ECU DODGE RAM 2003 Service Manual PDF

SPECIFICATIONS - TORQUE - STARTING
SYSTEM
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Battery Cable Eyelet Nut at
Solenoid (large nut - gas engines)25 19 221
Battery Cable Eyelet Nut at
Solenoid (large nut - diesel engine)14 - 120
Starter Solenoid Nut (small nut -
diesel engine)6-55
Starter Mounting Bolts - Gas
Engines68 50 -
Starter Mounting Nut - Gas Engines 68 50 -
Starter Mounting Bolts - Diesel 43 32 -
STARTER MOTOR
DIAGNOSIS AND TESTING - STARTER MOTOR
Correct starter motor operation can be confirmed
by performing the following free running bench test.
This test can only be performed with starter motor
removed from vehicle. Refer to Specifications for
starter motor specifications.
(1) Remove starter motor from vehicle. Refer to
Starter Motor Removal and Installation.
(2) Mount starter motor securely in a soft-jawed
bench vise. The vise jaws should be clamped on the
mounting flange of starter motor. Never clamp on
starter motor by field frame.
(3) Connect a suitable volt-ampere tester and a
12-volt battery to starter motor in series, and set
ammeter to 100 ampere scale. See instructions pro-
vided by manufacturer of volt-ampere tester being
used.
(4) Install jumper wire from solenoid terminal to
solenoid battery terminal. The starter motor should
operate. If starter motor fails to operate, replace
faulty starter motor assembly.
(5) Adjust carbon pile load of tester to obtain free
running test voltage. Refer to Specifications for
starter motor free running test voltage specifications.
(6) Note reading on ammeter and compare reading
to free running test maximum amperage draw. Refer
to Specifications for starter motor free running test
maximum amperage draw specifications.
(7) If ammeter reading exceeds maximum amper-
age draw specification, replace faulty starter motor
assembly.
STARTER SOLENOID
This test can only be performed with starter motor
removed from vehicle.(1) Remove starter motor from vehicle. Refer to
Starter Motor Removal and Installation.
(2) Disconnect wire from solenoid field coil termi-
nal.
(3) Check for continuity between solenoid terminal
and solenoid field coil terminal with a continuity
tester (Fig. 7). There should be continuity. If OK, go
to Step 4. If not OK, replace faulty starter motor
assembly.
(4) Check for continuity between solenoid terminal
and solenoid case (Fig. 8). There should be continuity.
If not OK, replace faulty starter motor assembly.
REMOVAL
3.7L / 4.7L
(1) Disconnect and isolate negative battery cable.
(2) Raise and support vehicle.
(3) Note: If equipped with 4WD and certain trans-
missions, a support bracket is used between front
axle and side of transmission. Remove 2 support
bracket bolts at transmission. Pry support bracket
slightly to gain access to lower starter mounting bolt.
Fig. 7 CONTINUITY BETWEEN SOLENOID AND
FIELD COIL TERMINALS - TYPICAL
1 - OHMMETER
2 - SOLENOID TERMINAL
3 - FIELD COIL TERMINAL
8F - 34 STARTINGDR
STARTING (Continued)

(4) Remove 1 bolt and 1 nut if equipped with a
manual transmission (Fig. 9).
(5) Remove 2 bolts if equipped with an automatic
transmission (Fig. 10).
(6) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
housing. Always support starter motor during this
process, do not let starter motor hang from wire har-
ness.
(7) Tilt nose downwards and lower starter motor
far enough to access and remove nut that secures
battery positive cable wire harness connector eyelet
to solenoid battery terminal stud. Do not let starter
motor hang from wire harness.
(8) Remove battery positive cable wire harness
connector eyelet from solenoid battery terminal stud.
(9) Disconnect battery positive cable wire harness
connector from solenoid terminal connector recepta-
cle.
(10) Remove starter motor.
5.7L Gas
(1) Disconnect and isolate negative battery cable.
(2) Raise and support vehicle.
(3) Note: If equipped with 4WD and certain trans-
missions, a support bracket is used between front
axle and side of transmission. Remove 2 support
bracket bolts at transmission. Pry support bracket
slightly to gain access to lower starter mounting bolt.
(4) Remove 2 mounting bolts (Fig. 11).
(5) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
housing. Always support starter motor during this
process, do not let starter motor hang from wire har-
ness.
(6) Tilt nose downwards and lower starter motor
far enough to access and remove nut that secures
battery positive cable wire harness connector eyelet
to solenoid battery terminal stud. Do not let starter
motor hang from wire harness.
(7) Remove battery positive cable wire harness
connector eyelet from solenoid battery terminal stud.(8) Disconnect battery positive cable wire harness
connector from solenoid terminal connector recepta-
cle.
(9) Remove starter motor.
5.9L Diesel
(1) Disconnect and isolate both negative battery
cables at both batteries.
(2) Raise and support vehicle.
(3) Remove 3 starter mounting bolts (Fig. 12).
Fig. 8 CONTINUITY BETWEEN SOLENOID
TERMINAL AND CASE - TYPICAL
1 - SOLENOID TERMINAL
2 - OHMMETER
3 - SOLENOID
Fig. 9 STARTER R/I - 3.7L/4.7L - MAN. TRANS.
1 - EYELET TERMINAL
2 - NUT
3 - BRACKET
4 - STUD
5 - STARTER MOTOR
6 - LOCK WASHER
7 - WIRE HARNESS CONNECTOR
8 - NUT
9 - SCREW AND WASHER (2)
Fig. 10 STARTER R/I - 3.7L/4.7L - AUTO. TRANS.
1 - EYELET TERMINAL
2 - NUT
3 - SCREW AND WASHER (2)
4 - STARTER MOTOR
5 - WIRE HARNESS CONNECTOR
DRSTARTING 8F - 35
STARTER MOTOR (Continued)

(4) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
housing. Always support starter motor during this
process. Do not let starter motor hang from wire har-
ness.
(5) Tilt nose downwards and lower starter motor
far enough to access and remove nuts securing
starter wiring harness to starter (Fig. 13). Do not let
starter motor hang from wire harness.
(6) Remove starter motor from engine. Note: Cer-
tain diesel engines use an aluminum spacer (Fig. 12).
Note position and orientation of spacer before
removal.
5.9L Gas
(1) Disconnect and isolate negative battery cable.
(2) Raise and support vehicle.
(3) Note: If equipped with 4WD and certain trans-
missions, a support bracket is used between front
axle and side of transmission. Remove 2 support
bracket bolts at transmission. Pry support bracket
slightly to gain access to lower starter mounting bolt.
(4) Remove nut and lock washer securing starter
motor to mounting stud (Fig. 14).
(5) While supporting starter motor, remove upper
mounting bolt from starter motor.
(6) If equipped with automatic transmission, slide
cooler tube bracket forward on tubes far enough for
starter motor mounting flange to be removed from
lower mounting stud.
(7) Move starter motor towards front of vehicle far
enough for nose of starter pinion housing to clear
Fig. 11 STARTER R/I - 5.7L
1 - STARTER MOTOR
2 - MOUNTING BOLTS
Fig. 12 STARTER R/I - 5.9L DIESEL
1 - MOUNTING BOLTS (3)
2 - STARTER MOTOR
3 - SPACER (CERTAIN TRANSMISSIONS)
Fig. 13 STARTER ELECTRICAL CONNECTORS -
5.9L DIESEL
1 - STARTER MOTOR
2 - BATTERY CABLE NUT
3 - SOLENOID NUT
4 - HARNESS ASSEMBLY
8F - 36 STARTINGDR
STARTER MOTOR (Continued)

housing. Always support starter motor during this
process, do not let starter motor hang from wire har-
ness.
(8) Tilt nose downwards and lower starter motor
far enough to access and remove nut that secures
battery positive cable wire harness connector eyelet
to solenoid battery terminal stud. Do not let starter
motor hang from wire harness.
(9) Remove battery positive cable wire harness
connector eyelet from solenoid battery terminal stud.
(10) Disconnect battery positive cable wire harness
connector from solenoid terminal connector recepta-
cle.
(11) Remove starter motor.
INSTALLATION
3.7L / 4.7L
(1) Connect solenoid wire to starter motor (snaps
on).
(2) Position battery cable to solenoid stud. Install
and tighten battery cable eyelet nut. Refer to Torque
Specifications. Do not allow starter motor to hang
from wire harness.
(3) Position starter motor to transmission.
(4) If equipped with automatic transmission, slide
cooler tube bracket into position.(5) Install and tighten both bolts (auto. trans.), or
1 nut and 1 bolt (man. trans.). Refer to Torque Spec-
ifications.
(6) Lower vehicle.
(7) Connect negative battery cable.
5.7L
(1) Connect solenoid wire to starter motor (snaps
on).
(2) Position battery cable to solenoid stud. Install
and tighten battery cable eyelet nut. Refer to Torque
Specifications. Do not allow starter motor to hang
from wire harness.
(3) Position starter motor to engine.
(4) If equipped with automatic transmission, slide
cooler tube bracket into position.
(5) Install and tighten both mounting bolts. Refer
to Torque Specifications.
(6) Lower vehicle.
(7) Connect negative battery cable.
5.9L Diesel
(1)If Equipped:Position and hold aluminum
spacer to rear of starter while positioning starter to
engine.
(2) Connect solenoid wire to starter motor. Tighten
nut.
(3) Position battery cable to starter stud. Install
and tighten battery cable nut. Refer to Torque Spec-
ifications. Do not allow starter motor to hang from
wire harness.
(4) Position starter motor to transmission.
(5) If equipped with automatic transmission, slide
cooler tube bracket into position.
(6) Install and tighten 3 starter mounting bolts.
Refer to Torque Specifications.
(7) Lower vehicle.
(8) Connect both negative battery cables to both
batteries.
5.9L Gas
(1) Connect solenoid wire to starter motor (snaps
on).
(2) Position battery cable to solenoid stud. Install
and tighten battery cable eyelet nut. Refer to Torque
Specifications. Do not allow starter motor to hang
from wire harness.
(3) Position starter motor to transmission.
(4) If equipped with automatic transmission, slide
cooler tube bracket into position.
(5) Install and tighten both bolts (auto. trans.), or
1 nut and 1 bolt (man. trans.). Refer to Torque Spec-
ifications.
(6) Lower vehicle.
(7) Connect negative battery cable.
Fig. 14 STARTER R/I - 5.9L GAS
1 - ENGINE
2 - STARTER MOUNTING FLANGE
3 - STUD
4 - STARTER MOTOR
5 - LOCK WASHER
6 - NUT
7 - BRACKET
8 - BOLT
9 - POSITIVE BATTERY CABLE WIRE HARNESS
10 - POSITIVE BATTERY CABLE WIRE HARNESS NUT
DRSTARTING 8F - 37
STARTER MOTOR (Continued)

heated mirror switch is depressed and released a sec-
ond time during the same ignition cycle, the elec-
tronic control logic and timer circuitry will
automatically turn the heated mirror system off after
a programmed time interval of about five minutes.
The heated mirror system will be shut off automati-
cally if the ignition switch is turned to the Off or
Accessory positions. After the heated mirror system
is turned On, it can also be turned off manually by
depressing and releasing the heated mirror switch a
second time.
When the heated mirror system is turned On, the
heated mirror system control logic and timer cir-
cuitry energizes the heated mirror system indicator
lamp and the heated mirror relay. When energized,
the heated mirror relay supplies fused ignition
switch output (run/start) current from a fuse in the
JB to the outside mirror heating grids located behind
the mirror glass of each of the outside rear view mir-
rors. When energized, each of the outside mirror
heating grids produces enough heat to warm the
glass of the outside rear view mirrors.
DIAGNOSIS AND TESTING - HEATED MIRROR
SYSTEM
If only one of the outside mirror heating grids is
inoperative, perform continuity checks on the circuits
and heater grid for that mirror only. If both outside
mirror heating grids are inoperative, proceed with
the heated mirror system diagnosis as follows. (Refer
to Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.The operation of the heated mirror system can be
confirmed in one of the following manners:
1. Turn the ignition switch to the On position.
While monitoring the instrument panel voltmeter,
momentarily depress and release the heated mirror
switch. When the heated mirror system is turned On,
a distinct voltmeter needle deflection should be
noted.
2. Turn the ignition switch to the On position.
Momentarily depress and release the heated mirror
switch to turn the heated mirror system On. The
heated mirror operation can be checked by feeling
the outside rear view mirror glass. A distinct differ-
ence in temperature between the unheated and
heated mirror glass can be detected within three to
four minutes of system operation.
The above checks will confirm system operation.
Illumination of the heated mirror system indicator
lamp means that there is electrical current available
at the heated mirror relay, but does not confirm that
the electrical current is reaching the outside mirror
heating grids.
If the heated mirror system does not operate, the
problem should be isolated in the following manner:
(1) Confirm that the ignition switch is in the On
position.
(2) Check the fuses in the Power Distribution Cen-
ter (PDC) and in the Junction Block (JB). The fuses
must be tight in their receptacles and all electrical
connections must be secure.
When the above steps have been completed and
both outside mirror heating grids are still inopera-
tive, one or more of the following is faulty:
²Heated mirror switch, electronic control logic
and timer circuitry, and heated mirror relay.
²Heated mirror wire harness circuits or connec-
tors.
²Outside mirror heating grid (both mirror grids
would have to be faulty).
If turning On the heated mirror system produces a
severe voltmeter deflection or fuse failures, check for
a shorted circuit between the output of the heated
mirror relay and the outside mirror heating grids.
8G - 2 HEATED MIRRORSDR
HEATED MIRRORS (Continued)

diagnostic feedback for the heated seat system. Each
switch also has an incandescent bulb, which provides
dimmer controlled back lighting of the switch when
the headlamps or park lamps are on.
The heated seat switches are both mounted in the
instrument panel center bezel, located in the lower
center of the instrument panel. The two switches are
snapped into the mounting holes of the heated seat
switch bezel, and the heated seat switch bezel is
secured with screws to the instrument panel center
bezel. The heated seat switches are differentiated by
the keyway in the connector receptacle on the backs
of the switches and keyway on the switch housing.
The instrument panel wire harness connectors for
the heated seat switches are keyed to match the con-
nector receptacles on the switches so that the two
heated seat switches can only be connected to the
proper heated seat electrical.
The two LED indicator lamps and the incandescent
bulb in each heated seat switch cannot be repaired. If
the indicator lamps or back lighting bulb are faulty
or damaged, the individual heated seat switch must
be replaced.
OPERATION
The heated seat switches receive battery current
through a fused ignition switch output (run) circuit
when the ignition switch is in the On position.
Depressing the heated seat switch rocker to its
momentary High or Low position provides a hard-wired resistance signal to the heated seat module.
This signal tells the module to energize the heated
seat element of the selected seat and maintain the
requested temperature setting. If the heated seat
switch is depressed to a different position (Low or
High) than the currently selected state, the heated
seat module will change states to support the new
selection. If a heated seat switch is depressed a sec-
ond time, the heated seat module interprets the sec-
ond input as a request to turn the seat heater OFF.
The High and Low LED indicator lamps in the
heated seat switches receive battery current through
a fused ignition switch output (run) circuit when the
ignition switch is in the On position. The ground side
of each indicator lamp is controlled by the heated
seat module. This control of the switch indicator
lamps also allows the module to provide diagnostic
feedback to the vehicle operator or technician to indi-
cate heated seat system faults by flashing the indica-
tor lamps on and off. One side of the incandescent
back lighting bulb in each heated seat switch is con-
nected to ground at all times. The other side of the
incandescent bulb is connected to the fused panel
lamps dimmer switch signal circuit. These bulbs are
energized when the park lamps or headlamps are
turned on, and their illumination intensity is con-
trolled by the panel lamps dimmer switch.
DIAGNOSIS AND TESTING - HEATED SEAT
SWITCH
Refer toWiring Diagramsfor connector pin-outs
and the location of complete heated seat system wir-
ing diagrams.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
(1) If the problem being diagnosed involves inoper-
ative heated seat switch back lighting and the cluster
illumination lamps operate, go to Step 2. If the prob-
lem being diagnosed involves inoperative heated seat
switch back lighting and the cluster illumination
lamps are also inoperative, (Refer to 8 - ELECTRI-
CAL/INSTRUMENT CLUSTER - DIAGNOSIS AND
TESTING). If the problem being diagnosed involves
Fig. 4 HEATED SEAT SWITCH
1 - HEATED SEAT SWITCH
2 - LIGHT-EMITTING DIODE (LED) INDICATOR LAMPS
8G - 8 HEATED SEAT SYSTEMDR
HEATED SEAT SWITCH (Continued)

inoperative heated seat switch indicator lamps and
the heated seat elements do not heat, proceed. If the
problem being diagnosed involves inoperative heated
seat switch indicator lamps and the heated seat ele-
ments do heat, go to Step 6. If the problem being
diagnosed involves a heated seat switch indicator
lamp that remains illuminated after the heated seat
has been turned Off, (Refer to 8 - ELECTRICAL/
ELECTRONIC CONTROL MODULES/MEMORY
HEATED SEAT/MIRROR MODULE - DIAGNOSIS
AND TESTING).
(2) Disconnect and isolate the battery negative
cable. Remove the heated seat switch and bezel unit
from the instrument panel. Disconnect the heated
seat switch to be tested. Check for continuity
between the ground circuit cavity of the heated seat
switch and a good ground. There should be continu-
ity. If OK, go to Step 3. If not OK, repair the open
ground circuit to ground as required.
(3) Reconnect the battery negative cable. Turn the
park lamps on with the headlamp switch. Rotate the
panel lamps dimmer thumb wheel on the headlamp
switch upward to just before the interior lamps
detent. Check for battery voltage at the fused panel
lamps dimmer circuit cavity of the heated seat
switch. If OK, go to Step 4. If not OK, repair the
open fused panel lamps dimmer switch signal circuit
to the fuse in the Integrated Power Module as
required.
(4) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (run) circuit cavity of the heated seat switch.
If OK, go to Step 5. If not OK, repair the open fused
ignition switch output (run) circuit as required.
(5) Check the continuity and resistance values of
the heated seat switch in the Neutral, Low and High
positions as shown in the Heated Seat Switch Conti-
nuity chart. If OK, refer to Step 6. If not OK, replace
the faulty heated seat switch.
HEATED SEAT SWITCH CONTINUITY
Switch PositionContinuity
BetweenResistance
Neutral 4 & 6 2.2 Kilohms
Low 4 & 6 .415 Kilohms
High 4 & 6 33 Ohms(6) Replace the inoperative heated seat switch
with a known good unit and test the operation of the
switch indicator lamps. If OK, discard the faulty
heated seat switch. If not OK, (Refer to 8 - ELEC-
TRICAL/ELECTRONIC CONTROL MODULES/
MEMORY HEATED SEAT/MIRROR MODULE -
DIAGNOSIS AND TESTING).
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Wait two minutes for the system reserve capac-
itor to discharge before beginning any airbag or
instrument panel service.
(3) Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - REMOV-
AL).
(4) Remove the screws that secure the heated seat
switch bezel to the instrument panel center bezel.
(5) Remove the heated seat switch bezel and both
switches from the instrument panel as a unit.
(6) From the back of the heated seat switch bezel,
gently pry the switch free and push the heated seat
switch out through the front of the bezel.
INSTALLATION
NOTE: When installing the heated seat switches, be
certain they are installed in the proper mounting
holes of the heated seat switch bezel. The heated
seat switches are differentiated by the keyway in
the connector receptacle on the backs of the
switches and keyway on the switch housing (Fig.
4).
(1) From the back of the heated seat switch bezel,
gently push the heated seat switch in through the
front of the bezel.
(2) Position the heated seat switch bezel to the
instrument panel center bezel and install the retain-
ing screws.
(3) Install the center bezel on the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL - INSTAL-
LATION).
(4) Connect the battery negative cable.
(5) Verify vehicle and system operation.
DRHEATED SEAT SYSTEM 8G - 9
HEATED SEAT SWITCH (Continued)

The PCM adjusts ignition timing based on inputs it
receives from:
²The engine coolant temperature sensor
²The crankshaft position sensor (engine speed)
²The camshaft position sensor (crankshaft posi-
tion)
²The manifold absolute pressure (MAP) sensor
²The throttle position sensor
²Transmission gear selection
REMOVAL
3.7L V-6
An individual ignition coil is used for each spark
plug (Fig. 30). The coil fits into machined holes in the
cylinder head. A mounting stud/nut secures each coil
to the top of the intake manifold (Fig. 31). The bot-
tom of the coil is equipped with a rubber boot to seal
the spark plug to the coil. Inside each rubber boot is
a spring. The spring is used for a mechanical contact
between the coil and the top of the spark plug. These
rubber boots and springs are a permanent part of the
coil and are not serviced separately. An o-ring (Fig.
30) is used to seal the coil at the opening into the cyl-
inder head.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coil.
(2) Disconnect electrical connector from coil by
pushing downward on release lock on top of connec-
tor and pull connector from coil.
(3) Clean area at base of coil with compressed air
before removal.
(4) Remove coil mounting nut from mounting stud
(Fig. 31).
(5) Carefully pull up coil from cylinder head open-
ing with a slight twisting action.
(6) Remove coil from vehicle.
4.7L V-8
An individual ignition coil is used for each spark
plug (Fig. 30). The coil fits into machined holes in the
cylinder head. A mounting stud/nut secures each coil
to the top of the intake manifold (Fig. 32). The bot-
tom of the coil is equipped with a rubber boot to seal
the spark plug to the coil. Inside each rubber boot is
a spring. The spring is used for a mechanical contact
between the coil and the top of the spark plug. These
rubber boots and springs are a permanent part of the
coil and are not serviced separately. An o-ring (Fig.
30) is used to seal the coil at the opening into the cyl-
inder head.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coil.(2) Disconnect electrical connector (Fig. 32) from
coil by pushing downward on release lock on top of
connector and pull connector from coil.
(3) Clean area at base of coil with compressed air
before removal.
(4) Remove coil mounting nut from mounting stud
(Fig. 32).
(5) Carefully pull up coil from cylinder head open-
ing with a slight twisting action.
(6) Remove coil from vehicle.
5.7L V-8
Before removing or disconnecting any spark plug
cables, note their original position. Remove cables
one-at-a-time. To prevent ignition crossfire, spark
plug cablesMUSTbe placed in cable tray (routing
loom) into their original position.
An individual ignition coil (Fig. 33) is used at each
cylinder. The coil mounts to the top of the valve cover
with 2 bolts (Fig. 34). The bottom of the coil is
equipped with a rubber boot to seal the spark plug to
the coil. Inside each rubber boot is a spring. The
spring is used for a mechanical contact between the
coil and the top of the spark plug.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coil.
(2) Unlock electrical connector (Fig. 34) by moving
slide lock first. Press on release lock (Fig. 34) while
pulling electrical connector from coil.
(3) Disconnect secondary high-voltage cable from
coil with a twisting action.
(4) Clean area at base of coil with compressed air
before removal.
(5) Remove 2 mounting bolts (note that mounting
bolts are retained to coil).
(6) Carefully pull up coil from cylinder head open-
ing with a slight twisting action.
(7) Remove coil from vehicle.
(8) Before installing spark plug cables to either the
spark plugs or coils, or before installing a coil to a
spark plug, apply dielectric grease to inside of boots.
5.9L V-8
The coil is not oil filled. The coil windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the coil to be
mounted on the engine. If the coil is replaced, it must
be replaced with the same type.
5.9L V-8 LDC-Gas Engines: The coil is mounted to
a bracket that is bolted to the front of the right
engine cylinder head (Fig. 35). This bracket is
mounted on top of the automatic belt tensioner
bracket using common bolts.
DRIGNITION CONTROL 8I - 23
IGNITION COIL (Continued)

WARNING: 5.9L V-8 LDC-GAS ENGINES: DO NOT
REMOVE THE COIL MOUNTING BRACKET-TO-CYL-
INDER 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.
5.9L V-8 HDC-Gas Engine: The coil is mounted to
a bracket that is bolted to the air injection pump
(AIR pump) mounting bracket (Fig. 36).
(1) Disconnect primary coil connector from ignition
coil.
(2) Disconnect secondary cable from ignition coil.
(3) Remove ignition coil from coil mounting
bracket (two bolts).
8.0L V-10
Two separate coil packs containing a total of five
independent coils are attached to a common mount-
ing bracket located above the right engine valve
cover (Fig. 37). The front and rear coil packs can be
serviced separately.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coils.
(2) Remove secondary spark plug cables from coil
packs. Note position of cables before removal.
(3) Disconnect primary wiring harness connectors
at coil packs.
(4) Remove four (4) coil pack-to-coil mounting
bracket bolts for coil pack being serviced (Fig. 37).
(5) Remove coil(s) from mounting bracket.
INSTALLATION
3.7L V-6
(1) Using compressed air, blow out any dirt or con-
taminants from around top of spark plug.
(2) Check condition of coil o-ring and replace as
necessary. To aid in coil installation, apply silicone to
coil o-ring.
(3) Position ignition coil into cylinder head opening
and push onto spark plug. Do this while guiding coil
base over mounting stud.
(4) Install coil mounting stud nut. Refer to torque
specifications.
(5) Connect electrical connector to coil by snapping
into position.
(6) If necessary, install throttle body air tube.
4.7L V-8
(1) Using compressed air, blow out any dirt or con-
taminants from around top of spark plug.
(2) Check condition of coil o-ring and replace as
necessary. To aid in coil installation, apply silicone to
coil o-ring.
(3) Position ignition coil into cylinder head opening
and push onto spark plug. Do this while guiding coil
base over mounting stud.
(4) Install coil mounting stud nut. Refer to torque
specifications.
(5) Connect electrical connector to coil by snapping
into position.
(6) If necessary, install throttle body air tube.
5.7L V-8
(1) Using compressed air, blow out any dirt or con-
taminants from around top of spark plug.
(2) Before installing spark plug cables to either the
spark plugs or coils, or before installing a coil to a
spark plug, apply dielectric grease to inside of boots.
(3) Position ignition coil into cylinder head opening
and push onto spark plug. Twist coil into position.
(4) Install 2 coil mounting bolts. Refer to torque
specifications.
(5) Connect electrical connector to coil by snapping
into position.
(6) Install cable to coil. To prevent ignition cross-
fire, spark plug cablesMUSTbe placed in cable tray
(routing loom) into their original position. Refer to
Spark Plug Cable Removal for a graphic.
(7) If necessary, install throttle body air tube.
5.9L V-8
The ignition coil is an epoxy filled type. If the coil
is replaced, it must be replaced with the same type.
(1) Install 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 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.
8.0L V-10
(1) Position coil packs to mounting bracket (prima-
ry wiring connectors face downward).
(2) Install coil pack mounting bolts. Tighten bolts
to 10 N´m (90 in. lbs.) torque.
(3) Install coil pack-to-engine mounting bracket (if
necessary).
(4) Connect primary wiring connectors to coil
packs (four wire connector to front coil pack and
three wire connector to rear coil pack).
(5) Connect secondary spark plug cables to coil
packs. Refer to (Fig. 38) for correct cable order.
8I - 24 IGNITION CONTROLDR
IGNITION COIL (Continued)

4.7L V-8
CAUTION: The 4.7L V±8 engine is equipped with
copper core ground electrode spark plugs. They
must be replaced with the same type/number spark
plug as the original. If another spark plug is substi-
tuted, pre-ignition will result.
Special care should be taken when installing spark
plugs into the cylinder head spark plug wells. Be
sure the plugs do not drop into the plug wells as elec-
trodes can be damaged.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap or a cracked porcelain
insulator.
(1) Start the spark plug into the cylinder head by
hand to avoid cross threading.
(2) Tighten spark plugs. Refer to torque specifica-
tions.
(3) Before installing ignition coil(s), check condi-
tion of coil o-ring and replace as necessary. To aid in
coil installation, apply silicone to coil o-ring.
(4) Install ignition coil(s). Refer to Ignition Coil
Removal/Installation.
5.7L V-8
(1) Special care should be taken when installing
spark plugs into the cylinder head spark plug wells.
Be sure the plugs do not drop into the plug wells as
electrodes can be damaged.
(2) Start the spark plug into cylinder head by
hand to avoid cross threading aluminum threads. To
aid in installation, attach a piece of rubber hose, or
an old spark plug boot to spark plug.
(3) The 5.7L V-8 is equipped with torque critical
design spark plugs. Do not exceed 15 ft. lbs. torque.
Tighten spark plugs. Refer to torque specifications.
(4) Before installing spark plug cables to either the
spark plugs or coils, apply dielectric grease to inside
of boots.
(5) To prevent ignition crossfire, spark plug cables
MUSTbe placed in cable tray (routing loom) into
their original position. Refer to Spark Plug Cable
Removal for a graphic.
(6) Install ignition coil(s) to necessary spark plugs.
Refer to Ignition Coil Installation.
(7) Install spark plug cables to remaining spark
plugs. Remember to apply dielectric grease to inside
of boots.
5.9L V-8
Special care should be taken when installing spark
plugs into the cylinder head spark plug wells. Be
sure the plugs do not drop into the plug wells as elec-
trodes can be damaged.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap or a cracked porcelain
insulator.
When replacing the spark plug and ignition coil
cables, 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. Refer to torque specifica-
tions.
(3) Install spark plug cables to spark plugs. On
5.9L V-8 engines, spark plug cable heat shields are
pressed into the cylinder head to surround each
spark plug cable boot and spark plug (Fig. 53). 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 installed, the lip of the
cable boot should have a small air gap to the top of
the heat shield (Fig. 53).
8.0L V-10
Special care should be taken when installing spark
plugs into the cylinder head spark plug wells. Be
sure the plugs do not drop into the plug wells as elec-
trodes can be damaged.
Always tighten spark plugs to the specified torque.
Over tightening can cause distortion resulting in a
change in the spark plug gap or a cracked porcelain
insulator.
When replacing the spark plug and ignition coil
cables, 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. Refer to torque specifica-
tions.
(3) Install spark plug cables to spark plugs.
8I - 32 IGNITION CONTROLDR
SPARK PLUG (Continued)