1993 DODGE TRUCK sensor
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IGNITION
SYSTEMS
8D - 29
ENGINE FIRING ORDER—5.2L/5.9L V-8 EN
GINES TORQUE
FRONT
OF
ENGINE
CLOCKWISE
ROTATION
1-8-4-3-6-5-7-2
Description
Torque
Crankshaft
Position
Sensor..
Distributor Hold Down Bolt..
Powertrain
Control Module
Mounting
Screws............
Powertrain
Control Module
(PCM)
Elect. Connector...
Spark
Plugs
All Engines
8
N*m (70
in.
lbs.)
23
N«m(17ft.ibs.)
1
N«m (9 in. lbs.)
4 N*m (35
in.
lbs.)
41
N<>m
(30
ft.
lbs.)
J9314-166
J9314-79
1
Page 382 of 1502
• • ^ ^ ^ INSTRUMENT PANEL AND GAUGES 8E - 1
CONTENTS
page
CLUSTER AND GAUGE SERVICE PROCEDURES . 12
CLUSTER AND GAUGE TEST PROCEDURES .. i
GENERAL INFORMATION . 1
page
MESSAGE CENTER-DIESEL ENGINE ........ 4
MESSAGE CENTER-GAS ENGINE .......... 3
SWITCH
AND PANEL COMPONENT SERVICE . 16
GENERAL
INFORMATION
INDEX
page
Generator
Indicating
System
2
Distance
Sensor
2
Electronic
Digital
Clock
3
Fuel
Level
Indicating
System
1
page
Malfunction
Indicator
(Check
Engine)
3
Oil
Pressure
Warning
Lamp
................. 2
Speedometer/Odometer
System
2
Temperature
and Oil
Indicating
System
......... 2
D-body trucks have an instrument cluster which
includes gauges for fuel level, coolant temperature,
oil pressure, and charging system voltage (Fig. 1).
When the ignition switch is in the OFF position all
the gauges will show a reading except the voltage gauge. However, the readings are only accurate
when the ignition switch is in the ON position.
The cluster also includes warning lamps for:
• seat belt warning
• low oil pressure
• high beam
• left and right turn signals
• check engine. J908E-66
Fig.
11nstrument
Cluster
FUEL LEVEL INDICATING SYSTEM (FIG. 2)
A hinged float arm in the fuel tank raises or lowers
depending on the fuel level. The float arm contacts a
variable resistor in the gauge sending unit. This pro
vides a change of resistance in the fuel gauge circuit
with any up or down movement of the float. This sender
resistance is shown as fuel level on the gauge. Resistance is greatest when the fuel level in the
tank is low and the float arm drops. With high resis
tance current flow is low and consequently positions
the instrument panel gauge pointer to low.
Resistance in the circuit is at a minimum when the
tank is full and the float arm is raised. With resis
tance at a minimum, current flow is high registering
full on the instrument panel gauge.
12
VOLTS
TO
GAUGE
IP
FUEL
TANK
SENDING
UNIT
FLOAT
SENDING
UNIT
1:
1
j
^
fCONNECTOR
!g|yj-»—
FUEL
GAUGE
FUEL
TANK
J098E-47
Fig.
2
Fuel
Level
Indicating
System
INSTRUMENT PANEL AND GAUGES
Page 383 of 1502
8E
- 2
INSTRUMENT PANEL
AND
GAUGES
•
TEMPERATURE AND
OIL
INDICATING SYSTEM
(FIG.
3) The operation of the temperature and oil pressure
indicating systems are identical. In the temperature
system the sending unit resistance varies in direct
relationship to the temperature of the coolant. When the engine is cold, the resistance of the tem
perature sending unit is high and a cold temperature
will be indicated on the gauge. When the engine is hot, the resistance of the tem
perature sending unit is low and a hot temperature
will be indicated on the gauge. In the oil pressure indicating system the sending
unit resistance is actuated by a diaphragm as the oil
pressure increases or decreases. Low oil pressure causes high resistance. High pressure causes low re
sistance. 12
VOLTS
TO
GAUGE
TEMPERATURE/
OIL GAUGE
TEMPERATURE/OIL SENDING
UNIT
J908E-48
Fig. 3 Temperature/Oil indicating System
OIL
PRESSURE
WARNING LAMP
The oil pressure warning switch, mounted on the
engine, is controlled by engine oil pressure. When engine oil pressure is normal, the switch is
held in the OFF or OPEN position. This stops cur
rent from flowing to the oil pressure warning lamp
on instrument panel. When the engine oil pressure is low, the switch is
in the ON or CLOSED position. This allows current
to flow to the oil pressure warning lamp in the in strument cluster causing the warning lamp to illumi
nate.
GENERATOR
INDICATING
SYSTEM
(FIG. 4)
The voltmeter gauge senses the voltage of the elec
trical system.
VOLTAGE
/*
GAUGE
P/
J908E-49 Fig. 4 Generator Indicating System
SPEEDOMETER/ODOMETER SYSTEM
The speedometer/odometer system consists of an
electric speedometer and pushbutton reset odometer
mounted in the cluster. The system also includes the
wire harness from the cluster to the distance sensor at the transmission, and the adapter and pinion in
the transmission. The speedometer/odometer has the same appearance as a conventional version but it
eliminates the cable-driven mechanical system. A signal is sent from a transmission mounted distance
sensor to the speedometer/odometer circuitry through
the wiring harness. By eliminating the speedometer cable, instrument cluster service and removal is im
proved. Refer to Group 21 - Transmission for select ing the proper pinion, and selecting and indexing the
proper adapter.
DISTANCE
SENSOR
DISTANCE SENSOR TEST For testing of the distance sensor and related com
ponents refer to the Vehicle Diagnostics Test Proce dure Manual.
DISTANCE SENSOR REMOVAL AND INSTALLATION (1) Remove harness connector from sensor. Be sure
weather seal stays on harness connector. (2) Remove sensor by loosening sensor coupling
nut from the pinion gear adapter until sensor is free (Fig. 5).
(3) To install the sensor, reverse the removal pro
cedures. Tighten coupling nut to 17 N»m (150 in. lbs.)
Page 384 of 1502
•
INSTRUMENT PANEL
AND
GAUGES
8E - 3
MALFUNCTION INDICATOR (CHECK ENGINE)
Fig.
5
Distance Sensor
If
the
input from
one of the
following sensors fails
an internal Powertrain Control Module
(PCM)
self
check,
the PCM
turns
on the
Check Engine Lamp. The
PCM
then substitutes
a
modified signal
in
place
of
the one
that failed until
a
repair
is
made:
• Manifold Absolute Pressure (MAP) Sensor
• Throttle Position Sensor
• Coolant Temperature Sensor
• Battery Voltage Sense
• Battery Voltage
Too
High
Refer
to the
appropriate Powertrain Diagnostic
Test Procedures manual
for
further information.
ELECTRONIC DIGITAL CLOCK
The electronic digital clock
is in the
radio.
The
clock
and
radio each
use the
display panel built into
the radio.
A
digital readout indicates
the
time
in
hours
and
minutes whenever
the
ignition switch
is in
the
ON or ACC
position. When
the
ignition switch
is in the OFF
position
or
when
the
radio frequency
is
being displayed, time keeping
is
accurately maintained. The procedure
for
setting
the
clock varies slightly
with each radio.
The
correct procedure
is
described under
the
individual radio operating instructions
re
ferred
to in the
Owner Manual supplied with
the ve
hicle.
MESSAGE CENTER—GAS ENGINE
The message center
(Fig. 6),
located above
the
Heater-A/C controls, includes warning lamps
for the:
• brake systems (parking
and
service)
•
ABS
brakes • liftgate open (Ramcharger only)
• maintenance required.
O/D
BRAKE
(P)(7
GATE OPEN
MAINT
REQD.
J938E-54
Fig.
6
Message Center—Gas Engine
EMISSIONS
MAINTENANCE REMINDER
This system
is
designed
to act as a
reminder that
scheduled vehicle emissions maintenance should
be
performed.
It is not
intended
to
indicate
a
warn
ing
or
that
a
state
of
emergency exists which must
be
corrected
to
insure safe vehicle opera
tion.
The
components covered
by the
system include
the
EGR
system,
PCV
valve,
and
oxygen sensor. Refer
to
Group
25 -
Emissions,
for
further informa
tion.
ABS
WARNING
LIGHT
This light monitors
the ABS
Brake System. This
light will come
on
when
the
ignition
key is
turned
to
the
ON
position
and may
stay
on for as
long
as
thirty seconds.
If the ABS
light remains
on or
comes on during driving,
it
indicates that
the ABS
portion
of
the
brake system
is not
functioning. Refer
to
Group
5 -
Brakes
for
further information.
BRAKE
SYSTEM WARNING
LIGHT
The dual brake system provides
a
reserve braking
capability
in the
event
of a
failure
to a
portion
of the
hydraulic system. Failure
of
either
of the
dual sys
tem
is
indicated
by the
brake warning light which
will glow when
the
service brake pedal
is
depressed.
The light will remain
on
until
the
cause
is
corrected. The light will also come
on
when
the
parking
brake
is
applied with
the
ignition
in the ON
position.
Refer
to
Group
5 -
Brakes
for
further information.
Page 385 of 1502
8E
- 4
INSTRUMENT PANEL
AND
GAUGES
•
MESSAGE CENTER—DIESEL
ENGINE
The message center (Fig. 7), which
is
located above
the Heater-A/C controls, includes warning lamps
for
the:
• brake systems (parking
and
service brakes)
• ABS brakes
• water
in
fuel
• wait
to
start (controlled
by Air
Heater Control
Module)
• Low Fuel.
BRAKE
CUMMINS
TURBO
DIESEL,
LOW
FUEL
DIESEL
FUEL ONLY WATER
IN
FUEL
WAIT
TO
START
J938E-55
Fig.
7
Message Center—Diesel Engine
ABS
WARNING LIGHT
This light monitors
the
ABS Brake System. This
light will come
on
when the ignition key
is
turned
to
the
ON
position
and may
stay
on for as
long
as
thirty seconds.
If
the ABS light remains
on or
comes
on during driving,
it
indicates that
the
ABS portion
of
the
brake system
is not
functioning. Refer
to
Group
5 -
Brakes
for
further information.
BRAKE
SYSTEM WARNING LIGHT
The Brake light
is
connected
to a
sensor that mon
itors vacuum
in
the brake booster system. The Brake
light when
lit
indicates LOW VACUUM. The dual brake system provides
a
reserve braking
capability
in
the event
of a
failure
to a
portion
of
the
hydraulic system. Failure
of
either
of the
dual sys
tem
is
indicated
by the
brake warning light which
will glow when
the
service brake pedal
is
depressed.
The light will remain
on
until
the
cause
is
corrected. The light will also come
on
when
the
parking
brake
is
applied with the ignition
in
the ON position. Refer
to
Group
5 -
Brakes
for
further information.
WATER
IN
FUEL
The Water
In
Fuel light
is
connected
to a
sensor lo
cated
in the
fuel filter.
If
water collects
in the
fuel/
water separator filter,
the
Water
In
Fuel indicator
will light.
WAIT
TO
START
The Wait
To
Start light
is
connected
to a
sensor
that monitors intake
air
temperature
in the
intake
manifold.
If
intake
air
temperature
is low and
igni
tion switch
is in
ON position,
the
PCM sends current
to
the
intake manifold
air
heaters
and the
Wait
To
Start light. This intake manifold preheat cycle
is
controlled
by an
electronic
Air
Heater Control Mod
ule.
LOW FUEL
The Low Fuel light
is
connected
to a
sensor
in the
fuel tank. When the fuel level reaches approximately 1/6
of a
tank,
the
words LOW FUEL will illuminate
and remain
on
until fuel
is
added.
Page 386 of 1502
•
INSTRUMENT PANEL
AND
GAUGES
8E - 5
CLUSTER
AND
GAUGE TEST
PROCEDURES
INDEX
page
Fuel Gauge
Circuit
Test
9
Fuel Tank Sending
Unit
Test
5
Oil Pressure Gauge
Circuit
Test
..............
9
Sending
Unit
(Sensor) Test
5
page
Speedometer
10
Temperature
Gauge
Circuit
Test
8
Voltage Gauge
Circuit
Test
10
Warning Lamp System Tests
6
CAUTION:
Disconnect
battery
negative cable,
in
en
gine compartment, before servicing instrument panel. When power
is
required
for
test purposes,
connect
battery
cable
(for
test only).
Disconnect battery negative cable after test
and before continuing service procedures.
SENDING
UNIT
(SENSOR) TEST
When
a
problem occurs with
a
cluster gauge,
be
fore disassembling
the
cluster
to
check
the
gauge, check
for a
defective sending unit (sensor)
or
wiring.
(1) Sending units
and
wiring
can be
checked
by
grounding
the
connector leads,
at the
sending unit,
in
the
vehicle.
CAUTION:
When connecting
an
input
terminal
to
ground,
Do Not
leave
the
connection grounded
for
more than
a
few
seconds.
(2) With
the
ignition
in the ON
position;
a
grounded input will cause
the oil,
fuel
or
tempera
ture gauge
to
read
at or
above maximum.
FUEL TANK SENDING
UNIT
TEST
(1) Disconnect wire from terminal
on
fuel tank
sending unit (Fig.
1).
FUEL PUMP SUPPLY
INPUT
TO
GAUGE
SENDING
UNIT
GROUND
FUEL PUMP GROUND
J928E-49
Fig.
1
Fuel
Tank
Sending
Connector
Terminals
(2) Connect wire
to a
known good sending unit.
(3) Connect
a
jumper wire between sending unit
fuel pick
up
tube
and a
good ground.
(4) Check fuel gauge
as
described
in
following
steps.
Allow
at
least three minutes
at
each test point
for gauge
to
settle. Lightly tapping instrument clus
ter
may
help position pointer.
FUEL GAUGE SYSTEM DIAGNOSIS
FUEL GAUGE SYSTEM DIAGNOSIS FUEL GAUGE
DOES
NOT
READ
FULL FAULTY PRINTED
CIRCUIT BOARD FUEL GAUGE
INOPERATIVE OR ERRATIC FUEL GAUGE
INACCURATE
E
1
I
CHECK
FAULTY WIRING
OR
TANK DEFORMED
TANK
NOT
FULL COMPONENTS
CHECK
CHECK
ALL WIRING INCLUDING GROUND
i
FAULTY FUEL GAUGE SENDING
UNIT
i 1
FUEL
C
1
DOES
1
READ
1
pAUGE
I
>N0?
1
EMPTY
1
r
TANK
NOT
EMPTY
CHECK
PROPER
ALIGNMENT
OF PICKUP AND
SENDER
ASSEMBLY.
REFER
TO
GROUP
14
FAULTY FUEL
GAUGE
J908E-74
Page 389 of 1502
8E
- 8 INSTRUMENT PANEL AND GAUGES
•
BRAKE
WARNING
LAMP
SWITCH TO BRAKE
WARNING LAMP
PR!
451
Fig.
6
Brake Warning
Lamp
Switch
depresses
the
brake pedal
and
observes
the
warning
lamp.
If
the
lamp fails
to
light, inspect
for:
•
a
burned
out
bulb
• disconnected socket
•
a
broken
or
disconnected wire
at the
switch. If
the
bulb
is not
burned
out and the
wire continu
ity
is
proven, replace
the
brake warning switch.
The
switch
is in the
brake line
Tee
fitting mounted
on
the frame rail
in the
engine compartment below
the
master cylinder.
CAUTION:
If
wheel cylinder bleeder
was
opened
check
master cylinder fluid level.
On Diesel Models
The
Brake light
is
also con
nected
to a
sensor that monitors vacuum
in the
brake booster system.
The
Brake light when
lit
indi cates
LOW
VACUUM. Refer
to
Group
5 -
Brakes
for
more information.
TEMPERATURE
GAUGE CIRCUIT TEST
(1) Remove temperature gauge. Refer
to
Gauge
Re
placement. (2) Check continuity
in the
wire between
the
tem
perature sensor
and the
temperature gauge (sensor
input
pin)
(Figs.
7, 8 and 9).
(3) With
the
ignition switch
in the ON
position,
check
for
battery voltage across
the B + pin and the
Ground
pin.
(TURN
IGNITION
KEY
"ON"
(DO
NOT
START
ENGINE
I
RELEASE
PARKING
BRAKE)
I
I
[
WARNING
LIGHT
GOES
I
"ON"
I
1
(LIGHT
SHOULD
BE
"OFF")!
X
APPLY PARKING BRAKE (WARNING
LIGHT
SHOULD
GO "ON")
BRAKE
SYSTEM
LEAKING FLUID
X
WARNING
LIGHT
FAILS
TO GO "ON" GROUNDED WIRING
BULB
BURNED
OUT
SHORTED PARKING BRAKE
OR BRAKE WARNING SWITCH
X
DISCONNECTED
OR
FAULTY
BULB
SOCKET
FAULTY BRAKE SYSTEM PROPORTIONING VALVE
UNIT*
BROKEN
WIRE
OR
WIRE
DISCONNECTED
AT
PARKING
BRAKE
SWITCH
X
FAULTY PARKING
BRAKE
SWITCH
X
APPLY SERVICE BRAKES
(WARNING
LIGHT
SHOULD
NOT GO "ON")
JZ
X
TEST SERVICE BRAKE WARNING
SYSTEM FUNCTION*
X
WARNING
LIGHT
GOES
"ON"
WARNING
LIGHT
DOES
NOT GO "ON"
BRAKE
SYSTEM
LEAKING FLUID
OPEN CIRCUIT
IN
WIRING
TO SERVICE BRAKE SWITCH
X
GROUNDED WIRING
OR
SHORTED BRAKE WARNING SWITCH
LOOSE
BULKHEAD CONNECTOR
X
FAULTY BRAKE SYSTEM
PROPORTIONING VALVE
UNIT*
FAULTY SERVICE BRAKE SWITCH
X
•TESTS
ARE
DESCRIBED
IN APPROPRIATE
SECTION
OF
SERVICE MANUAL
FAULTY SERVICE BRAKE
SYSTEM PROPORTIONING VALVE
UNIT*
PR1449A
Page 390 of 1502
INSTRUMENT
PANEL
AND
GAUGES
8E - S
J938E-34
Fig. 7 Coolant Temperature Sensor—Gas Engine
AIR
TEMPERATURE SWITCH
-
COOLANT TEMPERATURE
SWITCH
Fig. 8 Coolant Temperature Sensor—Diesel Engine
OIL PRESSURE
GAUGE
CIRCUIT
TEST
(1) Remove oil pressure gauge. Refer to Gauge Re
placement. (2) Check for continuity in the wire between the
oil pressure sensor and the oil pressure gauge (sensor
input pin) (Figs. 10, 11, 12 and 13). (3) With the ignition switch in the ON position,
check for battery voltage across the B+ pin and the Ground pin. J908E-6i_
Fig. 9 Temperature Gauge Pins
TEMPERATURE/OIL/FUEL
GAUGE
DIAGNOSIS
GAUGE INDICATES HIGHER
OR
LOWER
THAN
ACTUAL I
FAULTY WIRING
FAULTY SENDING
UNIT*
FAULTY INSTRUMENT PANEL
GAUGE*
ERRATIC
GAUGE OPERATION
'TEST
PROCEDURES
DESCRIBED
ARE
IN
APPROPRIATE
SECTION OF
SERVICE
MANUAL
LOOSE
OR DIRTY ELECTRICAL CONNECTIONS FAULTY INSTRUMENT PANEL
GAUGE*
J908E-52
FUEL
GAUGE
CIRCUIT
TEST
(1) Remove fuel gauge assembly. Refer to Gauge
Replacement. (2) Check for continuity in the wire between the
fuel tank sending unit and the gauge (fuel level in
put pin) (Figs. 14 and 15). (3) With the ignition switch in the ON position,
check for battery voltage across the B + pin and the Ground pin.