1998 DODGE RAM 1500 Ignition switch

NOTE: Certain indicators in this instrument cluster
are automatically configured. This feature allows
those indicators to be activated or deactivated for
compatibility with certain optional equipment. If the
problem being diagnosed involves improper illumi-
nation of the cruise indicator, the electronic throttle
control indicator, the service four-wheel drive indi-
cator, the tow/haul indicator, the transmission over-
temp indicator, the upshift indicator, the security
indicator or the gear selector indicator, disconnect
and isolate the battery negative cable. After about
five minutes, reconnect the battery negative cable
and turn the ignition switch to the On position. The
instrument cluster should automatically relearn the
equipment in the vehicle and properly configure the
configurable indicators accordingly.
ABS INDICATOR
DESCRIPTION
An Antilock Brake System (ABS) indicator is stan-
dard equipment on all instrument clusters (Fig. 8).
However, the instrument cluster can be programmed
to disable this indicator on vehicles that are not
equipped with the ABS or Rear Wheel Anti-Lock
(RWAL) brake systems, which are not available in
some markets. On vehicles equipped with a gasoline
engine, the ABS indicator is located near the lower
edge of the instrument cluster, between the tachom-
eter and the speedometer. On vehicles equipped with
a diesel engine, the ABS indicator is located on the
right side of the instrument cluster, to the right of
the engine temperature gauge. The ABS indicator
consists of a stencil-like cutout of the International
Control and Display Symbol icon for ªFailure of Anti-
lock Braking Systemº in the opaque layer of the
instrument cluster overlay. The dark outer layer of
the overlay prevents the indicator from being clearly
visible when it is not illuminated. An amber Light
Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the icon to appear
in amber through the translucent outer layer of the
overlay when the indicator is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The ABS
indicator is serviced as a unit with the instrument
cluster.
OPERATION
The ABS indicator gives an indication to the vehi-
cle operator when the ABS system is faulty or inop-
erative. This indicator is controlled by a transistor on
the instrument cluster circuit board based upon clus-
ter programming and electronic messages received by
the cluster from the Controller Antilock Brake (CAB)
over the Programmable Communications Interface
(PCI) data bus. The ABS indicator Light Emitting
Diode (LED) is completely controlled by the instru-
ment cluster logic circuit, and that logic will only
allow this indicator to operate when the instrument
cluster receives a battery current input on the fused
ignition switch output (run-start) circuit. Therefore,
the LED will always be off when the ignition switch
is in any position except On or Start. The LED only
illuminates when it is provided a path to ground by
the instrument cluster transistor. The instrument
cluster will turn on the ABS indicator for the follow-
ing reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the ABS indicator is illu-
minated by the cluster for about two seconds as a
bulb test.
²ABS Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the CAB, the
ABS indicator will be illuminated. The indicator
remains illuminated until the cluster receives a
lamp-off message from the CAB, or until the ignition
switch is turned to the Off position, whichever occurs
first.
²Communication Error- If the cluster receives
no lamp-on or lamp-off messages from the CAB for
three consecutive seconds, the ABS indicator is illu-
minated. The indicator remains illuminated until the
cluster receives a valid message from the CAB, or
until the ignition switch is turned to the Off position,
whichever occurs first.
²Actuator Test- Each time the instrument clus-
ter is put through the actuator test, the ABS indica-
tor will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
²ABS Diagnostic Test- The ABS indicator is
blinked on and off by lamp-on and lamp-off messages
from the CAB during the performance of the ABS
diagnostic tests.
The CAB continually monitors the ABS circuits
and sensors to decide whether the system is in good
operating condition. The CAB then sends the proper
lamp-on or lamp-off messages to the instrument clus-
ter. If the CAB sends a lamp-on message after the
bulb test, it indicates that the CAB has detected a
system malfunction and/or that the ABS system has
become inoperative. The CAB will store a Diagnostic
Trouble Code (DTC) for any malfunction it detects.
Fig. 8 ABS Indicator
DRINSTRUMENT CLUSTER 8J - 17
INSTRUMENT CLUSTER (Continued)

Each time the ABS indicator fails to light due to an
open or short in the cluster ABS indicator circuit, the
cluster sends a message notifying the CAB of the
condition, then the instrument cluster and the CAB
will each store a DTC. For proper diagnosis of the
antilock brake system, the CAB, the PCI data bus, or
the electronic message inputs to the instrument clus-
ter that control the ABS indicator, a DRBIIItscan
tool is required. Refer to the appropriate diagnostic
information.
AIRBAG INDICATOR
DESCRIPTION
An airbag indicator is standard equipment on all
instrument clusters (Fig. 9). However, the instrument
cluster can be programmed to disable this indicator
on vehicles that are not equipped with the airbag
system, which is not available in some markets. The
airbag indicator is located near the upper edge of the
instrument cluster, between the tachometer and the
speedometer. The airbag indicator consists of a sten-
cil-like cutout of the words ªAIR BAGº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. A red
Light Emitting Diode (LED) behind the cutout in the
opaque layer of the overlay causes the ªAIR BAGº
text to appear in red through the translucent outer
layer of the overlay when the indicator is illuminated
from behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The air-
bag indicator is serviced as a unit with the instru-
ment cluster.
OPERATION
The airbag indicator gives an indication to the
vehicle operator when the airbag system is faulty or
inoperative. The airbag 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 Airbag Control
Module (ACM) over the Programmable Communica-
tions Interface (PCI) data bus. The airbag indicator
Light Emitting Diode (LED) is completely controlled
by the instrument cluster logic circuit, and that logic
will only allow this indicator to operate when the
instrument cluster receives a battery current input
on the fused ignition switch output (run-start) cir-
cuit. Therefore, the LED will always be off when theignition 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 airbag indicator
for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the airbag indicator is illu-
minated for about six seconds. The entire six second
bulb test is a function of the ACM.
²ACM Lamp-On Message- Each time the clus-
ter receives a lamp-on message from the ACM, the
airbag indicator will be illuminated. The indicator
remains illuminated for about twelve seconds or until
the cluster receives a lamp-off message from the
ACM, whichever is longer.
²Communication Error- If the cluster receives
no airbag messages for three consecutive seconds, the
airbag indicator is illuminated. The indicator
remains illuminated until the cluster receives a sin-
gle lamp-off message from the ACM.
²Actuator Test- Each time the cluster is put
through the actuator test, the airbag 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 actuator
test illumination of the airbag indicator is a function
of the instrument cluster.
The ACM continually monitors the airbag system
circuits and sensors to decide whether the system is
in good operating condition. The ACM then sends the
proper lamp-on or lamp-off messages to the instru-
ment cluster. If the ACM sends a lamp-on message
after the bulb test, it indicates that the ACM has
detected a system malfunction and/or that the air-
bags and seat belt tensioners may not deploy when
required, or may deploy when not required. The ACM
will store a Diagnostic Trouble Code (DTC) for any
malfunction it detects. Each time the airbag indicator
fails to illuminate due to an open or short in the
cluster airbag indicator circuit, the cluster sends a
message notifying the ACM of the condition, the
instrument cluster and the ACM will each store a
DTC, and the cluster will flash the seatbelt indicator
on and off as a backup to notify the vehicle operator.
For proper diagnosis of the airbag system, the ACM,
the PCI data bus, or the electronic message inputs to
the instrument cluster that control the airbag indica-
tor, a DRBIIItscan tool is required. Refer to the
appropriate diagnostic information.
Fig. 9 Airbag Indicator
8J - 18 INSTRUMENT CLUSTERDR
ABS INDICATOR (Continued)

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

DIAGNOSIS AND TESTING - BRAKE INDICATOR
The diagnosis found here addresses an inoperative
brake indicator condition. If there are problems with
several indicators in the instrument cluster, (Refer to
8 - ELECTRICAL/INSTRUMENT CLUSTER - DIAG-
NOSIS AND TESTING). If the brake indicator stays
on with the ignition switch in the On position and
the park brake released, or comes on while driving,
the brake system must be diagnosed and repaired
prior to performing the following tests. (Refer to 5 -
BRAKES - DIAGNOSIS AND TESTING). If no brake
system problem is found, the following procedures
will help to locate a shorted or open circuit, or a
faulty park brake switch input. Refer to the appropri-
ate 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 connec-
tors, splices and grounds.
WARNING: TO AVOID PERSONAL INJURY OR
DEATH, ON VEHICLES EQUIPPED WITH AIRBAGS,
DISABLE THE SUPPLEMENTAL RESTRAINT SYS-
TEM BEFORE ATTEMPTING ANY STEERING
WHEEL, STEERING COLUMN, AIRBAG, SEAT BELT
TENSIONER, IMPACT SENSOR, OR INSTRUMENT
PANEL COMPONENT DIAGNOSIS OR SERVICE.
DISCONNECT AND ISOLATE THE BATTERY NEGA-
TIVE (GROUND) CABLE, THEN WAIT TWO MINUTES
FOR THE SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE SUPPLEMENTAL RESTRAINT SYSTEM.
FAILURE TO TAKE THE PROPER PRECAUTIONS
COULD RESULT IN ACCIDENTAL AIRBAG DEPLOY-
MENT.
INDICATOR ILLUMINATES DURING BULB TEST, BUT DOES
NOT WHEN PARK BRAKE APPLIED
(1) Disconnect and isolate the battery negative
cable. Disconnect the body wire harness connector for
the park brake switch from the switch terminal.
Apply the parking brake. Check for continuity
between the park brake switch terminal and a good
ground. There should be continuity. If OK, go to Step
2. If not OK, replace the faulty park brake switch.
(2) Disconnect the instrument panel wire harness
connector (Connector C1) for the instrument cluster
from the cluster connector receptacle. Check for con-
tinuity between the park brake switch sense circuit
cavities of the body wire harness connector for the
park brake switch and the instrument panel wire
harness connector for the instrument cluster. There
should be continuity. If not OK, repair the open parkbrake switch sense circuit between the park brake
switch and the instrument cluster as required.
INDICATOR REMAINS ILLUMINATED - BRAKE SYSTEM
CHECKS OK
(1) Disconnect and isolate the battery negative
cable. Disconnect the body wire harness connector for
the park brake switch from the switch terminal.
Check for continuity between the terminal of the
park brake switch and a good ground. There should
be no continuity with the park brake released, and
continuity with the park brake applied. If OK, go to
Step 2. If not OK, replace the faulty park brake
switch.
(2) Disconnect the instrument panel wire harness
connector (Connector C1) for the instrument cluster
from the cluster connector receptacle. Check for con-
tinuity between the park brake switch sense circuit
cavity of the body wire harness connector for the
park brake switch and a good ground. There should
be no continuity. If not OK, repair the shorted park
brake switch sense circuit between the park brake
switch and the instrument cluster as required.
CARGO LAMP INDICATOR
DESCRIPTION
A cargo lamp indicator is standard equipment on
all instrument clusters (Fig. 11). The cargo lamp
indicator is located on the right side of the instru-
ment cluster, to the right of the oil pressure gauge.
The cargo lamp indicator consists of a stencil-like
cutout of the words ªCARGO LAMPº in the opaque
layer of the instrument cluster overlay. The dark
outer layer of the overlay prevents the indicator from
being clearly visible when it is not illuminated. An
amber Light Emitting Diode (LED) behind the cutout
in the opaque layer of the overlay causes the
ªCARGO LAMPº text to appear in amber through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by the LED, which
is soldered onto the instrument cluster electronic cir-
cuit board. The cargo lamp indicator is serviced as a
unit with the instrument cluster.
OPERATION
The cargo lamp indicator gives an indication to the
vehicle operator when the exterior cargo lamp is illu-
minated. This indicator is controlled by a transistor
on the instrument cluster circuit board based upon
Fig. 11 Cargo Lamp Indicator
8J - 20 INSTRUMENT CLUSTERDR
BRAKE/PARK BRAKE INDICATOR (Continued)

cluster programming, a hard wired multiplex input
received by the cluster from the headlamp panel
lamps dimmer switch on the headlamp dimmer
switch mux circuit, and electronic unlock request
messages received from the optional Remote Keyless
Entry (RKE) receiver module. The cargo lamp indica-
tor Light Emitting Diode (LED) is completely con-
trolled by the instrument cluster logic circuit, and
that logic will allow only this indicator to operate
whenever the instrument cluster receives a battery
current input on the fused ignition switch output
(run-start) circuit. Therefore, the LED will always be
off when the ignition switch is in any position except
On or Start. The LED only illuminates when it is
provided a path to ground by the instrument cluster
transistor. The instrument cluster will turn on the
cargo lamp indicator for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the cargo lamp indicator is
illuminated for about two seconds as a bulb test.
²Cargo Lamp-On Input- Each time the cluster
detects a cargo lamp-on input from the headlamp
switch on the headlamp dimmer switch mux circuit,
the cargo lamp and the cargo lamp indicator will be
illuminated. The cargo lamp and indicator remain
illuminated until the cluster receives a cargo lamp-off
input from the headlamp switch, 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 cargo lamp indicator
will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
The instrument cluster continually monitors the
headlamp dimmer switch circuit to determine the
proper interior lamps features and panel lamps illu-
mination levels to provide. The cluster then energizes
and de-energizes a low side driver circuit to control
the exterior cargo lamp. Each time the instrument
cluster energizes the cargo lamp driver and the igni-
tion switch is in the On or start positions, the cluster
also turns on the cargo lamp indicator. For further
diagnosis of the cargo lamp indicator or the instru-
ment cluster circuitry that controls the indicator,
(Refer to 8 - ELECTRICAL/INSTRUMENT CLUS-
TER - DIAGNOSIS AND TESTING). For proper
diagnosis of the cargo lamp or the headlamp switch
inputs to the instrument cluster that control the
cargo lamp indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.CHECK GAUGES INDICATOR
DESCRIPTION
A check gauges indicator is standard equipment on
all instrument clusters (Fig. 12). On vehicles
equipped with a gasoline engine, the check gauges
indicator is located near the lower edge of the instru-
ment cluster, between the tachometer and the speed-
ometer. On vehicles equipped with a diesel engine,
the check gauges indicator is located on the left side
of the instrument cluster, to the left of the voltage
gauge. The check gauges indicator consists of a sten-
cil-like cutout of the words ªCHECK GAGESº in the
opaque layer of the instrument cluster overlay. The
dark outer layer of the overlay prevents the indicator
from being clearly visible when it is not illuminated.
A red Light Emitting Diode (LED) behind the cutout
in the opaque layer of the overlay causes the
ªCHECK GAGESº text to appear in red through the
translucent outer layer of the overlay when the indi-
cator is illuminated from behind by the LED, which
is soldered onto the instrument cluster electronic cir-
cuit board. The check gauges indicator is serviced as
a unit with the instrument cluster.
OPERATION
The check gauges indicator gives an indication to
the vehicle operator when certain instrument cluster
gauge readings reflect a condition requiring immedi-
ate attention. This indicator is controlled by a tran-
sistor on the instrument cluster circuit board based
upon cluster programming and electronic messages
received by the cluster from the Powertrain Control
Module (PCM) on vehicles equipped with a gasoline
engine, or from the Engine Control Module (ECM) on
vehicles equipped with a diesel engine over the Pro-
grammable Communications Interface (PCI) data
bus. The check gauges indicator Light Emitting
Diode (LED) is completely controlled by the instru-
ment cluster logic circuit, and that logic will only
allow this indicator to operate when the instrument
cluster receives a battery current input on the fused
ignition switch output (run-start) circuit. Therefore,
the LED will always be off when the ignition switch
is in any position except On or Start. The LED only
illuminates when it is provided a path to ground by
the instrument cluster transistor. The instrument
cluster will turn on the check gauges indicator for
the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the check gauges indicator
is illuminated for about two seconds as a bulb test.
Fig. 12 Check Gauges Indicator
DRINSTRUMENT CLUSTER 8J - 21
CARGO LAMP INDICATOR (Continued)

²Engine Temperature High Message- Each
time the cluster receives a message from the PCM or
ECM indicating the engine coolant temperature of a
gasoline engine is about 122É C (252É F) or higher, or
of a diesel engine is about 112É C (233É F) or higher,
the check gauges indicator will be illuminated. The
indicator remains illuminated until the cluster
receives a message from the PCM or ECM indicating
that the engine coolant temperature of a gasoline
engine is below about 122É C (252É F), or of a diesel
engine is below about 112É C (233É F), or until the
ignition switch is turned to the Off position, which-
ever occurs first.
²Engine Oil Pressure Low Message- Each
time the cluster receives a message from the PCM or
ECM indicating the engine oil pressure is about 41
kPa (6 psi) or lower, the check gauges indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a message from the PCM or
ECM indicating that the engine oil pressure is above
about 41 kPa (6 psi), or until the ignition switch is
turned to the Off position, whichever occurs first.
The cluster will only turn the indicator on in
response to an engine oil pressure low message if the
engine speed is greater than zero.
²System Voltage Low (Charge Fail) Message
- Each time the cluster receives a message from the
PCM or ECM indicating the electrical system voltage
is less than about 11.5 volts (charge fail condition),
the check gauges indicator will be illuminated. The
indicator remains illuminated until the cluster
receives a message from the PCM or ECM indicating
the electrical system voltage is greater than about
12.0 volts (but less than 16.0 volts), or until the igni-
tion switch is turned to the Off position, whichever
occurs first.
²System Voltage High Message- Each time
the cluster receives a message from the PCM or ECM
indicating the electrical system voltage is greater
than about 16.0 volts, the check gauges indicator will
be illuminated. The indicator remains illuminated
until the cluster receives a message from the PCM or
ECM indicating the electrical system voltage is less
than about 15.5 volts (but greater than 11.5 volts), 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 check gauges indicator
will be turned on, then off again during the bulb
check portion of the test to confirm the functionality
of the LED and the cluster control circuitry.
On vehicles with a gasoline engine, the PCM con-
tinually monitors the engine temperature, oil pres-
sure, and electrical system voltage, then sends the
proper messages to the instrument cluster. On vehi-
cles with a diesel engine, the ECM continually mon-itors the engine temperature, oil pressure, and
electrical system voltage, then sends the proper mes-
sages to the instrument cluster. For further diagnosis
of the check gauges indicator or the instrument clus-
ter circuitry that controls the LED, (Refer to 8 -
ELECTRICAL/INSTRUMENT CLUSTER - DIAGNO-
SIS AND TESTING). For proper diagnosis of the
PCM, the ECM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the check gauges indicator, a DRBIIItscan tool is
required. Refer to the appropriate diagnostic infor-
mation.
CRUISE INDICATOR
DESCRIPTION
A cruise indicator is standard equipment on all
instrument clusters (Fig. 13). However, on vehicles
not equipped with the optional speed control system,
this indicator is electronically disabled. The cruise
indicator consists of the word ªCRUISEº, which
appears in the lower portion of the gear selector indi-
cator Vacuum-Fluorescent Display (VFD) unit. The
VFD is soldered onto the cluster electronic circuit
board and is visible through a window with a smoked
clear lens located on the lower edge of the speedom-
eter gauge dial face of the cluster overlay. The dark
lens over the VFD prevents the indicator from being
clearly visible when it is not illuminated. The word
ªCRUISEº appears in a blue-green color and at the
same lighting level as the gear selector indicator
information when it is illuminated by the instrument
cluster electronic circuit board. The cruise indicator
is serviced as a unit with the VFD in the instrument
cluster.
OPERATION
The cruise indicator gives an indication to the vehi-
cle operator when the speed control system is turned
On, regardless of whether the speed control is
engaged. This indicator is controlled by the instru-
ment cluster circuit board based upon cluster pro-
gramming and electronic messages received by the
cluster from the Powertrain Control Module (PCM)
over the Programmable Communications Interface
(PCI) data bus. The cruise indicator is completely
controlled by the instrument cluster logic circuit, and
that logic will only allow this indicator to operate
when the instrument cluster receives a battery cur-
rent input on the fused ignition switch output (run-
start) circuit. Therefore, the indicator will always be
Fig. 13 Cruise Indicator
8J - 22 INSTRUMENT CLUSTERDR
CHECK GAUGES INDICATOR (Continued)

off when the ignition switch is in any position except
On or Start. The indicator only illuminates when it is
switched to ground by the instrument cluster cir-
cuitry. The instrument cluster will turn on the cruise
indicator for the following reasons:
²Cruise Lamp-On Message- Each time the
cluster receives a cruise lamp-on message from the
PCM indicating the speed control system has been
turned On, the cruise indicator is illuminated. The
indicator remains illuminated until the cluster
receives a cruise 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 cruise indicator will be
turned on, then off again during the VFD portion of
the test to confirm the functionality of the VFD and
the cluster control circuitry.
The PCM continually monitors the speed control
switches to determine the proper outputs to the
speed control servo. The PCM then sends the proper
cruise indicator lamp-on and lamp-off messages to
the instrument cluster. For further diagnosis of the
cruise indicator or the instrument cluster circuitry
that controls the indicator, (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). For proper diagnosis of the speed control
system, the PCM, the PCI data bus, or the electronic
message inputs to the instrument cluster that control
the cruise indicator, a DRBIIItscan tool is required.
Refer to the appropriate diagnostic information.
DOOR AJAR INDICATOR
DESCRIPTION
A door ajar indicator is standard equipment on all
instrument clusters (Fig. 14). The door ajar indicator
is located on the right side of the instrument cluster,
to the right of the engine temperature gauge. The
door ajar indicator consists of a stencil-like cutout of
the words ªDOOR AJARº in the opaque layer of the
instrument cluster overlay. The dark outer layer of
the overlay prevents the indicator from being clearly
visible when it is not illuminated. A red Light Emit-
ting Diode (LED) behind the cutout in the opaque
layer of the overlay causes the ªDOOR AJARº text to
appear in red through the translucent outer layer of
the overlay when the indicator is illuminated from
behind by the LED, which is soldered onto the
instrument cluster electronic circuit board. The doorajar indicator is serviced as a unit with the instru-
ment cluster.
OPERATION
The door ajar indicator gives an indication to the
vehicle operator that one or more of the passenger
compartment doors may be open or not completely
latched. This indicator is controlled by a transistor
on the instrument cluster circuit board based upon
cluster programming and hard wired inputs received
by the cluster from the door ajar switches located in
each door latch unit. The door ajar indicator Light
Emitting Diode (LED) is completely controlled by the
instrument cluster logic circuit, and that logic will
allow this indicator to operate whenever the instru-
ment cluster receives a battery current input on the
fused ignition switch output (run-start) circuit.
Therefore, the LED will always be off when the igni-
tion 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 door ajar indica-
tor for the following reasons:
²Bulb Test- Each time the ignition switch is
turned to the On position the door ajar indicator is
illuminated for about two seconds as a bulb test.
²Door Ajar Switch Input- Each time the clus-
ter detects ground on any one of the door ajar switch
sense circuits (door ajar switch closed = door is open
or not completely latched) the door ajar indicator will
be illuminated. The indicator remains illuminated
until all of the door ajar switch sense inputs to the
cluster are an open circuit (door ajar switch open =
door fully closed), 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 door ajar indicator will
be turned on, then off again during the bulb check
portion of the test to confirm the functionality of the
LED and the cluster control circuitry.
The instrument cluster continually monitors the
door ajar switches to determine the status of the
doors. For further diagnosis of the door ajar indicator
or the instrument cluster circuitry that controls the
indicator, (Refer to 8 - ELECTRICAL/INSTRUMENT
CLUSTER - DIAGNOSIS AND TESTING). For
proper diagnosis of the door ajar switches and cir-
cuits, (Refer to 8 - ELECTRICAL/LAMPS/LIGHTING
- INTERIOR/DOOR AJAR SWITCH - DIAGNOSIS
AND TESTING).
Fig. 14 Door Ajar Indicator
DRINSTRUMENT CLUSTER 8J - 23
CRUISE INDICATOR (Continued)

ENGINE TEMPERATURE
GAUGE
DESCRIPTION
An engine coolant temperature gauge is standard
equipment on all instrument clusters. The engine
coolant temperature gauge is located in the lower
right quadrant of the instrument cluster, below the
oil pressure gauge. The engine coolant temperature
gauge consists 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 ªCº (or Cold) to ªHº (or Hot)
for gasoline engines. On vehicles with a diesel
engine, the scale reads from ª60ºÉ C to ª120ºÉ C in
markets where a metric instrument cluster is speci-
fied, or from ª140ºÉ F to ª245ºÉ F in all other mar-
kets. An International Control and Display Symbol
icon for ªEngine Coolant Temperatureº is located on
the cluster overlay, directly below the left end of the
gauge scale (Fig. 15). The engine coolant temperature
gauge graphics are black against a white field except
for two red graduations at the high end of the gauge
scale, making them clearly visible within the instru-
ment cluster in daylight. When illuminated from
behind by the panel lamps dimmer controlled cluster
illumination lighting with the exterior lamps turned
On, the black graphics appear blue and the red
graphics still appear red. The orange gauge needle is
internally illuminated. Gauge illumination is pro-
vided by replaceable incandescent bulb and bulb
holder units located on the instrument cluster elec-
tronic circuit board. The engine coolant temperature
gauge is serviced as a unit with the instrument clus-
ter.
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 cluster
programming and electronic messages received by
the cluster from the Powertrain Control Module
(PCM) on vehicles equipped with a gasoline engine,
or from the Engine Control Module (ECM) on vehi-
cles equipped with a diesel engine over the Program-
mable Communications Interface (PCI) data bus. The
engine coolant temperature gauge 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 (run-start) circuit when-ever the ignition switch is in the On or Start posi-
tions. The cluster is programmed to move the gauge
needle back to the low end of the scale after the igni-
tion switch is turned to the Off position. The instru-
ment 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 or ECM
indicating the engine coolant temperature is between
the low end of normal [about 54É C (130É F) for gas-
oline engines, or about 60É C (140É F) for diesel
engines] and the high end of normal [about 122É C
(252É F) for gasoline engines, or about 116É C (240É
F) for diesel engines], the gauge needle is moved to
the actual relative temperature position on the gauge
scale.
²Engine Temperature Low Message- Each
time the cluster receives a message from the PCM or
ECM indicating the engine coolant temperature is
below the low end of normal [about 54É C (130É F) for
gasoline engines, or about 60É C (140É F) for diesel
engines], the gauge needle is held at the graduation
on the far left end of the gauge scale. The gauge nee-
dle remains at the left end of the gauge scale until
the cluster receives a message from the PCM or ECM
indicating that the engine temperature is above
about 54É C (130É F) for gasoline engines, or about
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 or
ECM indicating the engine coolant temperature is
above about 122É C (252É F) for gasoline engines, or
about 116É C (240É F) for diesel engines, the gauge
needle is moved into the red zone at the far right end
of gauge scale, the check gauges indicator is illumi-
nated, and a single chime tone is sounded. The gauge
needle remains in the red zone and the check gauges
indicator remains illuminated until the cluster
receives a message from the PCM or ECM indicating
that the engine temperature is below about 122É C
(252É F) for gasoline engines, or about 116É C (240É
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 messages from the PCM or ECM.
²Communication Error- If the cluster fails to
receive an engine temperature message, it will hold
the gauge needle at the last indication for about five
seconds or until the ignition switch is turned to the
Off position, whichever occurs first. After five sec-
onds, the cluster will move the gauge needle to the
low end of the gauge scale.
Fig. 15 Engine Coolant Temperature Icon
8J - 24 INSTRUMENT CLUSTERDR