM and the inputs to the
CTM that control the high beam indicator driver cir-
cuit, a DRBIII

t scan tool is required. Refer to the

appropriate diagnostic information.

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
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 driver cir-
cuit. Refer to the appropriate wiring information. The
wiring 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 1 - 15 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 1 - 15 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) 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. Disconnect the instrument panel wire harness
connector (Connector C1) for the Central Timer Mod-
ule (CTM) from the CTM connector receptacle. Check
for continuity between the high beam indicator driver
circuit cavities of the instrument panel wire harness
connector (Connector C1) for the CTM and the
instrument panel wire harness connector (Connector
C1) for the instrument cluster. There should be con-
tinuity. If OK, go to Step 5. If not OK, repair the
open high beam indicator driver circuit between the
instrument cluster and the CTM as required.

(5) Reinstall

the

instrument

cluster

onto

the

instrument panel. Reconnect the battery negative
cable. Install a jumper wire between the high beam
indicator driver circuit cavity of the instrument panel
wire harness connector (Connector C1) for the CTM
and a good ground. The indicator should illuminate.
If OK, diagnose the CTM and its inputs using a
DRBIII

t scan tool. Refer to the appropriate diagnos-

tic procedures. If not OK, replace the faulty high
beam indicator bulb and bulb holder unit.

INDICATOR STAYS ILLUMINATED WITH HIGH BEAMS NOT
SELECTED

(1) Disconnect and isolate the battery negative

8J - 22

INSTRUMENT CLUSTER

HIGH BEAM INDICATOR (Continued)

ground. There should be no continuity. If OK, diag-
nose the CTM and its inputs using a DRBIII

t scan

tool. Refer to the appropriate diagnostic procedures.
If not OK, repair the shorted high beam indicator
driver circuit between the CTM and the instrument
cluster as required.

LOW FUEL INDICATOR

DESCRIPTION

A low fuel indicator is standard equipment on all

instrument clusters. The low fuel indicator is located
in the Information Center area of the instrument
cluster overlay, to the left of center. The low fuel indi-
cator consists of a stenciled cutout of the Interna-
tional Control and Display Symbol icon for “Fuel” in
the opaque layer of the instrument cluster overlay.
The dark outer layer of the overlay prevents the indi-
cator from being clearly visible when it is not illumi-
nated. 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 Emitting Diode (LED) soldered
onto the instrument cluster 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 Programmable Com-
munications Interface (PCI) data bus. The low fuel
indicator Light Emitting Diode (LED) receives bat-
tery current on the instrument cluster electronic cir-
cuit board through the fused ignition switch output
(run-start) 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 posi-
tion except On or Start. The LED only illuminates
when it is provided a path to ground by the instru-
ment cluster transistor. The instrument cluster will
turn on the low fuel indicator for the following rea-
sons:

• Bulb Test - Each time the ignition switch is

turned to the On position the indicator is illuminated
for about two seconds as a bulb test.

• Less 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.

• Less 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.

• More 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.

• Actuator Test - Each time the cluster is put

through the actuator test, the indicator will be
turned on, then off again during the bulb check por-
tion 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 PCI data bus, or the message
inputs to the instrument cluster that control the low
fuel indicator, a DRBIII

t scan 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 in the Information Center area of the instru-
ment cluster overlay, to the left of center. The MIL
consists of a stencilled cutout of the International
Control and Display Symbol icon for “Engine” in the
opaque layer of the instrument cluster overlay. The

INSTRUMENT CLUSTER

8J - 23

HIGH BEAM INDICATOR (Continued)

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 Emitting Diode (LED) soldered onto the instru-
ment cluster electronic circuit board. The MIL is ser-
viced 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 Programma-
ble Communications Interface (PCI) data bus. The
MIL Light Emitting Diode (LED) receives battery
current on the instrument cluster electronic circuit
board through the fused ignition switch output (run-
start) 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 MIL for the following reasons:

• Bulb Test - Each time the ignition switch is

turned to the On position the indicator is illuminated
for about seven seconds as a bulb test.

• PCM 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).

• Communication 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.

• Actuator 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 monitors 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 PCI data bus, or the message inputs to
the instrument cluster that control the MIL, a
DRBIII

t scan 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 odometer
and 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 odom-
eter VFD. When the trip odometer information is dis-
played, the word “TRIP” is also illuminated in a
green color and at the same lighting level as the trip
odometer information in the lower right corner of the
VFD. Both the odometer and the trip odometer infor-
mation is stored in the instrument cluster memory.

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

8J - 24

INSTRUMENT CLUSTER

MALFUNCTION INDICATOR LAMP (MIL) (Continued)

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 “Parade” 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 cluster programming
and electronic messages received by the cluster from
the Powertrain Control Module (PCM) over the Pro-
grammable Communications Interface (PCI) data
bus. The odometer and trip odometer information is
displayed by the instrument cluster Vacuum Fluores-
cent Display (VFD), and the VFD will not display
odometer or trip odometer information after the igni-
tion switch is turned to the Off position. The instru-
ment cluster circuitry controls the VFD and provides
the following features:

• Odometer/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-
played when the ignition switch was turned to the
Off position.

• Trip 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.

• Message 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.

• Actuator 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 PCI data bus, or
the message inputs to the instrument cluster that
control the odometer/trip odometer, a DRBIII

t scan

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 from “L” (or Low) to “H” (or High). An Interna-
tional Control and Display Symbol icon for “Engine
Oil” is located on the cluster overlay, in the center of
the gauge directly above the hub of the gauge needle.
The oil pressure gauge graphics are white against a
black field except for a single red graduation at the
low end of the gauge scale, making them clearly vis-
ible within the instrument cluster in daylight. When
illuminated 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

INSTRUMENT CLUSTER

8J - 25

ODOMETER (Continued)

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