oil temperature DODGE TRUCK 1993 Service Owner's Manual

7 - 38
COOLING
SYSTEM

•
WARNING:
DO NOT
ATTEMPT
TO
BEND
OR

STRAIGHTEN
FAN
BLADES
IF
NOT WITHIN
SPECI­
FICATIONS.

(4) Inspect fan assembly for cracks, bends, loose
rivets or broken welds. Replace fan if any damage is
found.
CAUTION; If the fan
blade assembly
is
replaced
be­

cause
of
mechanical damage,
the fan
pulley
and

viscous
fan
drive should also
be
inspected.
These
components
could have been damaged
due to ex­
cessive
vibration.
INSTALLATION
(1) Install fan blade assembly to viscous fan drive.
Tighten mounting bolts.
(2) Position the fan shroud and fan blade/viscous
fan drive to the vehicle as an assembly.
(3) Install viscous fan drive assembly on fan hub
shaft. Tighten mounting nut to 57 N*m (42 ft. lbs.)
torque.
(4) Install fan shroud bolts.
(5) Install battery cable to battery.

VISCOUS
FAN
DRIVE
The thermal viscous fan drive (Figs. 54 or 55) con­
sists of the viscous fan drive clutch and a thermo­
static spring coil mounted on its front face (Fig. 56).
The viscous fan drive clutch is a silicone-fluid-filled coupling connecting fan blade assembly to water
pump shaft. The coupling allows fan to be driven in a normal manner at low engine speeds. It will limit top
speed of fan to a predetermined maximum level at
higher engine speeds.
The thermostatic spring coil (Fig. 56) reacts to the
temperature of radiator discharge air. It engages drive clutch for higher fan speed if air temperature
from radiator rises above a certain point. Until addi­
tional engine cooling is necessary, fan will remain at a reduced rpm regardless of engine speed. Only when
sufficient heat is present in the air, will the viscous
fan drive clutch engage. This air flowing through ra­ diator core will cause a reaction to thermostatic spring coil. Fan speed will then increase to provide
necessary additional engine cooling.
MOUNTING
NUT

TO WATER PUMP
Fig.
56
Viscous
Fan Drive CAUTION; If
viscous
fan
drive
is
replaced because
of mechanical damage, cooling
fan
blades should

also
be
inspected. Inspect
for
fatigue cracks, loose
blades
or
loose rivets
that
could have resulted
from

excessive
vibration. Replace
fan
blade assembly
if

any
of
these conditions
are
found.
Also
inspect
wa­
ter
pump bearing
and
shaft assembly
for any re­
lated
damage
due to a
viscous
drive malfunction.

Regardless of increased engine speed, once the fan
has reached its maximum operating speed, it will not
rotate any faster. When the necessary engine cooling
has been accomplished causing a reduction in tem­ perature of radiator discharge air, the spring coil again reacts. This will cause fan speed to be reduced
to its previous disengaged speed.
TESTING VISCOUS FAN DRIVE In case of engine overheating, inspect thermal vis­
cous fan drive for proper operation. Observe move­
ment of thermostatic spring coil and shaft. Lift end
of thermostatic spring up and out of retaining slot in
fan drive (Fig. 57). Rotate spring counterclockwise until a stop is felt. The gap between end of coil and
retaining clip should be approximately 12 mm (0.5 inch) (Fig. 58). Replace unit if shaft does not rotate
with coil. After testing, install end of coil in slot of retaining clip.

REMOVAUINSTALLA
TION For removal and installation procedures, refer to
Cooling System Fans in this group.

8A
- 6
ELECTRICAL

•

Fig.
10
Load
50%
Cold
Crank
Rating Note Voltage
LOAD TEST TEMPERATURE

Minimum
Voltage
Temperature

Minimum
Voltage

P c°
9.6 70 and
above
21 and
above

9.5 60
16
9.4 50 10
9.3 40 4
9.1 30 -1
8.9 20 -7
8.7 10 -12
8.5 0
•
18

J908A-4

BATTERY
CHARGING
A battery is completely charged when it has:
• an open circuit voltage of 12.4 volts or more.
• has enough cranking capacity (minimum 9.6 volts
when loaded for 15 seconds to 50% of cold cranking amperage rating at 21°C/70°F). A green color, in the test indicator on the top of the
battery, indicates the battery is charged enough for
further testing. A black color indicates the battery
voltage state of charge is below 75%. A yellow or
bright color indicates the battery has excessively low electrolyte level. The battery cannot be refilled or
charged, it must be replaced.

WARNING:
DO NOT
CHARGE
A
BATTERY
THAT
HAS
EXCESSIVELY
LOW
ELECTROLYTE LEVEL.
BATTERY MAY ARC INTERNALLY AND EXPLODE.
WARNING: EXPLOSIVE GASES FORM OVER BAT­

TERY,
DO NOT
SMOKE, USE FLAME,
OR
CREATE
SPARKS
NEAR BATTERY.
WARNING:
DO
NOT ASSIST BOOST
OR
CHARGE
A
FROZEN BATTERY, CASING MAY FRACTURE. WARNING: POISON, CAUSES SEVERE BURNS.
BATTERY CONTAINS SULFURIC ACID, AVOID CON­

TACT WITH
SKIN,
EYES,
OR
CLOTHING.
IN
EVENT OF CONTACT, FLUSH
WITH
WATER
AND
CALL PHYSICIAN IMMEDIATELY. KEEP
OUT OF
REACH
OF CHILDREN.
CAUTION:
Disconnect
the
vehicle's
battery
negative

cable
before
charging
battery to
avoid
damage
to

electrical
systems.
Do not
exceed
16.0
volts
while
charging
battery.
Battery electrolyte will bubble inside of case while
being charged properly. If the electrolyte boils vio­ lently or is discharged from the vent holes while
charging, immediately reduce charging rate or turn
off charger and evaluate battery condition.
Some battery chargers are equipped with polarity
(+ to +/- to -) sensing devices to protect the charger
or battery from being damaged if improperly con­
nected. If the battery state of charge is too low for
the polarity sensor to detect, the sensor must be by­
passed for charger to operate. Refer to operating in­ structions provided with battery charger being used.

CAUTION:
Charge
battery
until
test
indicator
ap­

pears
green.
Do not
overcharge.

It may be necessary to jostle the battery or vehicle
to bring the green ball into view in the test indicator
when the state-of-charge has reached 75%.
BATTERY CHARGING TIME TABLE

Charging
Amperage
5 Amps
10 Amps
20 Amps

Open
Circuit
Voltage
Hours
Charging
at21°C
(70°F)

12.25
to
12.39
6Hrs.
3Hrs.
1.5
Hr.

12.00
to
12.24
8Hrs.
4Hrs.
2Hrs

11.95
to
12.09
12Hrs.

6Hrs.
3Hrs.

10.00
to
11.95
14Hrs.

7Hrs.
3.5 Hrs.
10.00 to
0
See
Charging
Completely

Discharged
Battery

928A-19

After the battery has been charged, green indica­
tor, perform a load test to determine cranking capac­ ity. If the battery will endure a load test, return the
battery to use. If battery will not endure a load test, it must be replaced. Clean and inspect battery hold
downs, tray, terminals, posts, and top before complet­
ing service, see Group 8B - Battery/Starter/Generator Service.
CHARGING TIME REQUIRED The time required to charge a battery will vary de­
pending upon the following factors:

8A
- 18
ELECTRICAL

• BATTERY SPECIFICATIONS

Load

Test

(Amps)
Cold

Cranking
Rating @ 0°F Reserve
Capacity
300 Amp 600 Amp 120 Minutes
405 Amp 810 Amp 133 Minutes
535 Amp 1075 Amp 170 Minutes

CRANKING
RATING
is the
current
a
battery
can deliver for 30
seconds
and maintain a
terminal
voltage of 7.2 volts or greater at specified
temperature.

RESERVE
CAPACITY RATING
is the length of
time
a
battery
can deliver 25 amps and maintain a minimum
terminal
voltage of 10.5 volts
at27°C
(80 °F).
J938A-25 GAS ENGINE STARTER
DIESEL ENGINE STARTER
Manufacturer
Nippondenso

Engine
Application 5.9L, 5.21 e\ 3.9L
Part Number and
53005984

Power Rating 1.4 Kw
Voltage 12

No.
of Fields 4

No.
of
Poles.
4

Brushes
4
Drive Reduction
Gear Train

Free
Running Test Voltage 11
Amperage Draw ............ 73
Amps

Minimum Speed rpm 3601 rpm

Solenoid
Closing
Voltage 7.5 Volts
Cranking Amperage Draw Test . . .
125-200
Amps*

*
Engine
should
be up to operating
temperature.
Extremely heavy oil or tight engine
will
increase
starter
amperage draw.
J938B-14
REDUCTION
GEAR
STARTER

Manufacturer
Nippondenso

Engine
Application 5.9L
Part Number and Power Rating ..............
4428221

3
kw
Voltage 12

No.
of Fields 4

No.
of
Poles
4

Brushes
.................... 4
Drive Conventional
Gear Train

Free
Running Test Voltage .
Amperage Draw
Minimum Speed rpm 11
220
Amps
Max.
4200
rpm Min.

Solenoid
Closing
Voltage. 8 Volts
Cranking Amperage Draw Test . .
450-550
Amps*

*
Engine
should be up to operating heavy oil or tight engine
will
increase
temperature.
Extremely

starter
amperage draw. J918B-21

SPECIFICATIONS

•
BATTERY/STARTER/GENERATOR
SERVICE
8B - 9

Load

Test

(Amps)
cold

Cranking
Rating
@ 0°F
Reserve
Capacity
300 Amp 600 Amp 120 Minutes
405 Amp 810 Amp 133 Minutes
535 Amp 1075 Amp
170 Minutes

CRANKING
RATING
is the
current
a
battery
can
deliver
for 30
seconds
anej
maintain
a
terminal
voltage
of 7.2
volts
or
greater
at
specified
temperature.

RESERVE
CAPACITY RATING
is the
length
of
time
a
battery
can
deliver
25
amps and maintain
a
minimum
terminal
voltage
of
10.5 volts
at
27 °C (80
°F).

J938A-25

GAS ENGINE DIESEL ENGINE

Manufacturer
Nippondenso

Engine
Application 5.9L, 5.2L
&
3.9L
Part Number and
53005984

Power Rating
1.4
Kw
Voltage
12

No.
of
Fields 4

No.
of
Poles. 4

Brushes
4
Drive Reduction
Gear
Train

Free
Running Test Voltage 11
Amperage Draw 73 Amps
Minimum Speed
rpm
3601
rpm

Solenoid
Closing Voltage 7.5 Volts
Cranking Amperage Draw Test
. . .
125-200
Amps*

*
Engine
should be up to operating
temperature.
Extremely heavy oil
or
tight engine
will
increase
starter
amperage draw.
J938B-14
REDUCTION
GEAR
STARTER

Manufacturer
Nippondenso

Engine
Application 5.9L
Part Number
and
Power Rating
4428221

3
kw

Voltage
12

No.
of
Fields
4

No.
of
Poles 4

Brushes
4
Drive Conventional
Gear Train

Free
Running Test Voltage
Amperage Draw
Minimum Speed
rpm
11
220 Amps Max.
4200
rpm Min.

Solenoid
Closing Voltage 8 Volts
Cranking Amperage Draw Test
. .
450-550
Amps*

*
Engine
should
be up to
operating
temperature.
Extremely heavy oil or tight engine
will
increase
starter
amperage draw.
J918B-21

GENERATOR SPECIFICATIONS
TYPE

PHUT
HUMSIR
PULLEY
GROOVES

ENGINE
RATING

NIPPONDENSO
53008646
7
ALL GASOLINE 75 AMPS

NIPPONDENSO
53008647
7
ALL GASOLINE 90 AMPS

NIPPONDENSO
53008651
7
ALL GASOLINE
120
AMPS

NIPPONDENSO
5234374
8
DIESEL
120 AMPS
J938B-28
SPECIFICATIONS

BATTERY SPECIFICATIONS

•

IGNITION
SYSTEMS
8D
- 1
CONTENTS

page page
COMPONENT IDENTIFICATION/SYSTEM DIAGNOSTICS/SERVICE PROCEDURES
7
OPERATION
1
IGNITION SWITCH
25

COMPONENT REMOVAL/INSTALLATION
..... 18
SPECIFICATIONS
28

COMPONENT
IDENTIFICATION/SYSTEM OPERATION
INDEX
page

Automatic
Shut Down (ASD) Relay
1
Camshaft Position Sensor
2

Crankshaft Position Sensor
2

Distributors
3

Engine Coolant
Temperature
Sensor
...........
4

General
Information
1
page

Ignition
Coil
3
Intake
Manifold Charge
Air
Temperature
Sensor
. . 4

Manifold Absolute Pressure (MAP) Sensor
4
Powertrain
Control
Module (PCM)
. 5

Throttle
Position Sensor
5

GENERAL
INFORMATION
Throughout this group, references
are
made
to
par­
ticular vehicle models
by
alphabetical designation
or

by
the
particular vehicle nameplate.
A
chart showing a breakdown
of
alphabetical designations
is
included
in
the
Introduction group
at the
beginning
of
this
manual. 5.9L
gas
powered engines will
be
referred
to as ei­

ther: LDC (Light Duty Cycle),
or
HDC (Heavy Duty Cycle). This section
of the
group, Component Identifica­
tion/System Operation, will discuss ignition system operation
and
will identify ignition system compo­

nents.
For diagnostic procedures
and
adjustments, refer
to

the Diagnostics/Service Procedures section
of
this
group.
For removal
and
installation
of
ignition system
components, refer
to the
Component Removal/Instal­
lation section
of
this group. For other useful information, refer
to
On-Board
Di­

agnostics
in the
General Diagnosis sections
of
Group
14,
Fuel System
in
this manual. For operation
of the DRB II
Diagnostic Scan Tool,
refer
to the
appropriate Powertrain Diagnostic Proce­
dures service manual.
An Ignition specifications section
is
included
at the

end
of
this group.
A
general Maintenance Schedule (mileage intervals)
for
ignition related items
can be
found
in
Group
0,
Lubrication and Maintenance. This
schedule
can
also
be
found
in the
Owners Manual.

IGNITION
SYSTEMS
The ignition systems used
on all
engines
are
basi­
cally identical. Similarities
and
differences between
the systems will
be
discussed.
A sequential multi-port fuel injection system
is

used
on all gas
powered engines.
The ignition system
is
controlled
by the
powertrain
control module (PCM)
on all
engines.
The
PCM
was

formerly referred
to as the
SBEC
or
engine control­ ler.
The ignition system consists
of:

• Spark Plugs
• Ignition Coil
• Secondary Ignition Cables
• Ignition distributor. Contains rotor
and
camshaft
position sensor • Powertrain Control Module (PCM)
• Crankshaft Position Sensor

AUTOMATIC SHUT DOWN (ASD) RELAY
The automatic shut down (ASD) relay
is
located
in

the engine compartment (Fig.
1). As one of its
func­

tions,
the ASD
relay will supply battery voltage
to
the ignition coil.
The
ground circuit
for the
ASD
re­

lay
is
controlled
by the
powertrain control module (PCM).
The PCM
regulates
ASD
relay operation
by
switching
the
ground circuit on-and-off.

IGNITION
SYSTEMS

8D
- 4
IGNITION
SYSTEMS

•
Fig. 6 ignition Coil—3.9L/5.2L/5.9L
LDC-Gas
Engines Fig. 7 Ignition Coil—5.9L
HDC-Gas
Engine
• 5.9L HDC-Gas Engines: The coil is mounted to a
bracket that is bolted to the automatic belt tensioner mounting bracket (Fig. 7).
For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group.
For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.

ENGINE COOLANT TEMPERATURE
SENSOR
The sensor provides an input voltage to the power-
train control module (PCM) relating coolant temper­ ature. The PCM uses this input, along with inputs
from other sensors, to determine injector pulse width and ignition timing. As coolant temperature varies,
the coolant temperature sensor resistance will
change, resulting in a different input voltage to the
PCM. When the engine is cold, the PCM will operate in
the Open Loop Cycle. It will demand slightly richer air-fuel mixtures and higher idle speeds, until nor­ mal operating temperatures are reached. Refer to
Modes Of Operation in Group 14, Fuel System for a
description of Open and Closed Loop operation.
The sensor is installed in the intake manifold near
the thermostat housing (Fig. 8).
Fig. 8 Coolant Temperature Sensor—Typical
For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group. For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.

INTAKE MANIFOLD CHARGE
AIR
TEMPERATURE

SENSOR
The sensor element extends into the intake mani­
fold air stream. It provides an input voltage to the
powertrain control module (PCM) indicating intake
manifold air temperature. The input from this sensor is used along with inputs from other sensors to de­
termine injector pulse width. As the temperature of
the air-fuel stream in the manifold varies, the sensor
resistance will change. This will result in a different input voltage to the PCM. For more information, re­
fer to Group 14, Fuel System. This sensor is installed in the intake manifold

(Figs.
9 or 10). For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group. For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.

MANIFOLD ABSOLUTE
PRESSURE
(MAP)
SENSOR
The MAP sensor reacts to absolute pressure in the
intake manifold and provides an input voltage to the
powertrain control module (PCM). As engine load changes, manifold pressure varies, causing the MAP
sensor voltage to change. This change results in a
different input voltage to the PCM. The input volt­ age level supplies the PCM with information. This
relates to ambient barometric pressure during engine

•

IGNITION
SYSTEMS
8D - 5

THROTTLE
^
BODY
u

BRACKET
y^SUPPORT
BRACKET
/ |

CHARGE
AIR

ijmmmmk
TEMPERATURE
SENSOR
THROTTLE

BODY

Fig.
9
Sensor
Location—3.9L Engine—Typical
INTAKE MANIFOLD
'b AIR TEMPERATURE

SENSOR

J9314-162

Fig.
10
Sensor
Location—5.2L/5.9L
Engines—Typical
start-up (cranking) and to engine load while the en­
gine is running. The PCM uses this input, along with
inputs from other sensors, to adjust air-fuel mixture.
For more information, refer to Group 14, Fuel Sys­
tem.
The MAP sensor is mounted to the throttle body
(Fig. 11). It is connected to the throttle body with an
L-shaped rubber fitting and to the PCM electrically. For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group. For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.

POWERTRAIN CONTROL MODULE
(PCM) The powertrain control module (PCM) is located in
the engine compartment behind the battery (Fig. 12).
The PCM was formerly referred to as the SBEC or engine controller. The ignition system is controlled by the PCM. Base ignition timing by rotation of distributor
is not adjustable.
MANIFOLD

ABSOLUTE
PRESSURE
SENSOR

TORQUE CONVERTER CLUTCH RELAY
ELECTRICAL
Jlp^

CONNECTOR
^gis!—

Fig.
11 MAP Sensor—Typical
A/C
CLUTCH RELAY STARTER RELAY
AUTO
SHUTDOWN RELAY FUEL PUMP RELAY
DATA LINK
CONNECTOR POWERTRAIN
CONTROL
MODULE
J9314-164

Fig.
12 PCM Location—Typical The PCM opens and closes the ignition coil ground
circuit to operate the ignition coil. This is done to ad­
just ignition timing, both initial (base) and advance, for changing engine operating conditions.
The amount of electronic spark advance provided
by the PCM is determined by five input factors: Cool­ ant temperature, engine rpm, intake manifold tem­
perature, manifold absolute pressure and throttle
position.
For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.
For diagnostics, refer to the appropriate Powertrain
Diagnostic Procedures service manual for operation
of the DRB II scan tool.

THROTTLE
POSITION
SENSOR
The sensor is mounted on the throttle body (Fig.

13).
It is connected to the throttle blade shaft. The
sensor is a variable resistor. It provides the power-
train control module (PCM) with an input signal (voltage) that represents throttle blade position. As

•

IGNITION
SYSTEMS
80 - 7
DIAGNOSTICS/SERW1CE
PROCEDURES

INDEX

page

Automatic Shut Down (ASD) Relay
7
Camshaft Position
Sensor
Test
...............
7

Crankshaft Position
Sensor
Test
8

Distributor
Cap
8

Distributor
Rotor
8
Engine
Coolant Temperature
Sensor
Test
10

General
Information
7

Ignition
Coil
8

Ignition
Secondary
Circuit
Diagnosis
10

GENERAL
INFORMATION
This section
of the
group, Diagnostics/Service Pro­
cedures, will discuss basic ignition system diagnos­
tics
and
service adjustments. For system operation
and
component identification,
refer
to the
Component Identification/System Opera­
tion section
of
this group. For removal
or
installation
of
ignition system com­
ponents, refer
to the
Component Removal/Installa­
tion section
of
this group. For other useful information, refer
to
On-Board
Di­

agnostics
in the
General Diagnosis sections
of
Group
14,
Fuel System
in
this manual. For operation
of the DRB II
Diagnostic Scan Tool,
refer
to the
appropriate Powertrain Diagnostic Proce­
dures service manual.

AUTOMATIC SHUT DOWN
(ASD)
RELAY
Refer
to
Relays—Operation/Testing
in the
Group

14,
Fuel System section
of
this service manual.

CAMSHAFT POSITION SENSOR TEST
The camshaft position sensor
is
located
in the
dis­
tributor
on all
engines. To perform
a
complete test
of
this sensor
and its

circuitry, refer
to the DRB II
diagnostic scan tool.
Also refer
to the
appropriate Powertrain Diagnostics
Procedures manual.
To
test
the
sensor only, refer
to

the following: For this test,
an
analog (non-digital) voltmeter
is needed.
Do not
remove
the
distributor connector from
the
distributor. Using small paper clips, insert
them into
the
backside
of the
distributor wire har­ ness connector
to
make contact with
the
terminals.
Be sure that
the
connector
is not
damaged when
in­
serting
the
paper clips. Attach voltmeter leads
to

these paper clips. (1) Connect
the
positive (
+
)
voltmeter lead into
the sensor output wire. This
is at
done
the
distribu­ tor wire harness connector.
For
wire identification,
refer
to
Group
8W,
Wiring Diagrams.
page

Ignition
Timing
12

Intake Manifold Charge
Air
Temperature
Sensor
Test
12

Manifold Absolute Pressure (MAP)
Sensor
Test
. 12

Oxygen
Sensor
Tests
17
Powertrain Control Module (PCM)
............
14

Spark
Plug Secondary Cables
16

Spark
Plugs
............................
14

Throttle
Position
Sensor
Test
17

(2) Connect
the
negative
(-)
voltmeter lead into
the

ground wire.
For
wire identification, refer
to
Group
8W, Wiring Diagrams.
(3)
Set the
voltmeter
to the 15
Volt
DC
scale. (4) Remove distributor
cap
from distributor
(two

screws). Rotate (crank)
the
engine until
the
distribu­
tor rotor
is
pointed towards
the
rear
of
vehicle.
The

movable pulse ring should
now be
within
the
sensor
pickup.
(5) Turn ignition
key to ON
position. Voltmeter
should read approximately
5.0
volts.
(6)
If
voltage
is not
present, check
the
voltmeter
leads
for a
good connection.
(7)
If
voltage
is
still
not
present, check
for
voltage
at
the
supply wire.
For
wire identification, refer
to

Group
8W,
Wiring Diagrams.
(8)
If
voltage
is not
present
at
supply wire, check
for voltage
at
pin-7
of
powertrain control module (PCM) 60-way connector. Leave
the PCM
connector
connected
for
this test. (9)
If
voltage
is
still
not
present, perform vehicle
test using
the DRB II
diagnostic scan tool. (10)
If
voltage
is
present
at
pin-7,
but not at the

supply wire: (a) Check continuity between
the
supply wire.
This
is
checked between
the
distributor connector and pin-7
at the PCM. If
continuity
is not
present,
repair
the
harness
as
necessary. (b) Check
for
continuity between
the
camshaft
position sensor output wire
and
pin-44
at the PCM.
If continuity
is not
present, repair
the
harness
as
necessary. (c) Check
for
continuity between
the
ground cir­
cuit wire
at the
distributor connector
and
ground.
If continuity
is not
present, repair
the
harness
as
necessary. (11) While observing
the
voltmeter, crank
the en­

gine with ignition switch.
The
voltmeter needle should fluctuate between
0 and 5
volts while
the en­

gine
is
cranking. This verifies that
the
camshaft
po­
sition sensor
in the
distributor
is
operating properly
and
a
sync pulse signal
is
being generated.

8D
- 10
IGNITION
SYSTEMS

• Arcing at the tower will carbonize the cable boot,
which if it is connected to a new ignition coil, will cause the coil to fail. If the secondary coil cable shows any signs of dam­

age,
it should be replaced with a new cable and new
terminal. Carbon tracking on the old cable can cause
arcing and the failure of a new ignition coil.

ENGINE
COOLANT
TEMPERATURE
SENSOR
TEST
To perform a complete test of this sensor and its
circuitry, refer to the DRB II diagnostic scan tool.
Also refer to the appropriate Powertrain Diagnostics
Procedures manual. To test the sensor only, refer to
the following: The sensor is located in a water passage of the in­
take manifold next to the thermostat housing (Fig.
8).
(1) Disconnect wire harness connector from sensor
(Fig. 8). On engines with air conditioning, do not pull
directly on wiring harness. Fabricate an L-shaped
hook tool from a coat hanger (approximately eight inches long). Place the hook part of tool under the
connector for removal. The connector is snapped onto
the sensor. It is not equipped with a lock type tab.
COOLANT

TEMPERATURE
SENSOR
SENSOR RESISTANCE (OHMSJ
V

J9314-78

Fig. 8 Coolant Temperature Sensor—Typical (2) Test the resistance of the sensor with a high in­
put impedance (digital) volt-ohmmeter. The resis­ tance should be less than 1340 ohms at normal
engine operating idle temperature. For resistance
values, refer to the Sensor Resistance chart. Replace
the sensor if it is not within the range of resistance specified in the chart.
(3) Test continuity of the wire harness. This is
done between powertrain control module (PCM) wire
harness connector terminal-2 and the sensor connec­
tor terminal. Also check continuity between wire harness terminal-4 to the sensor connector terminal. Repair the wire harness if an open circuit is indi­
cated.
TEMPERATURE

RESISTANCE
(OHMS)

C
F
MIN
MAX

-40 -40 291,490 381,710
-20
-4
85,850
108,390
-10 14
49,250 61,430

0
32 29,330
35,990
10 50 17,990 21,810
20 68 11,370 13,610

25
77 9,120 10,880
30 86
7,370

8,750

40 104

4,900
5,750

50 122
3,330 3,880

60 140 2,310

2,670

70 158
1,630 1,870

80 176
1,170 1,340

90 194
860
970
100 212 640
720
110 230 480 540
120 248 370 410

J928D-4

IGNITION
SECONDARY
CIRCUIT
DIAGNOSIS

CHECKING FOR SPARK

CAUTION:
When
disconnecting a
high
voltage
cable

from
a spark
plug
or
from
the
distributor
cap,
twist
the rubber
boot
slightly
(1/2
turn)
to
break
it
loose.
Grasp
the
boot
(not the cable) and
pull
it off
with
a

steady,
even force.

(1) Disconnect the ignition coil secondary cable
from center tower of the distributor cap. Hold the ca­
ble terminal approximately 12 mm (1/2 in.) from a good engine ground (Fig. 9).
CHECK
HERE

FOR
SPARK
IGNITION

COIL
918D-18

Fig. 9 Checking for Spark—Typical

8D
- 12
IGNITION
SYSTEMS

•

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3%
lOOOOOOOOOO
OOOOOOOOOO

si
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fcji^OQOOOOOOJ

«r
~
• • -
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- - #
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CONNECTOR

TERMINAL
SIDE
SHOWN
J908D-42
Fig. 13 PCM 60-Way Connector
(6) Make the special jumper shown in Figure 14.
Using the jumper, momentarily ground terminal-19
of the 60-way connector. A spark should be generated at the coil cable when the ground is removed.
CAPACITOR

GROUND
THIS
CLIP
CONNECT
THIS-

ALLIGATOR
CLIP

MOMENTARILY
GROUND
THIS
CLIP
TO
COIL^
NEGATIVE

ALLIGATOR
CLIP
PR1003

Fig. 14 Special Jumper Ground-to-Coil Negative Terminal (7) If spark is generated, replace the powertrain
control module (PCM).
(8) If spark is not seen, use the special jumper to
ground the coil negative terminal directly. (9) If spark is produced, repair wiring harness for
an open condition. (10) If spark is not produced, replace the ignition
coil.

IGNITION TIMING
Base (Initial) ignition timing Is NOT adjustable
on any engine. Do not attempt to adjust Ignition
timing by rotating the distributor. All ignition timing functions are controlled by the
powertrain control module (PCM). Refer to On-Board Diagnostics in the Multi-Port Fuel Injection—Gen­
eral Diagnosis section of Group 14, Fuel Systems for
more information. Also refer to the appropriate Pow­ ertrain Diagnostics Procedures service manual for
operation of the DRB II Scan Tool.

INTAKE
MANIFOLD
CHARGE
AIR
TEMPERATURE

SENSOR
TEST
To perform a complete test of this sensor and its
circuitry, refer to the DRB II diagnostic scan tool.
Also refer to the appropriate Powertrain Diagnostics Procedures manual. To test the sensor only, refer to
the following: (1) Disconnect the wire harness connector from the
sensor (Figs. 15 or 16).
THROTTLE
^

BODY
^

BRACKET
SUPPORT BRACKET
/

CHARGE
AIR

TEMPERATURE
SENSOR

Fig. 15 Sensor Location--3.9L Engine—Typical
INTAKE
MANIFOLD
AIR
TEMPERATURE

W
SENSOR

J9314-162

Fig. 16
Sensor
Location—5.2U5.9L
Engines—Typical
(2) Test the resistance of the sensor with a input
impedance (digital) volt-ohmmeter. Do not remove
the sensor from the engine for testing. For resistance
values, refer to the Sensor Resistance chart. Replace
the sensor if it is not within the range of resistance specified in the chart.
(3) Test the resistance of the wire harness. This is
done between the powertrain control module (PCM)
wire harness connector terminal-2 and the sensor connector terminal. Also check continuity between
terminal-4 to the sensor connector terminal. Repair
the wire harness as necessary if the resistance is greater than 1 ohm.
For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.

MANIFOLD
ABSOLUTE PRESSURE
(MAP)
SENSOR
TEST
To perform a complete test of MAP sensor (Fig. 17)
and its circuitry, refer to DRB II tester and appropri-