1993 DODGE TRUCK Service Repair Manual

8D
- 18
IGNITION
SYSTEMS

•
COMPONENT REMGWAL/INSTALLATION

INDEX

page

Automatic
Shut Down (ASD) Relay
18
Camshaft
Position
Sensor
, 18

Crankshaft Position
Sensor
18
Distributor
Service
20
Engine
Coolant Temperature
Sensor
20

General
Information
18
Ignition
Coil
21
page

Intake
Manifold Charge
Air
Temperature
Sensor
. 22

Manifold Absolute Pressure (MAP)
Sensor
..... 22

Oxygen
(02)
Sensor
22
Powertrain
Control
Module (PCM)
22

Spark
Plug Secondary Cables
24

Spark
Plugs
23

Throttle
Position
Sensor
(TPS)
24

GENERAL
INFORMATION
This section
of the
group, Component Removal/In­
stallation, will discuss
the
removal
and
installation
of ignition system components. For basic ignition system diagnostics
and
service
adjustments, refer
to the
Diagnostics/Service Proce­
dures section
of
this group. For system operation
and
component identification,
refer
to the
Component Identification/System Opera­
tion section
of
this group.

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

the engine compartment
(Fig. 1).
TORQUE CONVERTER
CLUTCH RELAY
A/C
CLUTCH RELAY STARTER RELAY

AUTO
SHUTDOWN RELAY FUEL PUMP RELAY DATA UNK
CONNECTOR POWERTRAIN
CONTROL
MODULE
J9314-164

Fig.
1
Auto
Shut Down
Relay
REMOVAL

(1) Disconnect negative battery cable
at
battery.

(2)
Remove
the
relay
by
pulling from connector.

INSTALLATION
(1) Check
the
terminals
in the
relay connector
for

corrosion
or
damage before installation.

(2)
Push
the
relay into
the
connector.

CAMSHAFT POSITION SENSOR
The camshaft position sensor
is
located
in the
dis­
tributor
(Fig. 2).
REMOVAL

Distributor removal
is not
necessary
to
remove
camshaft position sensor.

CAMSHAFT POSITION
SENSOR
SYNC

SIGNAL

GENERATOR
DISTRIBUTOR
ASSEMBLY
J9314-82

Fig.
2
Camshaft Position Sensor—Typical
(1) Disconnect negative battery cable
at
battery.

(2)
Remove distributor
cap
from distributor
(two

screws).
(3) Disconnect camshaft position sensor wiring
harness from main engine wiring harness.
(4) Remove distributor rotor from distributor shaft.

(5)
Lift
the
camshaft position sensor assembly from
the distributor housing
(Fig. 2).

INSTALLATION
(1) Install camshaft position sensor
to
distributor.
Align sensor into notch
on
distributor housing.
(2)
Connect wiring harness.
(3) Install rotor.
(4) Install distributor
cap.
Tighten mounting
screws.

CRANKSHAFT
POSITION SENSOR
REMOVAL The sensor
is
bolted
to the top of the
cylinder block
near
the
rear
of
right cylinder head
(Fig. 3).

•

Fig.
3 Crankshaft Position Sensor—Typical (1) Remove the spark plug cable loom and spark
plug cables from valve cover mounting stud at rear of right valve cover (Fig. 3). Position spark plug ca­
bles to top of valve cover.
(2) Disconnect 2 hoses at Exhaust Gas Recircula­
tion (EGR) valve. Note position of hoses at EGR valve before removal.
(3) Disconnect electrical connector and hoses at
electric EGR transducer (EET). Note position of
hoses at EET before removal.
(4) Remove 2 EGR valve mounting bolts and re­
move EGR valve. Discard old EGR gasket.
(5) Disconnect electrical connector at engine oil
pressure sending unit.
(6) To prevent damage to oil pressure sending unit,
a special tool, such as number C-4597 must be used (Fig. 4). Remove sending unit from engine.
(7) Loosen EGR tube mounting nut at intake man­
ifold.
(8) Remove 2 EGR tube mounting bolts at exhaust
manifold (Fig. 3) and remove EGR tube. Discard old
gasket at exhaust manifold.
(9) Disconnect crankshaft position sensor pigtail
harness from main wiring harness.
(10) Remove 2 sensor (recessed hex head) mount­
ing bolts (Fig. 3) and remove sensor.

INSTALLATION
(1) Position crankshaft position sensor to engine
and install mounting bolts. Tighten bolts to 8 N#m (70 in. lbs.) torque. (2) Connect main harness electrical connector to
sensor.
IGNITION
SYSTEMS
80-19

Fig.
4 Oil
Pressure
Sending
Unit—Removal/Installation (3) Clean the EGR tube and exhaust manifold (at
EGR tube mounting point) of any old gasket mate­

rial.
(4) Install a new gasket to exhaust manifold end of
EGR tube and install EGR tube to both manifolds.
Tighten mounting nut at intake manifold. Tighten 2 mounting bolts at exhaust manifold to 23 N#m (204 in. lbs.) torque.
(5) Coat the threads of the oil pressure sending
unit with thread sealant. Do not allow any of the
thread sealant to get into the sending unit opening, or the opening at the engine. Install sending unit to
engine and tighten to 14 N»m (130 in. lbs.) torque.
Install electrical connector to sending unit.
(6) Clean the intake manifold and EGR valve of
any old gasket material.
(7) Install a new EGR valve gasket at intake man­
ifold. (8) Install EGR valve to intake manifold. Tighten
2 bolts to 23 N«m (200 in. lbs.) torque.
(9) Position EET and install its electrical connec­
tor. Connect hoses between EGR valve and EET. Connect hose between main vacuum harness and
EET.
(10) Install spark plug cable loom and spark plug
cables to valve cover mounting stud.

8D
- 20
IGNITION
SYSTEMS

•
ENGINE
COOLANT
TEMPERATURE
SENSOR

WARNING: HOT, PRESSURIZED COOLANT CAN CAUSE INJURY BY SCALDING. COOLING SYSTEM MUST BE PARTIALLY DRAINED BEFORE REMOV­
ING THE COOLANT TEMPERATURE SENSOR. RE­
FER TO GROUP 7, COOLING.

REMOVAL
(1) Partially drain cooling system. Refer to Group
7, Cooling.

(2)
Disconnect electrical connector from sensor
(Fig. 5). Engines with air conditioning: When removing
the connector from sensor, 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 sen­ sor. It is not equipped with a lock type tab.
(3) Remove sensor from intake manifold.
Fig. 5 Coolant Temperature
Sensor—
Typical

INSTALLATION
(1) Install sensor.
(2) Tighten to 7 Nnn (5.5 ft. lbs.) torque.
(3) Connect electrical connector to sensor.
The sensor connector is symmetrical (not indexed).
It can be installed to the sensor in either direction. (4) Replace any lost engine coolant. Refer to Group
7, Cooling System.

DISTRIBUTOR
SERVICE

REMOVAL

CAUTION:
Base
ignition timing
is not
adjustable
on

any
engine. Distributors
do not
have
built
in
centrif­
ugal
or
vacuum assisted advance.
Base
ignition
timing
and
timing advance
are
controlled
by the
powertrain control module
(PCM).
Because
a
con­
ventional timing light can
not be
used
to
adjust
dis­

tributor
position
after
installation, note position
of
distributor before removal.

(1) Disconnect negative battery cable at battery.
(2) Remove distributor cap from distributor (two
screws).
(3) Mark the position of distributor housing in
relationship to engine or dash panel. This is done
to aid in installation. Before distributor is removed, the number one cyl­
inder must be brought to the top dead center (TDC)
firing position. (4) Attach a socket to the Crankshaft Vibration
Damper mounting bolt.
(5) Slowly rotate engine clockwise, as viewed from
front, until indicating mark on crankshaft vibration damper is aligned to 0 degree (TDC) mark on timing
chain cover (Fig. 6).
Fig. 6 Damper-To-Cover Alignment Marks—Typical (6) The distributor rotor should now be aligned to
the CYL. NO. 1 alignment mark (stamped) into the camshaft position sensor (Fig. 7). If not, rotate the
crankshaft through another complete 360 degree

turn.
Note the position of the number one cylinder spark plug cable (on the cap) in relation to rotor. Ro­
tor should now be aligned to this position.
(7) Disconnect camshaft position sensor wiring
harness from main engine wiring harness.
(8) Remove distributor rotor from distributor shaft. (9) Remove distributor holddown clamp bolt and
clamp (Fig. 8). Remove distributor from vehicle.
CAUTION: Do not
crank engine
with
distributor
re­
moved.
Distributor/crankshaft relationship
will
be

lost.

IGNITION
SYSTEMS
80 - 21

DISTRIBUTOR
J9314-81
Fig.
7 Rotor Alignment Mark Fig. 8 Distributor Holddown Clamp

INSTALLATION
If engine has been cranked while distributor is re­
moved, establish the relationship between distributor shaft and number one piston position as follows:
Rotate crankshaft in a clockwise direction, as
viewed from front, until number one cylinder piston is at top of compression stroke (compression should
be felt on finger with number one spark plug re­ moved). Then continue to slowly rotate engine clock­
wise until indicating mark (Fig. 6) is aligned to 0
degree (TDC) mark on timing chain cover.
(1) Clean top of cylinder block for a good seal be­
tween distributor base and block.
(2) Lightly oil the rubber O-ring seal on the dis­
tributor housing.
(3) Install rotor to distributor shaft.
(4) Position distributor into engine to its original
position. Engage tongue of distributor shaft with slot in distributor oil pump drive gear. Position rotor to
the number one spark plug cable position.
(5) Install distributor holddown clamp and clamp
bolt. Do not tighten bolt at this time. (6) Rotate the distributor housing until rotor is
aligned to CYL. NO. 1 alignment mark on the cam­
shaft position sensor (Fig. 7).
(7) Tighten clamp holddown bolt (Fig. 8) to 22.5
N*m (200 in. lbs.) torque. (8) Connect camshaft position sensor wiring har­
ness to main engine harness. (9) Install distributor cap. Tighten mounting
screws.

IGNITION
COIL
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.

REMOVAL
3.9L/5.2L/5.9L LDC-Gas Engines: The coil is
mounted to a bracket that is bolted to the front of
the right engine cylinder head (Fig. 9). This bracket is also used to mount the automatic belt tensioner.
5.9L HDC-Gas Engines: The coil is mounted to a
bracket that is bolted to the automatic belt tensioner mounting bracket (Fig. 10).

Fig.
9 Ignition Coil-3.9U5.2U5.9L
LDC-Gas
Engines
Fig.
10 Ignition Coil—5.9L
HDC-Gas
Engine

8D
- 22
IGNITION
SYSTEMS

• (1) Disconnect the wiring and secondary cable from
the ignition coil (Figs. 9 or 10).

WARNING:
(3.9L/5.2L/5.9L
LDC-GAS ENGINES)
DO
NOT REMOVE
THE
COIL MOUNTING BRACKET-TO-
CYLINDER HEAD MOUNTING BOLTS.
THE
COIL MOUNTING BRACKET
IS
UNDER ACCESSORY
DRIVE BELT TENSION.
IF
THIS BRACKET
IS TO BE
REMOVED
FOR ANY
REASON,
ALL
BELT TENSION
MUST FIRST
BE
RELIEVED. REFER
TO THE
BELT
SECTION
OF
GROUP
7,
COOLING SYSTEM.

(2) Remove ignition coil from coil mounting
bracket (two bolts).
INSTALLATION (1) Install the ignition coil to coil bracket. If nuts
and bolts are used to secure coil to coil bracket,
tighten to 11 N«m (100 in. lbs.) torque. If the coil mounting bracket has been tapped for coil mounting

bolts,
tighten bolts to 5 N«m (50 in. lbs.) torque.
(2) Connect all wiring to ignition coil.

INTAKE MANIFOLD CHARGE
AIR
TEMPERATURE

SENSOR

REMOVAL The charge air temperature sensor is located in
right-front side of intake manifold (Figs. 11 or 12).
Fig.
11
Sensor
Location—3.9L Engine—Typical
(1) Disconnect electrical connector at sensor (Figs.
11 or 12).
(2) Remove sensor from intake manifold.
INSTALLATION (1) Install sensor to intake manifold. (2) Tighten the sensor to 13 N-m (10 ft. lbs.)
torque. (3) Install electrical connector.
Fig.
12
Sensor
Location—5.2L/5.9L

Engines—Typical
MANIFOLD ABSOLUTE
PRESSURE
(MAP)
SENSOR

For removal and installation, refer to Manifold Ab­
solute Pressure Sensor in group 14, Fuel Systems.

OXYGEN
(02)
SENSOR
For diagnostics and removal/installation proce­

dures,
refer to Group 14, Fuel Systems, in this man­

ual.
POWERTRAIN CONTROL MODULE
(PCM)
REMOVAL The PCM is located in the engine compartment be­
hind the battery and under the left front fender (Fig.

13).
DATA
UNK CONTROL
CONNECTOR MODULE
J9314-164

Fig.
13 PCM Location—Typical (1) Disconnect negative battery cable at battery.
(2) Disconnect positive battery cable at battery.
(3) Remove battery holddown clamps and remove
battery.
(4) Remove 60-way electrical connector from PCM.
(5) Remove the three PCM mounting bolts (Fig.

14).

•

IGNITION
SYSTEMS
80 - 23

PCM

MOUNTING

PCM CONNECTOR CONNECTOR
MOUNTING
BOLT
J9314-165

Fig.
14 PCM Removal/Installation
(6) Remove PCM from vehicle.
INSTALLATION

(1) Check pins in PCM 60-way connector for dam­

age.
Repair as necessary. (2) Position PCM and install mounting bolts.
Tighten bolts to 4 N»m (35 in. lbs.) torque. (3) Connect 60-way electrical connector to the
PCM. (4) Install battery.
(5) Connect battery cables to battery (positive ca­
ble first).

SPARK
PLUGS
Spark plug cable heat shields are pressed into the
cylinder head to surround each cable boot and spark
plug (Fig. 15). These shields protect the spark plug
boots from damage (due to intense engine heat gen­ erated by the exhaust manifolds) and should not be
removed. After the spark plug cable has been in­ stalled, the lip of the cable boot should have a small
air gap to the top of the heat shield (Fig. 15). If removal of the heat shield(s) is necessary, re­
move the spark plug cable and compress the sides of
shield for removal. Each shield is slotted to allow for
compression and removal. To install the shields, align shield to machined opening in cylinder head
and tap into place with a block of wood.

PLUG
REMOVAL
(1) Always remove spark plug or ignition coil ca­
bles by grasping at the cable boot. Turn the cable
boot 1/2 turn and pull straight back in a steady mo­
tion. Never pull directly on the cable. Internal dam­ age to cable will result.
Fig.
15 Heat
Shields

(2) Prior to removing the spark plug, spray com­
pressed air around the spark plug hole and the area around the spark plug. This will help prevent foreign
material from entering the combustion chamber.
(3) Remove the spark plug using a quality socket
with a rubber or foam insert. (4) Inspect the spark plug condition. Refer to
Spark Plugs in the Diagnostics/Service Procedures
section of this group.
PLUG CLEANING The plugs may be cleaned using commercially
available spark plug cleaning equipment. After
cleaning, file the center electrode flat with a small
point file or jewelers file before adjusting gap.
PLUG GAP ADJUSTMENT Check the spark plug gap with a gap gauge tool. If
the gap is not correct, adjust it by bending the
ground electrode (Fig. 16). Never attempt to adjust
the gap by bending the center electrode.

SPARK
PLUG
GAP All Engines: .89 mm (.035 in).
PLUG INSTALLATION Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap.
When replacing the spark plug and ignition coil ca­

bles,
route the cables correctly and secure them in
the appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition noise. It could cause cross ignition of the spark plugs,
or short circuit the cables to ground.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading. (2) Tighten spark plugs to 35-41 N-m (26-30 ft.
lbs.) torque. (3) Install spark plug cables over spark plugs.

8D
- 24
IGNITION
SYSTEMS

•
.040
GAUGE

SPARK

"PLUG

J908D-10
Fig.
16 Setting
Spark Plug
Gap—Typical

SPARK
PLUG
SECONDARY
CABLES
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.

Install cables into
the
proper engine cylinder firing
order (Figs.
17 or 18).

FRONT OF
ENGINE
CLOCKWISE
ROTATION

1-6-5-4-3-2
J9314-80

Fig.
17
Engine
Firing Order—3.9L V-6
Engine

When replacing
the
spark plug
and
coil cables,
route
the
cables correctly
and
secure
in the
proper a

FRONT OF
ENGINE
CLOCKWISE
ROTATION

1-8-4-3-6-5-7-2
J9314-79

Fig.
18
Engine
Firing Order—5.2U5.9L V-8
Engines

retainers. Failure
to
route
the
cables properly
can
cause
the
radio
to
reproduce ignition noise.
It
could
also cause cross ignition
of the
plugs,
or
short circuit
the cables
to
ground.
When installing
new
cables, make sure
a
positive
connection
is
made.
A
snap should
be
felt when
a

good connection
is
made between
the
plug cable
and

the distributor
cap
tower.
Spark plug cable boot heat shields
are
pressed into
the cylinder head
to
surround each cable boot
and
spark plug
(Fig. 19).
These shields protect
the
spark
plug boots from damage
(due to
intense engine heat generated
by the
exhaust manifolds)
and
should
not

be removed. After
the
spark plug cable
has
been
in­
stalled,
the lip of the
cable boot should have
a
small
air
gap to the top of the
heat shield
(Fig. 19).
SPARK
PLUG BOOT

-
HEAT SHIELD
J9314-94

Fig.
19 Heat
Shields

THROTTLE
POSITION
SENSOR
(TPS) For removal
and
installation, refer
to
Throttle
Po­

sition Sensor
in
Group
14,
Fuel Systems.

IGNITION
SYSTEMS
80 - 25

IGNITION
SWITCH

INDEX

General
Information
page
. . 25

GENERAL
INFORMATION
The ignition switch is located in the steering col­
umn. The Key-In-Switch and Halo Light are integral
with the ignition switch. Refer to Group 8M for Key- In-Switch and Halo Light diagnosis.

IGNITION
SWITCH
AND
KEY
CYLINDER
SERVICE

REMOVAL
(1) Disconnect negative battery cable.
(2) Tilt column: Remove tilt lever (counterclock­

wise).

(3) Remove upper and lower shrouds (Fig. 1).
STEERING
WHEEL
NUT
TILT
UPPER
LEVER SHROUD PANEL

BRACKET

SPACER

CLOCK SPRING LOWER
SHROUD NUT
J928J-2

Fig.
1
Shroud
Removal/Installation—Typical (4) Remove ignition switch mounting screws
(Snap-on torx bit tool TTXR20B0 or equivalent re­
quired—Fig. 2).
(5) Gently pull switch away from the column. Re­
lease two connector locks on the 7-terminal wiring
connector. Remove the connector from the ignition switch (Fig. 3).
(6) Release connector lock on the Key-In-Switch
and Halo Light 4-terminal connector (Fig. 3).
(7) Remove the key cylinder from the ignition
switch as follows:
Ignition
Switch
and Key
Cylinder
Service

page

. . 25
STEERING
COLUMN
IGNITION

SWITCH
908D-14

Fig.
2 Ignition
Switch
Screw
Removal
KEY-IN SWITCH &
HALO
LIGHT
MULTIFUNCTION

SWITCH
IGNITION

SWITCH
TURN
SIGNAL
SWITCH & LEVER

SPEED

CONTROL
J918J-2

Fig.
3 Key in
Switch
and Halo
Lamp
Connector

(a) With the key inserted and the ignition switch
in the lock position, proceed as follows: Use a small screwdriver to depress the key cylinder retaining
pin flush with the key cylinder surface (Fig. 4).
(b) Rotate the key clockwise to the OFF position.
The key cylinder should now be unseated from the ignition switch assembly (Fig. 5).

CAUTION:
Do not
remove
key
cylinder
at
this
time.
(c) With key cylinder in unseated position (key
cylinder bezel about 1/8 inch above ignition switch