Wiring harness DODGE RAM 2003 Service Owner's Guide

WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the wire harness connectors from
the horns (Fig. 1).
(3) Remove mounting bolt and remove horns.
INSTALLATION
(1) Position horns and install mounting bolt.
Tighten the bolt to 10 N´m (85 in. lbs.).
(2) Connect wire harness connectors.
(3) Connect battery negative cable.
HORN SWITCH
DESCRIPTION
The horn switch is molded into the driver airbag.
The horn switch can not be serviced separately. For
service procedures, (Refer to 8 - ELECTRICAL/RE-
STRAINTS/DRIVER AIRBAG - REMOVAL).
DIAGNOSIS AND TESTING - HORN SWITCH
The most reliable, efficient, and accurate
means to diagnose the horn system requires the
use of a DRBIIItscan tool and the proper Diag-
nostic Procedures manual. The DRBIIItscan
tool can provide confirmation that the PCI data
bus is functional, that all of the electronic mod-
ules are sending and receiving the proper mes-
sages on the PCI data bus, and that the horns
are being sent the proper hard wired outputs
for them to perform their functions.
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, SEAT BELT TENSIONER, SIDE
AIRBAG, 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.
Fig. 1 HORN
1 - WIRE HARNESS CONNECTORS
2 - HORNS
3 - MOUNTING BOLT
8H - 2 HORNDR
HORN (Continued)

(4) Disconnect camshaft position sensor wiring
harness from main engine wiring harness.
(5) Remove distributor rotor from distributor shaft.
(6) Lift camshaft position sensor assembly from
distributor housing (Fig. 17).
8.0L V±10
The camshaft position sensor is located on the tim-
ing chain case/cover on the left-front side of the
engine (Fig. 18).
A thin plastic rib is molded into the face of the sen-
sor (Fig. 19) to position the depth of sensor to the
upper cam gear (sprocket). This rib can be found on
both the new replacement sensors and sensors that
were originally installed to the engine. The first timethe engine has been operated, part of this rib may be
sheared (ground) off. Depending on parts tolerances,
some of the rib material may still be observed after
removal.
Refer to either of the following procedures; Replac-
ing Old Sensor With Original, or Replacing With
New Sensor:
REPLACING OLD SENSOR WITH ORIGINAL
If the original camshaft position sensor is to be
removed and installed, such as when servicing the
timing chain, timing gears or timing chain cover, use
this procedure.
(1) Disconnect sensor harness connector from sen-
sor.
(2) Remove sensor mounting bolt (Fig. 18).
(3) Carefully pry sensor from timing chain case/
cover in a rocking action with two small screwdriv-
ers.
(4) Remove sensor from vehicle.
(5) Check condition of sensor o-ring (Fig. 20).
REPLACING WITH NEW SENSOR
If a new replacement camshaft position sensor is to
be installed, use this procedure.
(1) Disconnect sensor wiring harness connector
from sensor.
(2) Remove sensor mounting bolt (Fig. 18).
(3) Carefully pry sensor from timing chain case/
cover in a rocking action with two small screwdriv-
ers.
(4) Remove sensor from vehicle.
Fig. 17 DISTRIBUTOR AND CMP LOCATION - 5.9L
1 - SYNC SIGNAL GENERATOR
2 - CAMSHAFT POSITION SENSOR
3 - PULSE RING
4 - DISTRIBUTOR ASSEMBLY
Fig. 18 CMP LOCATION - 8.0L
1 - CAMSHAFT POSITION SENSOR
2 - MOUNTING BOLT
3 - TIMING CHAIN CASE/COVER
Fig. 19 SENSOR DEPTH POSITIONING RIB ± 8.0L
V-10 ENGINE
1 - CAMSHAFT POSITION SENSOR
2 - PAPER SPACER
3 - RIB MATERIAL (FOR SENSOR DEPTH POSITIONING)
DRIGNITION CONTROL 8I - 13
CAMSHAFT POSITION SENSOR (Continued)

INSTALLATION
3.7L V-6
The Camshaft Position Sensor (CMP) on the 3.7L
V-6 engine is bolted to the front/top of the right cyl-
inder head (Fig. 12).
(1) Clean out machined hole in cylinder head.
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into cylinder head with a slight
rocking and twisting action.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to cylinder head.
If sensor is not flush, damage to sensor mounting
tang may result.
(4) Install mounting bolt and tighten. Refer to
torque specifications.
(5) Connect electrical connector to sensor.
4.7L V-8
The Camshaft Position Sensor (CMP) on the 4.7L
V-8 engine is bolted to the front/top of the right cyl-
inder head (Fig. 13).
(1) Clean out machined hole in cylinder head.
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into cylinder head with a slight
rocking action. Do not twist sensor into position as
damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to cylinder head.
If sensor is not flush, damage to sensor mounting
tang may result.(4) Install mounting bolt and tighten. Refer to
Torque Specifications.
(5) Connect electrical connector to sensor.
5.7L V-8
The Camshaft Position Sensor (CMP) on the 5.7L
V-8 engine is bolted to the right / front side of the
timing chain cover (Fig. 14) or (Fig. 15).
(1) Clean out machined hole in cylinder head.
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into cylinder head with a slight
rocking action. Do not twist sensor into position as
damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to timing chain
cover. If sensor is not flush, damage to sensor
mounting tang may result.
(4) Install mounting bolt and tighten. Refer to
Torque Specifications.
(5) Connect electrical connector to sensor.
5.9L Diesel
The CMP is located on the back of the timing gear
cover (Fig. 16).
(1) Clean out machined hole in back of timing gear
cover.
(2) Apply a small amount of engine oil to sensor
o-ring.
(3) Install sensor into timing gear cover with a
slight rocking action. Do not twist sensor into posi-
tion as damage to o-ring may result.
CAUTION: Before tightening sensor mounting bolt,
be sure sensor is completely flush to back of timing
chain cover. If sensor is not flush, damage to sen-
sor mounting tang may result.
(4) Install mounting bolt and tighten. Refer to
Torque Specifications.
(5) Connect electrical connector to sensor.
5.9L Gas
The camshaft position sensor is located inside the
distributor (Fig. 17).
(1) Install camshaft position sensor to distributor.
Align sensor into notch on distributor housing.
(2) Connect engine wiring harness to sensor pigtail
harness.
(3) Install rotor.
(4) Install distributor cap. Tighten 2 mounting
screws.
(5) Install air filter tubing.
(6) Connect battery cable.
Fig. 20 CAMSHAFT SENSOR O-RING ± 8.0L
1 - SLOTTED MOUNTING HOLE
2 - SCRIBE LINE
3 - CAMSHAFT POSITION SENSOR O-RING
8I - 14 IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)

8.0L V±10
If Replacing Old Sensor With Original
The camshaft position sensor is located on the tim-
ing chain case/cover on the left-front side of the
engine (Fig. 18).
When installing a used camshaft position sensor,
the sensor depth must be adjusted to prevent contact
with the camshaft gear (sprocket).
(1) Observe the face of the sensor. If any of the
original rib material remains (Fig. 19), it must be cut
down flush to the face of the sensor with a razor
knife. Remove only enough of the rib material until
the face of the sensor is flat. Do not remove more
material than necessary as damage to sensor may
result. Due to a high magnetic field and possible elec-
trical damage to the sensor, never use an electric
grinder to remove material from sensor.
(2) From the parts department, obtain a peel-and-
stick paper spacer (Fig. 19). These special paper
spacers are of a certain thickness and are to be used
as a tool to set sensor depth.
(3) Clean the face of sensor and apply paper
spacer (Fig. 19).
(4) Apply a small amount of engine oil to the sen-
sor o-ring (Fig. 20).
A low and high area are machined into the cam-
shaft drive gear (Fig. 21). The sensor is positioned in
the timing gear cover so that a small air gap (Fig.
21) exists between the face of sensor and the high
machined area of cam gear.
Before the sensor is installed, the cam gear may
have to be rotated. This is to allow the high
machined area on the gear to be directly in front of
the sensor mounting hole opening on the timing gear
cover.
Do not install sensor with gear positioned at
low area (Fig. 22) or (Fig. 21). When the engine
is started, the sensor will be broken.
(5) Using a 1/2 in. wide metal ruler, measure the
distance from the cam gear to the face of the sensor
mounting hole opening on the timing gear cover (Fig.
22).
(6) If the dimension is approximately 1.818 inches,
it is OK to install sensor. Proceed to step Step 9.
(7) If the dimension is approximately 2.018 inches,
the cam gear will have to be rotated.
(8) Attach a socket to the vibration damper mount-
ing bolt and rotate engine until the 1.818 inch
dimension is attained.
(9) Install the sensor into the timing case/cover
with a slight rocking action until the paper spacer
contacts the camshaft gear. Do not install the sensor
mounting bolt. Do not twist the sensor into position
as damage to the o-ring or tearing of the paper
spacer may result.(10) Scratch a scribe line into the timing chain
case/cover to indicate depth of sensor (Fig. 20).
(11) Remove the sensor from timing chain case/
cover.
(12) Remove paper spacer from sensor. This step
must be followed to prevent the paper spacer from
getting into the engine lubrication system.
(13) Again, apply a small amount of engine oil to
sensor o-ring.
(14) Again, install the sensor into the timing case/
cover with a slight rocking action until the sensor is
aligned to scribe line.
(15) Install sensor mounting bolt and tighten to 6
N´m (50 in. lbs.) torque.
(16) Connect engine wiring harness to sensor.
Replacing With a New Sensor
(1) Apply a small amount of engine oil to the sen-
sor o-ring (Fig. 20).
A low and high area are machined into the cam-
shaft drive gear (Fig. 21). The sensor is positioned in
the timing gear cover so that a small air gap (Fig.
21) exists between the face of sensor and the high
machined area of cam gear.
Before the sensor is installed, the cam gear may
have to be rotated. This is to allow the high
machined area on the gear to be directly in front of
the sensor mounting hole opening on the timing gear
cover.
Fig. 21 SENSOR OPERATION ± 8.0L V-10 ENGINE
1 - CAM DRIVE GEAR
2 - LOW MACHINED AREA
3 - HIGH MACHINED AREA
4 - CAMSHAFT POSITION SENSOR
5 - AIR GAP
DRIGNITION CONTROL 8I - 15
CAMSHAFT POSITION SENSOR (Continued)

Do not install sensor with gear positioned at
low area (Fig. 22) or (Fig. 21). When the engine
is started, the sensor will be broken.
(2) Using a 1/2 in. wide metal ruler, measure the
distance from the cam gear to the face of the sensor
mounting hole opening on the timing gear cover (Fig.
22).
(3) If the dimension is approximately 1.818 inches,
it is OK to install sensor. Proceed to step Step 9.
(4) If the dimension is approximately 2.018 inches,
the cam gear will have to be rotated.
(5) Attach a socket to the vibration damper mount-
ing bolt and rotate engine until the 1.818 inch
dimension is attained.
(6) Install the sensor into the timing case/cover
with a slight rocking action. Do not twist the sensor
into position as damage to the o-ring may result.
Push the sensor all the way into the cover until the
rib material on the sensor (Fig. 19) contacts the cam-
shaft gear.
(7) Install the mounting bolt and tighten to 6 N´m
(50 in. lbs.) torque.
(8) Connect sensor wiring harness to engine har-
ness.When the engine is started, the rib material will be
sheared off the face of sensor. This will automatically
set sensor air gap.
DISTRIBUTOR
DESCRIPTION
All 5.9L V-8 engines are equipped with a camshaft
driven mechanical distributor (Fig. 23) containing a
shaft driven distributor rotor. All distributors are
equipped with an internal camshaft position (fuel
sync) sensor (Fig. 23).
OPERATION
The distributor does not have built in centrifugal
or vacuum assisted advance. Base ignition timing
and all timing advance is controlled by the Power-
train Control Module (PCM). Because ignition timing
is controlled by the PCM,base ignition timing is
not adjustable.
The distributor is held to the engine in the conven-
tional method using a holddown clamp and bolt.
Although the distributor can be rotated, it will
have no effect on ignition timing.
All distributors contain an internal oil seal that
prevents oil from entering the distributor housing.
The seal is not serviceable.
Fig. 22 SENSOR DEPTH DIMENSIONS ± 8.0L V-10
ENGINE
1 - 2.01888DO NOT INSTALL SENSOR2 - SENSOR MOUNTING HOLE OPENING
3 - SENSOR CENTER LINE
4 - TIMING CHAIN COVER
5 - 1.81888OK TO INSTALL SENSOR
6 - CAM DRIVE GEAR
7 - HIGH MACHINED AREA
8 - LOW MACHINED AREA
Fig. 23 DISTRIBUTOR AND CAMSHAFT POSITION
SENSOR - 5.9L
1 - SYNC SIGNAL GENERATOR
2 - CAMSHAFT POSITION SENSOR
3 - PULSE RING
4 - DISTRIBUTOR ASSEMBLY
8I - 16 IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)

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 cable from battery.
(2) Remove air cleaner tubing.
(3) Remove distributor cap from distributor (two
screws).
(4) Mark the position of distributor housing in
relationship to engine or dash panel. This is done to
aid in installation.
(5) Before distributor is removed, the number one
cylinder must be brought to the Top Dead Center
(TDC) firing position.
(6) Attach a socket to the Crankshaft Vibration
Damper mounting bolt.
(7) 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. 24).
(8) The distributor rotor should now be aligned to
the CYL. NO. 1 alignment mark (stamped) into the
camshaft position sensor (Fig. 25). 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.
Rotor should now be aligned to this position.(9) Disconnect camshaft position sensor wiring
harness from main engine wiring harness.
(10) Remove distributor rotor from distributor
shaft.
(11) Remove distributor holddown clamp bolt and
clamp (Fig. 26). Remove distributor from vehicle.
CAUTION: Do not crank engine with distributor
removed. Distributor/crankshaft relationship will be
lost.
Fig. 24 DAMPER-TO-COVER ALIGNMENT MARKS Ð
TYPICAL
1 - ALIGNMENT MARK
2 - TIMING CHAIN COVER MARKS
3 - CRANKSHAFT VIBRATION DAMPER
Fig. 25 ROTOR ALIGNMENT MARK
1 - CAMSHAFT POSITION SENSOR ALIGNMENT MARK
2 - ROTOR
3 - DISTRIBUTOR
Fig. 26 DISTRIBUTOR HOLDDOWN CLAMP
1 - CLAMP BOLT
2 - HOLDDOWN CLAMP
3 - DISTRIBUTOR HOUSING
DRIGNITION CONTROL 8I - 17
DISTRIBUTOR (Continued)

INSTALLATION
If engine has been cranked while distributor is
removed, establish the relationship between distribu-
tor 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
removed). Then continue to slowly rotate engine
clockwise until indicating mark (Fig. 24) is aligned to
0 degree (TDC) mark on timing chain cover.
(1) Clean top of cylinder block for a good seal
between distributor base and block.
(2) Lightly oil the rubber o-ring seal on the distrib-
utor 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. 25).
(7) Tighten clamp holddown bolt (Fig. 26) 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.
(10) Refer to the following, Checking Distributor
Position.
Checking Distributor Position
To verify correct distributor rotational position, the
DRB scan tool must be used.
WARNING: WHEN PERFORMING THE FOLLOWING
TEST, THE ENGINE WILL BE RUNNING. BE CARE-
FUL NOT TO STAND IN LINE WITH THE FAN
BLADES OR FAN BELT. DO NOT WEAR LOOSE
CLOTHING.
(1) Connect DRB scan tool to data link connector.
The data link connector is located in passenger com-
partment, below and to left of steering column.
(2) Gain access to SET SYNC screen on DRB.
(3) Follow directions on DRB screen and start
engine. Bring to operating temperature (engine must
be in ªclosed loopº mode).
(4) With engine running atidle speed, the words
IN RANGE should appear on screen along with 0É.
This indicates correct distributor position.(5) If a plus (+) or a minus (-) is displayed next to
degree number, and/or the degree displayed is not
zero, loosen but do not remove distributor holddown
clamp bolt. Rotate distributor until IN RANGE
appears on screen. Continue to rotate distributor
until achieving as close to 0É as possible. After
adjustment, tighten clamp bolt to 22.5 N´m (200 in.
lbs.) torque.
Do not attempt to adjust ignition timing using this
method. Rotating distributor will have no effect on
ignition timing. All ignition timing values are con-
trolled by Powertrain Control Module (PCM).
After testing, install air cleaner tubing.
DISTRIBUTOR CAP
DIAGNOSIS AND TESTING - DISTRIBUTOR
CAP - 5.9L V-8
Remove the distributor cap and wipe it clean with
a dry lint free cloth. Visually inspect the cap for
cracks, carbon paths, broken towers or damaged
rotor button (Fig. 27) or (Fig. 28). Also check for
white deposits on the inside (caused by condensation
entering the cap through cracks). Replace any cap
that displays charred or eroded terminals. The
machined surface of a terminal end (faces toward
rotor) will indicate some evidence of erosion from
normal operation. Examine the terminal ends for evi-
dence of mechanical interference with the rotor tip.
Fig. 27 CAP INSPECTIONÐEXTERNALÐTYPICAL
1 - BROKEN TOWER
2 - DISTRIBUTOR CAP
3 - CARBON PATH
4 - CRACK
8I - 18 IGNITION CONTROLDR
DISTRIBUTOR (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)

(6)If necessary, install throttle body air tube or box.
KNOCK SENSOR
DESCRIPTION
The sensors are used only with 3.7L V-6, 4.7L V-8
and 5.7L V-8 engines. On 3.7L V-6 and 4.7L V-8
engines, the 2 knock sensors are bolted into the cyl-
inder block under the intake manifold.
On 5.7L V-8 engines, 2 knock sensors are also
used. These are bolted into each side of the cylinder
block (outside) under the exhaust manifold.
OPERATION
3.7L V-6 / 4.7L V-8 / 5.7L V-8 Engines Only
Two knock sensors are used; one for each cylinder
bank. When the knock sensor detects a knock in one
of the cylinders on the corresponding bank, it sends
an input signal to the Powertrain Control Module
(PCM). In response, the PCM retards ignition timing
for all cylinders by a scheduled amount.
Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal's vibration increases, the
knock sensor output voltage also increases.The voltage signal produced by the knock sensor
increases with the amplitude of vibration. The PCM
receives the knock sensor voltage signal as an input.
If the signal rises above a predetermined level, the
PCM will store that value in memory and retard
ignition timing to reduce engine knock. If the knock
sensor voltage exceeds a preset value, the PCM
retards ignition timing for all cylinders. It is not a
selective cylinder retard.
The PCM ignores knock sensor input during engine
idle conditions. Once the engine speed exceeds a
specified value, knock retard is allowed.
Knock retard uses its own short term and long
term memory program.
Long term memory stores previous detonation
information in its battery-backed RAM. The maxi-
mum authority that long term memory has over tim-
ing retard can be calibrated.
Short term memory is allowed to retard timing up
to a preset amount under all operating conditions (as
long as rpm is above the minimum rpm) except at
Wide Open Throttle (WOT). The PCM, using short
term memory, can respond quickly to retard timing
when engine knock is detected. Short term memory
is lost any time the ignition key is turned off.
NOTE: Over or under tightening the sensor mount-
ing bolts will affect knock sensor performance, pos-
sibly causing improper spark control. Always use
the specified torque when installing the knock sen-
sors.
REMOVAL
3.7L V-6 / 4.7L V-8
The 2 knock sensors are bolted into the cylinder
block under the intake manifold (Fig. 39). or (Fig.
40).
NOTE: The left sensor is identified by an identifica-
tion tag (LEFT). It is also identified by a larger bolt
head. The Powertrain Control Module (PCM) must
have and know the correct sensor left/right posi-
tions. Do not mix the sensor locations.
(1) Disconnect knock sensor dual pigtail harness
from engine wiring harness. This connection is made
near rear of engine.
(2) Remove intake manifold. Refer to Engine sec-
tion.
(3) Remove sensor mounting bolts (Fig. 39), or
(Fig. 40). Note foam strip on bolt threads. This foam
is used only to retain the bolts to sensors for plant
assembly. It is not used as a sealant. Do not apply
any adhesive, sealant or thread locking compound to
these bolts.
Fig. 38 SPARK PLUG CABLE ORDER - 8.0L V-10
DRIGNITION CONTROL 8I - 25
IGNITION COIL (Continued)

NOTE: Over or under tightening the sensor mount-
ing bolts will affect knock sensor performance, pos-
sibly causing improper spark control. Always use
the specified torque when installing the knock sen-
sors. The torque for the knock senor bolt is rela-
tively light for an 8mm bolt.
NOTE: Note foam strip on bolt threads. This foam is
used only to retain the bolts to sensors for plant
assembly. It is not used as a sealant. Do not apply
any adhesive, sealant or thread locking compound
to these bolts.
(3) Install and tighten mounting bolts. Refer to
torque specification.
(4) Install intake manifold. Refer to Engine sec-
tion.
(5) Connect knock sensor wiring harness to engine
harness at rear of intake manifold.
5.7L V-8
(1) Thoroughly clean knock sensor mounting hole.
(2) Install sensor into cylinder block.
NOTE: Over or under tightening the sensor mount-
ing bolts will affect knock sensor performance, pos-
sibly causing improper spark control. Always use
the specified torque when installing the knock sen-
sors. The torque for the knock senor bolt is rela-
tively light for an 8mm bolt.
NOTE: Note foam strip on bolt threads. This foam is
used only to retain the bolts to sensors for plant
assembly. It is not used as a sealant. Do not apply
any adhesive, sealant or thread locking compound
to these bolts.
(3) Install and tighten mounting bolt. Refer to
torque specification.
(4) Install electrical connector to sensor.
SPARK PLUG
DESCRIPTION
Resistor type spark plugs are used on all engines.
Sixteen spark plugs (2 per cylinder) are used with
5.7L V-8 engines.
DIAGNOSIS AND TESTING - SPARK PLUG
CONDITIONS
To prevent possible pre-ignition and/or mechanical
engine damage, the correct type/heat range/number
spark plug must be used.
Always use the recommended torque when tighten-
ing spark plugs. Incorrect torque can distort the
spark plug and change plug gap. It can also pull the
plug threads and do possible damage to both the
spark plug and the cylinder head.
Remove the spark plugs and examine them for
burned electrodes and fouled, cracked or broken por-
celain insulators. Keep plugs arranged in the order
in which they were removed from the engine. A sin-
gle plug displaying an abnormal condition indicates
that a problem exists in the corresponding cylinder.
Replace spark plugs at the intervals recommended in
the Lubrication and Maintenance section.
Spark plugs that have low mileage may be cleaned
and reused if not otherwise defective, carbon or oil
fouled.
CAUTION: Never use a motorized wire wheel brush
to clean the spark plugs. Metallic deposits will
remain on the spark plug insulator and will cause
plug misfire.
Spark plug resistance values range from 6,000 to
20,000 ohms (when checked with at least a 1000 volt
spark plug tester).Do not use an ohmmeter to
check the resistance values of the spark plugs.
Inaccurate readings will result.
NORMAL OPERATING
The few deposits present on the spark plug will
probably be light tan or slightly gray in color. This is
evident with most grades of commercial gasoline
(Fig. 42). There will not be evidence of electrode
burning. Gap growth will not average more than
approximately 0.025 mm (.001 in) per 3200 km (2000
miles) of operation. Spark plugs that have normal
wear can usually be cleaned, have the electrodes
filed, have the gap set and then be installed.
Some fuel refiners in several areas of the United
States have introduced a manganese additive (MMT)
for unleaded fuel. During combustion, fuel with MMT
causes the entire tip of the spark plug to be coated
with a rust colored deposit. This rust color can be
misdiagnosed as being caused by coolant in the com-
bustion chamber. Spark plug performance may be
affected by MMT deposits.
DRIGNITION CONTROL 8I - 27
KNOCK SENSOR (Continued)