The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
3.7L V-6 ENGINE
The 3.7L V-6 engine uses a separate ignition coil
for each cylinder. The one-piece coil bolts directly to
the cylinder head. Rubber boots seal the secondary
terminal ends of the coils to the top of all 6 spark
plugs. A separate electrical connector is used for each
coil.
Because of coil design, spark plug cables (secondary cables) are not used. A distributor is not used
with the 3.7L engine.
Two knock sensors (one for each cylinder bank) are
used to help control spark knock.
Page 2
8I - 2IGNITION CONTROLDR
IGNITION CONTROL (Continued)
The Auto Shutdown (ASD) relay provides battery
voltage to each ignition coil.
The ignition system consists of:
• 6 Spark Plugs
• 6 Separate Ignition Coils
• 2 Knock Sensors
• Powertrain Control Module (PCM)
• Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position, 2 knock and
MAP Sensors
4.7L V-8 ENGINE
The 4.7L V-8 engine uses a separate ignition coil for
each cylinder. The one-piece coil bolts directly to the
cylinder head. Rubber boots seal the secondary terminal ends of the coils to the top of all 8 spark plugs. A
separate electrical connector is used for each coil.
Because of coil design, spark plug cables (secondary cables) are not used. A distributor is not used
with the 4.7L engine.
Two knock sensors (one for each cylinder bank) are
used to help control spark knock.
The Auto Shutdown (ASD) relay provides battery
voltage to each ignition coil.
The ignition system consists of:
• 8 Spark Plugs
• 8 Separate Ignition Coils
• 2 Knock Sensors
• Powertrain Control Module (PCM)
• Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position, 2 knock and
MAP Sensors
and 5/8. These numbers can also be found on the top
of the intake manifold to the right of the throttle
body (Fig. 1).
Two knock sensors (one for each cylinder bank) are
used to help control spark knock.
The 5.7L engine will not use a conventional distrib-
utor.
The ignition system consists of:
• 16 Spark Plugs (2 per cylinder)
•
8 Separate, Dual-Secondary Output, Ignition Coils
• 2 Knock Sensors
• 8 Secondary Ignition Cables
• Powertrain Control Module (PCM)
• Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position, 2 knock and
MAP Sensors
5.7L V-8 ENGINE
For additional information, also refer to Ignition Coil Description and Operation.
The 5.7L V-8 engine is equipped with 16 spark
plugs. Two plugs are used for each cylinder. The 5.7L
is also equipped with 8 separate and independent
ignition coils. The one-piece coil bolts directly to the
cylinder head cover and attaches the coils secondary
output terminal directly to a spark plug using a rubber boot seal. Each coil is also equipped with a second output terminal. This second terminal connects a
conventional spark plug cable directly to a spark
plug on the opposite cylinder bank. A separate primary electrical connector is used for each coil.
Eight conventional spark plug cables are used with
the 5.7L. These cables connect a coil on one cylinder
bank, directly to a spark plug on the opposite cylinder bank. The cables are placed and routed in a special plastic loom to keep them separated. This loom is
clipped to the intake manifold. To prevent a missmatch of cables, a corresponding spark plug / coil
number is displayed on each plug cable: 1/6, 2/3, 4/7
Fig. 1 FIRING ORDER / CABLE ROUTING - 5.7L V-8
ENGINE
1 - TOP OF INTAKE MANIFOLD
2 - CYLINDER FIRING ORDER (IGNITION COIL NUMBER)
3 - CORRESPONDING SPARK PLUG NUMBER
5.9L V-8 ENGINE
The 5.9L V-8 ignition system will use a conventional distributor and 1 remotely mounted coil. Conventional spark plug cables are used with the 5.9L.
Knock sensors are not used with the 5.9L engine.
The ignition system consists of:
• 8 Spark Plugs
• 1 Ignition Coil
• Secondary Ignition Cables
• Distributor (contains rotor and camshaft position
sensor)
• Powertrain Control Module (PCM)
Page 3
DRIGNITION CONTROL8I - 3
IGNITION CONTROL (Continued)
•
Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position, Camshaft Position, Throttle Position and MAP Sensors
8.0L V-10 ENGINE
. The 8.0L V-10 engine is equipped with 2 remote
coil packs. Conventional spark plug cables are used
with the 8.0L engine. The 8.0L engine will not use a
conventional distributor
The ignition coils are individually fired, but each
coil is a dual output. Refer to Ignition Coil for additional information.
Knock sensors are not used with the 8.0L engine.
The ignition system consists of:
• 10 Spark Plugs
• 2 Ignition Coil packs containing 10 individual
coils
• 10 Secondary Ignition Cables
• Powertrain Control Module (PCM)
• Also to be considered part of the ignition system
are certain inputs from the Crankshaft Position,
Camshaft Position, Throttle Position and MAP Sensors
SPECIFICATIONS
SPECIFICATIONS - TORQUE - IGNITION
DESCRIPTIONN·mFt. Lbs.In. Lbs.
Camshaft Position Sensor - 3.7L V-6 Engine12-106
Camshaft Position Sensor - 4.7L V-8 Engine12-106
Camshaft Position Sensor - 5.7L V-8 Engine129105
Camshaft Position Sensor - 8.0L V-10 Engine6-50
Crankshaft Position Sensor - 3.7L V-6 Engine2821205
Crankshaft Position Sensor - 4.7L V-8 Engine2821205
Crankshaft Position Sensor - 5.7L V-8 Engine129105
Crankshaft Position Sensor - 5.9L V-8 Engine8-70
* Do not apply any sealant, thread-locker or adhesive
to bolts. Poor sensor performance may result.
** Torque critical tapered design. Do not exceed 15 ft.
lbs.
5-50
11-100
Page 4
8I - 4IGNITION CONTROLDR
IGNITION CONTROL (Continued)
ENGINE FIRING ORDER - 3.7L V-6
1-6-5-4-3-2
ENGINE FIRING ORDER – 4.7L V-8
FIRING ORDER / CABLE ROUTING – 5.7L V-8
ENGINE
Eight conventional spark plug cables are used with
the 5.7L. These cables connect a coil on one cylinder
bank, directly to a spark plug on the opposite cylinder bank. The cables are placed and routed in a special plastic loom to keep them separated. This loom is
clipped to the intake manifold. To prevent a missmatch of cables, a corresponding spark plug / coil
number is displayed on each plug cable: 1/6, 2/3, 4/7
and 5/8. These numbers can also be found on the top
of the intake manifold to the right of the throttle
body (Fig. 2).
Fig. 2 FIRING ORDER / CABLE ROUTING - 5.7L V-8
ENGINE
1 - TOP OF INTAKE MANIFOLD
2 - CYLINDER FIRING ORDER (IGNITION COIL NUMBER)
3 - CORRESPONDING SPARK PLUG NUMBER
ENGINE FIRING ORDER - 5.9L V-8
Page 5
DRIGNITION CONTROL8I - 5
IGNITION CONTROL (Continued)
SPARK PLUG CABLE ORDER – 8.0L V-10
ENGINE
SPARK PLUG CABLE ORDER – 8.0L V-10 ENGINE
SPARK PLUG CABLE RESISTANCE
MINIMUMMAXIMUM
250 Ohms Per Inch1000 Ohms Per Inch
3000 Ohms Per Foot12,000 Ohms Per Foot
SPARK PLUGS
ENGINEPLUG TYPEELECTRODE GAP
3.7L V-6ZFR6F - 11G (NGK)1.1 (0.042 in.)
4.7L V-8RC12MCC41.01 mm (.040 in.)
5.7L V-8Champion - RE14MCC41.14 mm (.045 in.)
5.9L V-8RC12LC41.01 mm (.040 in.)
8.0L V-10QC9MC41.14 mm (.045 in.)
Page 6
8I - 6IGNITION CONTROLDR
IGNITION CONTROL (Continued)
IGNITION COIL RESISTANCE - 3.7L V-6
PRIMARY RESISTANCE
21-27°C (70-80°F)
0.6 - 0.9 Ohms6,000 - 9,000 Ohms
SECONDARY
RESISTANCE 21-27°C
(70-80°F)
IGNITION COIL RESISTANCE - 4.7L V-8
PRIMARY
RESISTANCE 21-27°C
(70-80°F)
0.6 - 0.9 Ohms6,000 - 9,000 Ohms
SECONDARY
RESISTANCE 21-27°C
(70-80°F)
IGNITION COIL RESISTANCE - 5.9L
COIL MANUFACTURER
Diamond0.97 - 1.18 Ohms11,300 - 15,300 Ohms
Toyodenso0.95 - 1.20 Ohms11,300 - 13,300 Ohms
PRIMARY RESISTANCE
21-27°C (70-80°F)
IGNITION COIL RESISTANCE - 5.7L V-8
PRIMARY RESISTANCE @ 21-27°C (70-80°F)
0.558 - 0.682 Ohms
(Plus or Minus 10% @ 70-80° F)
SECONDARY RESISTANCE 21-27°C
(70-80°F)
IGNITION COIL RESISTANCE – 8.0L V-10
ENGINE
Primary Resistance: 0.53-0.65 Ohms. Test across the
primary connector. Refer to text for test procedures.
Secondary Resistance: 10.9-14.7K Ohms. Test across
the individual coil towers. Refer to text for test
procedures.
IGNITION TIMING
Ignition timing is not adjustable on any engine.
AUTOMATIC SHUT DOWN
RELAY
DESCRIPTION - PCM OUTPUT
The 5–pin, 12–volt, Automatic Shutdown (ASD)
relay is located in the Power Distribution Center
(PDC). Refer to label on PDC cover for relay location.
OPERATION
The ground circuit for the coil within the ASD
relay is controlled by the Powertrain Control Module
(PCM). The PCM operates the ASD relay by switching its ground circuit on and off.
The ASD relay will be shut–down, meaning the
12–volt power supply to the ASD relay will be de-activated by the PCM if:
• the ignition key is left in the ON position. This
is if the engine has not been running for approximately 1.8 seconds.
• there is a crankshaft position sensor signal to
the PCM that is lower than pre-determined values.
OPERATION - ASD SENSE - PCM INPUT
A 12 volt signal at this input indicates to the PCM
that the ASD has been activated. The relay is used to
connect the oxygen sensor heater element, ignition
coil and fuel injectors to 12 volt + power supply.
This input is used only to sense that the ASD relay
is energized. If the Powertrain Control Module
(PCM) does not see 12 volts at this input when the
ASD should be activated, it will set a Diagnostic
Trouble Code (DTC).
OPERATION - PCM OUTPUT
The ASD relay supplies battery voltage (12+ volts)
to the fuel injectors and ignition coil(s). With certain
emissions packages it also supplies 12–volts to the
oxygen sensor heating elements.
Page 7
DRIGNITION CONTROL8I - 7
AUTOMATIC SHUT DOWN RELAY (Continued)
DIAGNOSIS AND TESTING - ASD AND FUEL
PUMP RELAYS
The following description of operation and
tests apply only to the Automatic Shutdown
(ASD) and fuel pump relays. The terminals on the
bottom of each relay are numbered. Two different
types of relays may be used, (Fig. 3) or (Fig. 4).
Fig. 3 TYPE 1 RELAY (ISO MICRO RELAY)
• Terminal number 86 supplies voltage to the coil
side of the relay.
• When the PCM de-energizes the ASD and fuel
pump relays, terminal number 87A connects to terminal 30. This is the Off position. In the off position,
voltage is not supplied to the rest of the circuit. Terminal 87A is the center terminal on the relay.
• When the PCM energizes the ASD and fuel
pump relays, terminal 87 connects to terminal 30.
This is the On position. Terminal 87 supplies voltage
to the rest of the circuit.
The following procedure applies to the ASD and
fuel pump relays.
(1) Remove relay from connector before testing.
(2) With the relay removed from the vehicle, use
an ohmmeter to check the resistance between terminals 85 and 86. The resistance should be 75 ohms +/5 ohms.
(3) Connect the ohmmeter between terminals 30
and 87A. The ohmmeter should show continuity
between terminals 30 and 87A.
(4) Connect the ohmmeter between terminals 87
and 30. The ohmmeter should not show continuity at
this time.
(5) Connect one end of a jumper wire (16 gauge or
smaller) to relay terminal 85. Connect the other end
of the jumper wire to the ground side of a 12 volt
power source.
(6) Connect one end of another jumper wire (16
gauge or smaller) to the power side of the 12 volt
power source. Do not attach the other end of the
jumper wire to the relay at this time.
Fig. 4 ASD AND FUEL PUMP RELAY TERMINALS—
TYPE 2
TERMINAL LEGEND
NUMBERIDENTIFICATION
30COMMON FEED
85COIL GROUND
86COIL BATTERY
87NORMALLY OPEN
87ANORMALLY CLOSED
• Terminal number 30 is connected to battery voltage. For both the ASD and fuel pump relays, terminal 30 is connected to battery voltage at all times.
• The PCM grounds the coil side of the relay
through terminal number 85.
WARNING: DO NOT ALLOW OHMMETER TO CONTACT TERMINALS 85 OR 86 DURING THIS TEST.
DAMAGE TO OHMMETER MAY RESULT.
(7) Attach the other end of the jumper wire to
relay terminal 86. This activates the relay. The ohmmeter should now show continuity between relay terminals 87 and 30. The ohmmeter should not show
continuity between relay terminals 87A and 30.
(8) Disconnect jumper wires.
(9) Replace the relay if it did not pass the continuity and resistance tests. If the relay passed the tests,
it operates properly. Check the remainder of the ASD
and fuel pump relay circuits. Refer to 8, Wiring Diagrams.
REMOVAL
The ASD relay is located in the Power Distribution
Center (PDC) (Fig. 5). Refer to label on PDC cover
for relay location.
(1) Remove PDC cover.
(2) Remove relay from PDC.
Page 8
8I - 8IGNITION CONTROLDR
AUTOMATIC SHUT DOWN RELAY (Continued)
(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
Fig. 5 PDC LOCATION
1 - BATTERY
2 - PDC (POWER DISTRIBUTION CENTER)
INSTALLATION
The ASD relay is located in the Power Distribution
Center (PDC) (Fig. 5). Refer to label on PDC cover
for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
CAMSHAFT POSITION
SENSOR
DESCRIPTION
5.7L V-8
The Camshaft Position Sensor (CMP) on the 5.7L
V-8 engine is located below the generator on the timing chain / case cover on the right/front side of
engine.
5.9L Diesel
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
cover.
5.9L V-8 Gas
The Camshaft Position Sensor (CMP) on the 5.9L
V-8 engine is located inside the distributor.
8.0L V–10
The Camshaft Position Sensor (CMP) on the 8.0L
V-10 engine is located on the timing chain / case
cover on the left/front side of engine.
OPERATION
3.7L V-6
The Camshaft Position Sensor (CMP) sensor on the
3.7L V-6 engine contains a hall effect device referred
to as a sync signal generator. A rotating target wheel
(tonewheel) for the CMP is located at the front of the
camshaft for the right cylinder head (Fig. 6). This
sync signal generator detects notches located on a
tonewheel. As the tonewheel rotates, the notches
pass through the sync signal generator. The signal
from the CMP sensor is used in conjunction with the
Crankshaft Position Sensor (CKP) to differentiate
between fuel injection and spark events. It is also
used to synchronize the fuel injectors with their
respective cylinders.
When the leading edge of the tonewheel notch
enters the tip of the CMP, the interruption of magnetic field causes the voltage to switch high, resulting in a sync signal of approximately 5 volts.
When the trailing edge of the tonewheel notch
leaves then tip of the CMP, the change of the magnetic field causes the sync signal voltage to switch
low to 0 volts.
3.7L V-6
The Camshaft Position Sensor (CMP) on the 3.7L
6-cylinder engine is bolted to the right-front side of
the right cylinder head.
4.7L V-8
The Camshaft Position Sensor (CMP) on the 4.7L
V-8 engine is bolted to the right-front side of the
right cylinder head.
4.7L V-8
The CMP sensor on the 4.7L engine contains a hall
effect device called a sync signal generator to generate a fuel sync signal. This sync signal generator
detects notches located on a tonewheel. The tonewheel is located at the front of the camshaft for the
right cylinder head (Fig. 7). As the tonewheel rotates,
the notches pass through the sync signal generator.
The pattern of the notches (viewed counter-clockwise
from front of engine) is: 1 notch, 2 notches, 3 notches,
Page 9
DRIGNITION CONTROL8I - 9
CAMSHAFT POSITION SENSOR (Continued)
Fig. 6 CMP OPERATION- 3.7L V-6
1 - NOTCHES
2 - RIGHT CYLINDER HEAD
3 - CMP
4 - TONEWHEEL (TARGET WHEEL)
3 notches, 2 notches 1 notch, 3 notches and 1 notch.
The signal from the CMP sensor is used in conjunction with the crankshaft position sensor to differentiate between fuel injection and spark events. It is also
used to synchronize the fuel injectors with their
respective cylinders.
Fig. 7 CMP AND TONEWHEEL OPERATION - 4.7L
V-8
1 - NOTCHES
2 - RIGHT CYLINDER HEAD
3 - CAMSHAFT POSITION SENSOR
4 - TONEWHEEL
5.7L V-8
The CMP sensor is used in conjunction with the
crankshaft position sensor to differentiate between
fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders. The sensor generates electrical pulses. These
pulses (signals) are sent to the Powertrain Control
Module (PCM). The PCM will then determine crankshaft position from both the camshaft position sensor
and crankshaft position sensor.
The tonewheel is located at the front of the camshaft (Fig. 8). As the tonewheel rotates, notches (Fig.
8) pass through the sync signal generator.
When the cam gear is rotating, the sensor will
detect the notches. Input voltage from the sensor to
the PCM will then switch from a low (approximately
0.3 volts) to a high (approximately 5 volts). When the
sensor detects a notch has passed, the input voltage
switches back low to approximately 0.3 volts.
Fig. 8 CMP OPERATION - 5.7L ENGINE
1 - TIMING CHAIN COVER
2 - TONEWHEEL
3 - NOTCHES
Page 10
8I - 10IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)
5.9L V-8 Gas
The CMP sensor on the 5.9L V-8 engine contains a
hall effect device called a sync signal generator to
generate a fuel sync signal. This sync signal generator detects a rotating pulse ring (shutter) (Fig. 9) on
the distributor shaft. The pulse ring rotates 180
degrees through the sync signal generator. Its signal
is used in conjunction with the Crankshaft Position
(CKP) sensor to differentiate between fuel injection
and spark events. It is also used to synchronize the
fuel injectors with their respective cylinders.
When the leading edge of the pulse ring (shutter)
enters the sync signal generator, the following occurs:
The interruption of magnetic field causes the voltage
to switch high resulting in a sync signal of approximately 5 volts.
When the trailing edge of the pulse ring (shutter)
leaves the sync signal generator, the following occurs:
The change of the magnetic field causes the sync signal voltage to switch low to 0 volts.
change of the magnetic field causes the signal voltage
to switch low to 0 volts.
The CMP (Fig. 10) provides a signal to the Engine
Control Module (ECM) at all times when the engine
is running. The ECM uses the CMP information primarily on engine start-up. Once the engine is running, the ECM uses the CMP as a backup sensor for
engine speed. The Crankshaft Position Sensor (CKP)
is the primary engine speed indicator for the engine
after the engine is running.
Fig. 9 CMP / PULSE RING - 5.9L GAS ENGINE
1 - SYNC SIGNAL GENERATOR
2 - CAMSHAFT POSITION SENSOR
3 - PULSE RING
4 - DISTRIBUTOR ASSEMBLY
5.9L Diesel
The Camshaft Position Sensor (CMP) contains a
hall effect device. A rotating target wheel (tonewheel)
for the CMP is located on the front timing gear. This
hall effect device detects notches located on the tonewheel. As the tonewheel rotates, the notches pass the
tip of the CMP.
When the leading edge of the tonewheel notch
passes the tip of the CMP, the following occurs: The
interruption of magnetic field causes the voltage to
switch high resulting in a signal of approximately 5
volts.
When the trailing edge of the tonewheel notch
passes the tip of the CMP, the following occurs: The
The CMP sensor is used in conjunction with the
crankshaft position sensor to differentiate between
fuel injection and spark events. It is also used to synchronize the fuel injectors with their respective cylinders. The sensor generates electrical pulses. These
pulses (signals) are sent to the Powertrain Control
Module (PCM). The PCM will then determine crankshaft position from both the camshaft position sensor
and crankshaft position sensor.
A low and high area are machined into the camshaft drive gear (Fig. 11). The sensor is positioned in
the timing gear cover so that a small air gap (Fig. 11)
exists between the face of sensor and the high
machined area of cam gear.
Page 11
DRIGNITION CONTROL8I - 11
CAMSHAFT POSITION SENSOR (Continued)
When the cam gear is rotating, the sensor will
detect the machined low area. Input voltage from the
sensor to the PCM will then switch from a low
(approximately 0.3 volts) to a high (approximately 5
volts). When the sensor detects the high machined
area, the input voltage switches back low to approximately 0.3 volts.
Fig. 12 CMP LOCATION - 3.7L
1 - RIGHT/FRONT OF RIGHT CYLINDER HEAD
2 - CMP MOUNTING BOLT
3 - CMP LOCATION
Fig. 11 CMP 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
REMOVAL
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 cylinder head (Fig. 12).
(1) Disconnect electrical connector at CMP sensor.
(2) Remove sensor mounting bolt (Fig. 12).
(3) Carefully twist sensor from cylinder head.
(4) Check condition of sensor o-ring.
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 cylinder head (Fig. 13).
(1) Raise and support vehicle.
(2) Disconnect electrical connector at CMP sensor
(Fig. 13).
Fig. 13 CMP LOCATION - 4.7L
1 - RIGHT CYLINDER HEAD
2 - CAMSHAFT POSITION SENSOR
3 - MOUNTING BOLT
4 - ELEC. CONNECTOR
(3) Remove sensor mounting bolt (Fig. 13).
(4) Carefully twist sensor from cylinder head.
(5) Check condition of sensor o-ring.
Page 12
8I - 12IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)
5.7L V-8
The Camshaft Position Sensor (CMP) on the 5.7L
V-8 engine is located on right side of timing chain
cover below generator (Fig. 14).
(1) Disconnect electrical connector at CMP sensor.
The Camshaft Position Sensor (CMP) on the 5.9L
diesel engine is located below the fuel injection
pump. It is bolted to the back of the timing gear
cover (Fig. 16).
(1) Disconnect electrical connector at CMP sensor
(Fig. 16).
(2) Remove sensor mounting bolt.
(3) Carefully twist sensor from timing gear cover.
(4) Check condition of sensor o-ring.
5.9L V-8 Gas
The Camshaft Position Sensor (CMP) is located
inside the distributor (Fig. 17).
Distributor removal is not necessary to remove
camshaft position sensor.
(1) Disconnect negative cable from battery.
(2) Remove air cleaner tubing at throttle body, and
at air filter housing.
(3) Remove distributor cap from distributor (two
screws).
(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).
Fig. 17 DISTRIBUTOR AND CMP LOCATION - 5.9L
1 - SYNC SIGNAL GENERATOR
2 - CAMSHAFT POSITION SENSOR
3 - PULSE RING
4 - DISTRIBUTOR ASSEMBLY
8.0L V–10
The camshaft position sensor is located on the timing chain case/cover on the left-front side of the
engine (Fig. 18).
the 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.
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)
Refer to either of the following procedures; Replacing 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 sensor.
(2) Remove sensor mounting bolt (Fig. 18).
(3) Carefully pry sensor from timing chain case/
cover in a rocking action with two small screwdrivers.
A thin plastic rib is molded into the face of the sensor (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 time
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 screwdrivers.
(4) Remove sensor from vehicle.
Page 14
8I - 14IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)
(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.
Fig. 20 CAMSHAFT SENSOR O-RING – 8.0L
1 - SLOTTED MOUNTING HOLE
2 - SCRIBE LINE
3 - CAMSHAFT POSITION SENSOR O-RING
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 cylinder 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.
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 position 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 sensor mounting tang may result.
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 cylinder 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.
5.9L 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
(5) Install air filter tubing.
(6) Connect battery cable.
Page 15
DRIGNITION CONTROL8I - 15
CAMSHAFT POSITION SENSOR (Continued)
8.0L V–10
If Replacing Old Sensor With Original
The camshaft position sensor is located on the timing 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 electrical damage to the sensor, never use an electric
grinder to remove material from sensor.
(2) From the parts department, obtain a peel-andstick 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 sensor o-ring (Fig. 20).
A low and high area are machined into the camshaft 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 mounting 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.
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
(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 sensor o-ring (Fig. 20).
A low and high area are machined into the camshaft 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.
Page 16
8I - 16IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)
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).
Fig. 22 SENSOR DEPTH DIMENSIONS – 8.0L V-10
ENGINE
1 - 2.01888 DO NOT INSTALL SENSOR
2 - SENSOR MOUNTING HOLE OPENING
3 - SENSOR CENTER LINE
4 - TIMING CHAIN COVER
5 - 1.81888 OK TO INSTALL SENSOR
6 - CAM DRIVE GEAR
7 - HIGH MACHINED AREA
8 - LOW MACHINED AREA
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 mounting 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 camshaft gear.
(7) Install the mounting bolt and tighten to 6 N·m
(50 in. lbs.) torque.
(8) Connect sensor wiring harness to engine harness.
Fig. 23 DISTRIBUTOR AND CAMSHAFT POSITION
SENSOR - 5.9L
1 - SYNC SIGNAL GENERATOR
2 - CAMSHAFT POSITION SENSOR
3 - PULSE RING
4 - DISTRIBUTOR ASSEMBLY
OPERATION
The distributor does not have built in centrifugal
or vacuum assisted advance. Base ignition timing
and all timing advance is controlled by the Powertrain 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 conventional 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.
Page 17
DRIGNITION CONTROL8I - 17
DISTRIBUTOR (Continued)
REMOVAL
CAUTION: Base ignition timing is not adjustable on
any engine. Distributors do not have built in centrifugal or vacuum assisted advance. Base ignition
timing and timing advance are controlled by the
Powertrain Control Module (PCM). Because a conventional timing light can not be used to adjust distributor 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).
1 - CAMSHAFT POSITION SENSOR ALIGNMENT MARK
2 - ROTOR
3 - DISTRIBUTOR
(9) Disconnect camshaft position sensor wiring
harness from main engine wiring harness.
(10) Removedistributor rotorfrom distributor
shaft.
(11) Remove distributor holddown clamp bolt and
clamp (Fig. 26). Remove distributor from vehicle.
Fig. 25 ROTOR ALIGNMENT MARK
Fig. 24 DAMPER-TO-COVER ALIGNMENT MARKS —
TYPICAL
1 - ALIGNMENT MARK
2 - TIMING CHAIN COVER MARKS
3 - CRANKSHAFT VIBRATION DAMPER
(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.
CAUTION: Do not crank engine with distributor
removed. Distributor/crankshaft relationship will be
lost.
Page 18
8I - 18IGNITION CONTROLDR
DISTRIBUTOR (Continued)
INSTALLATION
If engine has been cranked while distributor is
removed, 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
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 distributor 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 camshaft 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 harness to main engine harness.
(9) Installdistributorcap.Tightenmounting
screws.
(10) Refer to the following, Checking 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 0° 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 controlled 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 evidence of mechanical interference with the rotor tip.
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 CAREFUL 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 compartment, 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 “closed loop” mode).
(4) With engine running at idle speed, the words
IN RANGE should appear on screen along with 0°.
This indicates correct distributor position.
The 3.7L V-6 engine uses 6 dedicated, and individually fired coil for each spark plug (Fig. 30). Each
coil is mounted directly into the cylinder head and
onto the top of each spark plug (Fig. 31).
Fig. 28 CAP INSPECTION—INTERNAL—TYPICAL
1 - CHARRED OR ERODED TERMINALS
2 - WORN OR DAMAGED ROTOR BUTTON
3 - CARBON PATH
DISTRIBUTOR ROTOR
DIAGNOSIS AND TESTING - DISTRIBUTOR
ROTOR - 5.9L V-8
Visually inspect the rotor (Fig. 29) for cracks, evidence of corrosion or the effects of arcing on the metal
tip. Also check for evidence of mechanical interference
with the cap. Some charring is normal on the end of
the metal tip. The silicone-dielectric-varnish-compound
applied to the rotor tip for radio interference noise suppression, will appear charred. This is normal. Do not
remove the charred compound.
insufficient tension. Replace a rotor that displays any
of these adverse conditions.
1 - INSUFFICIENT SPRING TENSION
2 - CRACKS
3 - EVIDENCE OF PHYSICAL CONTACT WITH CAP
4 - ROTOR TIP CORRODED
Fig. 31 IGNITION COIL LOCATION - 3.7L V-6
1 - IGNITION COIL
2 - COIL MOUNTING NUT
Page 20
8I - 20IGNITION CONTROLDR
IGNITION COIL (Continued)
4.7L V-8
The 4.7L V–8 engine uses 8 dedicated, and individually fired coil (Fig. 30) for each spark plug. Each
coil is mounted directly to the top of each spark plug
(Fig. 32).
The 5.7L V–8 engine uses 8 dedicated, and individually fired coil (Fig. 33) for each pair of spark plugs.
Each coil is mounted directly to the top of each spark
plug (Fig. 34). Each coil is bolted to the valve cover.
5.9L V-8
A single ignition coil is used (Fig. 35) or (Fig. 36).
The coil is not oil filled. The coil windings are embedded in an epoxy compound. This provides heat and
vibration resistance thatallows the coil to be
mounted on the engine.
8.0L V-10
Two separate coil packs containing a total of five
independent coils are attached to a common mounting bracket. They are located above the right engine
valve cover (Fig. 37). The coil packs are not oil filled.
The front coil pack contains three independent epoxy
filled coils. The rear coil pack contains two independent epoxy filled coils.
Battery voltage is supplied to the 6 individual ignition coils from the ASD relay. The Powertrain Control Module (PCM) opens and closes each ignition coil
ground circuit at a determined time for ignition coil
operation.
Base ignition timing is not adjustable. By controlling the coil ground circuit, the PCM is able to set
the base timing and adjust the ignition timing
advance. This is done to meet changing engine operating conditions.
The ignition coil is not oil filled. The windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the ignition coil
to be mounted on the engine.
Because of coil design, spark plug cables (secondary cables) are not used with the 3.7L V-6 engine.
Battery voltage is supplied to the 8 individual ignition coils from the ASD relay. The Powertrain Control Module (PCM) opens and closes each ignition coil
ground circuit at a determined time for ignition coil
operation.
Base ignition timing is not adjustable. By controlling the coil ground circuit, the PCM is able to set
the base timing and adjust the ignition timing
advance. This is done to meet changing engine operating conditions.
The ignition coil is not oil filled. The windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the ignition coil
to be mounted on the engine.
Because of coil design, spark plug cables (secondary cables) are not used with the 4.7L V-8 engine.
5.7L V-8
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
A “wasted spark” system is used on the 5.7L
engine combining paired, or dual-firing coils, and 2
spark plugs per cylinder. The coils and spark plugs
are connected with paired, secondary high-voltage
cables.
Each cylinder is equipped with 1 dual-output coil.
Meaning one coil mounts directly over one of the
dual spark plugs for 1 high-voltage output. A second
high-voltage output is supplied directly from the
same coil (using a plug cable) to one of the dual
spark plugs on a corresponding (paired) cylinder on
the opposite cylinder bank.
Each coil fires 2 spark plugs simultaneously on
each of the cylinder banks (one cylinder on compression stroke and one cylinder on exhaust stroke).
EXAMPLE : When the #1 cylinder is on compression
stroke and ready for spark, the #1 coil will fire one of
the dual spark plugs on the #1 cylinder (directly
below the coil). The other dual spark plug on the #1
cylinder will be fired by the #6 coil. At the same
time, the #1 coil will fire a “wasted spark” to one of
the dual spark plugs at the #6 cylinder as coil #6 also
fires a “wasted spark” to one of the dual spark plugs
at the #6 cylinder.
The firing order is paired at cylinders 1/6, 2/3, 4/7,
5/8. Basic cylinder firing order is 1–8–4–3–6–5–7–2.
Battery voltage is supplied to all of the ignition
coils positive terminals from the ASD relay. If the
PCM does not see a signal from the crankshaft and
camshaft sensors (indicating the ignition key is ON
but the engine is not running), it will shut down the
ASD circuit.
Base ignition timing is not adjustable on the
5.7L V-8 engine. By controlling the coil ground cir-
cuits, the PCM is able to set the base timing and
adjust the ignition timing advance. This is done to
meet changing engine operating conditions.
The PCM adjusts ignition timing based on inputs it
receives from:
• The engine coolant temperature sensor
• The crankshaft position sensor (engine speed)
• The camshaft position sensor (crankshaft posi-
tion)
• The manifold absolute pressure (MAP) sensor
• The throttle position sensor
• Transmission gear selection
5.9L V-8
A single ignition coil is used. The Powertrain Control Module (PCM) opens and closes the ignition coil
ground circuit for ignition coil operation.
Battery voltage is supplied to the ignition coil positive terminal from the ASD relay. If the PCM does
not see a signal from the crankshaft and camshaft
sensors (indicating the ignition key is ON but the
engine is not running), it will shut down the ASD circuit.
Base ignition timing is not adjustable on any
engine. By controlling the coil ground circuit, the
PCM is able to set the base timing and adjust the
ignition timing advance. This is done to meet changing engine operating conditions.
Conventional spark plug cables (secondary cables)
are used with the 5.9L V-8 engine.
8.0L V-10
When one of the 5 independent coils discharges, it
fires two paired cylinders at the same time (one cylinder on compression stroke and the other cylinder
on exhaust stroke).
Coil firing is paired together on cylinders:
• Number 5 and 10
• Number 9 and 8
• Number 1 and 6
• Number 7 and 4
• Number 3 and 2
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
Battery voltage is supplied to all of the ignition
coils positive terminals from the ASD relay. If the
PCM does not see a signal from the crankshaft and
camshaft sensors (indicating the ignition key is ON
but the engine is not running), it will shut down the
ASD circuit.
Conventional spark plug cables (secondary cables)
are used with the 8.0L V-10 engine.
Base ignition timing is not adjustable on the
8.0L V-10 engine. By controlling the coil ground cir-
cuits, the PCM is able to set the base timing and
adjust the ignition timing advance. This is done to
meet changing engine operating conditions.
Page 23
DRIGNITION CONTROL8I - 23
IGNITION COIL (Continued)
The PCM adjusts ignition timing based on inputs it
receives from:
• The engine coolant temperature sensor
• The crankshaft position sensor (engine speed)
• The camshaft position sensor (crankshaft posi-
tion)
• The manifold absolute pressure (MAP) sensor
• The throttle position sensor
• Transmission 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 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. 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 cylinder 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 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. 31).
(5) Carefully pull up coil from cylinder head opening 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 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. 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 cylinder 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 opening 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 cables MUST be 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 opening 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.
Page 24
8I - 24IGNITION CONTROLDR
IGNITION COIL (Continued)
WARNING: 5.9L V-8 LDC-GAS ENGINES: DO NOT
REMOVE THE COIL MOUNTING BRACKET-TO-CYLINDERHEADMOUNTINGBOLTS.THECOIL
MOUNTINGBRACKETISUNDER 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) Removeignitioncoilfromcoilmounting
bracket (two bolts).
8.0L V-10
Two separate coil packs containing a total of five
independent coils are attached to a common mounting 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 contaminants 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 contaminants 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 crossfire, spark plug cables MUST be 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 (primary wiring connectors face downward).
(2) Install coil pack mounting bolts. Tighten bolts
to 10 N·m (90 in. lbs.) torque.
(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.
Page 25
DRIGNITION CONTROL8I - 25
IGNITION COIL (Continued)
(6)
If necessary, install throttle body air tube or box.
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 maximum authority that long term memory has over timing 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.
Fig. 38 SPARK PLUG CABLE ORDER - 8.0L V-10
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 cylinder 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.
NOTE: Over or under tightening the sensor mounting bolts will affect knock sensor performance, possibly causing improper spark control. Always use
the specified torque when installing the knock sensors.
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 identification 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 positions. 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 section.
(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.
Page 26
8I - 26IGNITION CONTROLDR
KNOCK SENSOR (Continued)
(4) Remove sensors from engine.5.7L V8
Two sensors are used. Each sensor is bolted into
the outside of cylinder block below the exhaust manifold (Fig. 41).
(1) Raise vehicle.
(2) Disconnect knock sensor electrical connector.
(3) Remove sensor mounting bolt (Fig. 41). 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.
NOTE: The left sensor is identified by an identification 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 positions. Do not mix the sensor locations.
(1) Thoroughly clean knock sensor mounting holes.
(2) Install sensors into cylinder block.
Page 27
DRIGNITION CONTROL8I - 27
KNOCK SENSOR (Continued)
NOTE: Over or under tightening the sensor mounting bolts will affect knock sensor performance, possibly causing improper spark control. Always use
the specified torque when installing the knock sensors. The torque for the knock senor bolt is relatively 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.
NOTE: Over or under tightening the sensor mounting bolts will affect knock sensor performance, possibly causing improper spark control. Always use
the specified torque when installing the knock sensors. The torque for the knock senor bolt is relatively 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 tightening 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 porcelain insulators. Keep plugs arranged in the order
in which they were removed from the engine. A single 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 combustion chamber. Spark plug performance may be
affected by MMT deposits.
Page 28
8I - 28IGNITION CONTROLDR
SPARK PLUG (Continued)
Fig. 42 NORMAL OPERATION AND COLD (CARBON)
FOULING
1 - NORMAL
2 - DRY BLACK DEPOSITS
3 - COLD (CARBON) FOULING
COLD FOULING/CARBON FOULING
Cold fouling is sometimes referred to as carbon
fouling. The deposits that cause cold fouling are basically carbon (Fig. 42). A dry, black deposit on one or
two plugs in a set may be caused by sticking valves
or defective spark plug cables. Cold (carbon) fouling
of the entire set of spark plugs may be caused by a
clogged air cleaner element or repeated short operating times (short trips).
WET FOULING OR GAS FOULING
A spark plug coated with excessive wet fuel or oil
is wet fouled. In older engines, worn piston rings,
leaking valve guide seals or excessive cylinder wear
can cause wet fouling. In new or recently overhauled
engines, wet fouling may occur before break-in (normal oil control) is achieved. This condition can usually be resolved by cleaning and reinstalling the
fouled plugs.
OIL OR ASH ENCRUSTED
If one or more spark plugs are oil or oil ash
encrusted (Fig. 43), evaluate engine condition for the
cause of oil entry into that particular combustion
chamber.
ELECTRODE GAP BRIDGING
Electrode gap bridging may be traced to loose
deposits in the combustion chamber. These deposits
accumulate on the spark plugs during continuous
stop-and-go driving. When the engine is suddenly
subjected to a high torque load, deposits partially liquefy and bridge the gap between electrodes (Fig. 44).
This short circuits the electrodes. Spark plugs with
Fig. 43 OIL OR ASH ENCRUSTED
electrode gap bridging can be cleaned using standard
procedures.
Fuel scavenger deposits may be either white or yellow (Fig. 45). They may appear to be harmful, but
this is a normal condition caused by chemical additives in certain fuels. These additives are designed to
change the chemical nature of deposits and decrease
spark plug misfire tendencies. Notice that accumulation on the ground electrode and shell area may be
heavy, but the deposits are easily removed. Spark
plugs with scavenger deposits can be considered nor-
Page 29
DRIGNITION CONTROL8I - 29
SPARK PLUG (Continued)
mal in condition and can be cleaned using standard
procedures.
Fig. 45 SCAVENGER DEPOSITS
1 - GROUND ELECTRODE COVERED WITH WHITE OR YELLOW
DEPOSITS
2 - CENTER ELECTRODE
CHIPPED ELECTRODE INSULATOR
A chipped electrode insulator usually results from
bending the center electrode while adjusting the
spark plug electrode gap. Under certain conditions,
severe detonation can also separate the insulator
from the center electrode (Fig. 46). Spark plugs with
this condition must be replaced.
Determine if ignition timing is over advanced or if
other operating conditions are causing engine overheating. (The heat range rating refers to the operating temperature of a particular type spark plug.
Spark plugs are designed to operate within specific
temperature ranges. This depends upon the thickness and length of the center electrodes porcelain
insulator.)
Fig. 47 PREIGNITION DAMAGE
1 - GROUND ELECTRODE STARTING TO DISSOLVE
2 - CENTER ELECTRODE DISSOLVED
SPARK PLUG OVERHEATING
Overheating is indicated by a white or gray center
electrode insulator that also appears blistered (Fig.
48). The increase in electrode gap will be considerably in excess of 0.001 inch per 2000 miles of operation. This suggests that a plug with a cooler heat
range rating should be used. Over advanced ignition
timing, detonation and cooling system malfunctions
can also cause spark plug overheating.
Preignition damage is usually caused by excessive
combustion chamber temperature. The center electrode dissolves first and the ground electrode dissolves somewhat latter (Fig. 47). Insulators appear
relatively deposit free. Determine if the spark plug
has the correct heat range rating for the engine.
Fig. 48 SPARK PLUG OVERHEATING
1 - BLISTERED WHITE OR GRAY COLORED INSULATOR
Page 30
8I - 30IGNITION CONTROLDR
SPARK PLUG (Continued)
REMOVAL
3.7L V-6
Each individual spark plug is located under each
ignition coil. Each individual ignition coil must be
removed to gain access to each spark plug. Refer to
Ignition Coil Removal/Installation.
(1) Remove necessary air filter tubing at throttle
body.
(2) Prior to removing ignition coil, spray compressed air around coil base at cylinder head.
(3) Prior to removing spark plug, spray compressed air into cylinder head opening. This will help
prevent foreign material from entering combustion
chamber.
(4) Remove spark plug from cylinder head using a
quality socket with a rubber or foam insert. Also
check condition of ignition coil o-ring and replace as
necessary.
(5) Inspect spark plug condition. Refer to Diagnostics and Testing - Spark Plug Conditions.
4.7L V-8
Each individual spark plug is located under each
ignition coil. Each individual ignition coil must be
removed to gain access to each spark plug. Refer to
Ignition Coil Removal/Installation.
(1) Remove necessary air filter tubing at throttle
body.
(2) Prior to removing ignition coil, spray compressed air around coil base at cylinder head.
(3) Prior to removing spark plug, spray compressed air into cylinder head opening. This will help
prevent foreign material from entering combustion
chamber.
(4) Remove spark plug from cylinder head using a
quality socket with a rubber or foam insert. Also
check condition of ignition coil o-ring and replace as
necessary.
(5) Inspect spark plug condition. Refer to Diagnostics and Testing - Spark Plug Conditions.
Before installing spark plug cables to either the
spark plugs or coils, apply dielectric grease to inside
of boots.
(1) Remove necessary air filter tubing at throttle
body.
(2) Prior to removing ignition coil (if coil removal
is necessary), spray compressed air around coil base
at cylinder head cover.
(3) Prior to removing spark plug, spray compressed air into cylinder head opening. This will help
prevent foreign material from entering combustion
chamber.
(4) Remove spark plug from cylinder head using a
quality socket with a rubber or foam insert.
(5) Inspect spark plug condition. Refer to Diagnostics and Testing - Spark Plug Conditions.
5.9L V-8
On 5.9L V-8 engines, spark plug cable heat shields
are pressed into the cylinder head to surround each
cable boot and spark plug (Fig. 49).
(1) Always remove spark plug or ignition coil
cables by grasping at the cable boot (Fig. 50). Turn
the cable boot 1/2 turn and pull straight back in a
steady motion. Never pull directly on the cable.
Internal damage to cable will result.
(2) Prior to removing the spark plug, spray compressed 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 Diagnostics and Testing - Spark Plug Conditions.
5.7L V-8
Eight of the 16 spark plugs are located under an
ignition coil; the other 8 are not. If spark plug being
removed is under coil, coil must be removed to gain
access to spark plug. Refer to Ignition Coil Removal/
Installation and observe all CAUTIONS and WARNINGS.
Before removing or disconnecting any spark plug
cables, note their original position. Remove cables
one-at-a-time. To prevent ignition crossfire, spark
plug cables MUST be placed in cable tray (routing
loom) into their original position. Refer to Spark Plug
Cable Removal for a graphic.
(1) Always remove spark plug or ignition coil
cables by grasping at the cable boot (Fig. 50). Turn
the cable boot 1/2 turn and pull straight back in a
steady motion. Never pull directly on the cable.
Internal damage to cable will result.
(2) Prior to removing the spark plug, spray compressed 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 Diagnostics and Testing - Spark Plug Conditions.
CLEANING
CLEANING AND ADJUSTMENT
The plugs may be cleaned using commercially
available spark plug cleaning equipment. After cleaning, file center electrode flat with a small point file or
jewelers file before adjusting gap.
CAUTION: Never use a motorized wire wheel brush
to clean spark plugs. Metallic deposits will remain
on spark plug insulator and will cause plug misfire.
Fig. 51 SETTING SPARK PLUG GAP - TYPICAL
1 - GAUGE TOOL
2 - SPARK PLUG
INSTALLATION
3.7L V-6
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.
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 specifications.
(3) Before installing ignition coil(s), check condition 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.
Adjust spark plug gap with a gap gauging tool
(Fig. 51).
Page 32
8I - 32IGNITION CONTROLDR
SPARK PLUG (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 substituted, 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 electrodes 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 specifications.
(3) Before installing ignition coil(s), check condition 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
MUST be 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 electrodes 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 specifications.
(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 electrodes 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 specifications.
(3) Install spark plug cables to spark plugs.
Page 33
DRIGNITION CONTROL8I - 33
IGNITION COIL CAPACITOR
DESCRIPTION
One coil capacitor is used. It is located in the right-
rear section of the engine compartment.
OPERATION
The coil capacitor(s) help dampen the amount of
conducted electrical noise to the camshaft position
sensor, crankshaft position sensor, and throttle position sensor. This noise is generated on the 12V supply wire to the ignition coils and fuel injectors.
REMOVAL
The coil capacitor is located in the right-rear section of the engine compartment. It is attached with a
mounting stud and nut.
(1) Disconnect electrical connector at capacitor
(Fig. 52).
(4) Connect electrical connector to coil capacitor.
SPARK PLUG CABLE
DESCRIPTION
Spark plug cables are sometimes referred to as sec-
ondary ignition wires, or secondary ignition cables.
Plug cables are used only on the 5.7L V-8, 5.9L V-8
and 8.0L V-10 engines.
OPERATION
The spark plug cables transfer electrical current
from the ignition coil(s) and/or distributor, to individual spark plugs at each cylinder. The resistive spark
plug cables are of nonmetallic construction. The
cables provide suppression of radio frequency emissions from the ignition system.
Plug cables are used only on the 5.7L V-8, 5.9L V-8
and 8.0L V-10 engines.
DIAGNOSIS AND TESTING - SPARK PLUG
CABLES
Cable routing is important on certain engines. To
prevent possible ignition crossfire, be sure the cables
are clipped into the plastic routing looms. Refer to
Spark Plug Cable Removal for addditional information. Try to prevent any one cable from contacting
another. Before removing cables, note their original
location and routing. Never allow one cable to be
twisted around another.
Check the spark plug cable connections for good
contact at the coil(s), distributor cap towers (if applicaple), and spark plugs. Terminals should be fully
seated. The insulators should be in good condition
and should fit tightly on the coil, distributor and
spark plugs. Spark plug cables with insulators that
are cracked or torn must be replaced.
Clean high voltage ignition cables with a cloth
moistened with a non-flammable solvent. Wipe the
cables dry. Check for brittle or cracked insulation.
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).
TESTING
When testing secondary cables for damage with an
oscilloscope, follow the instructions of the equipment
manufacturer.
If an oscilloscope is not available, spark plug cables
may be tested as follows:
Page 34
8I - 34IGNITION CONTROLDR
SPARK PLUG CABLE (Continued)
Use an ohmmeter to test for open circuits, excessive resistance or loose terminals. If equipped,
remove the distributor cap from the distributor. Donot remove cables from cap. Remove cable from
spark plug. Connect ohmmeter to spark plug terminal end of cable and to corresponding electrode in
distributor cap. Resistance should be 250 to 1000
Ohms per inch of cable. If not, remove cable from distributor cap tower and connect ohmmeter to the terminal ends of cable. If resistance is not within
specifications as found in the SPARK PLUG CABLE
RESISTANCE chart, replace the cable. Test all spark
plug cables in this manner.
SPARK PLUG CABLE RESISTANCE
Fig. 53 HEAT SHIELDS - 5.9L V-8
1 - AIR GAP
2 - SPARK PLUG BOOT HEAT SHIELD
CAUTION: Do not leave any one spark plug cable
disconnected for longer than necessary during testing. This may cause possible heat damage to the
catalytic converter. Total test time must not exceed
ten minutes.
Except 5.7L V-8 : With the engine running,
remove spark plug cable from spark plug (one at a
time) and hold next to a good engine ground. If the
cable and spark plug are in good condition, the
engine rpm should drop and the engine will run
poorly. If engine rpm does not drop, the cable and/or
spark plug may not be operating properly and should
be replaced. Also check engine cylinder compression.
With the engine not running, connect one end of a
test probe to a good ground. Start the engine and run
the other end of the test probe along the entire
length of all spark plug cables. If cables are cracked
or punctured, there will be a noticeable spark jump
from the damaged area to the test probe. The cable
running from the ignition coil to the distributor cap
can be checked in the same manner. Cracked, damaged or faulty cables should be replaced with resistance type cable. This can be identified by the words
ELECTRONIC SUPPRESSION printed on the cable
jacket.
MINIMUMMAXIMUM
250 Ohms Per Inch1000 Ohms Per Inch
3000 Ohms Per Foot12,000 Ohms Per Foot
To test ignition coil-to-distributor cap cable (if
applicaple), do not remove the cable from the cap.
Connect ohmmeter to rotor button (center contact) of
distributor cap and terminal at ignition coil end of
cable. If resistance is not within specifications as
found in the Spark Plug Cable Resistance chart,
remove the cable from the distributor cap. Connect
the ohmmeter to the terminal ends of the cable. If
resistance is not within specifications as found in the
Spark Plug Cable Resistance chart, replace the cable.
Inspect the ignition coil tower for cracks, burns or
corrosion.
REMOVAL
5.9L V-8 / 8.0L V-10
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
(Fig. 54). Grasp the boot (not the cable) and pull it
off with a steady, even force.
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).
Page 35
DRIGNITION CONTROL8I - 35
SPARK PLUG CABLE (Continued)
MUST be placed in cable tray (routing loom) into
their original position. The cable retention clips (Fig.
55) must also be securly locked.
Before installing spark plug cables to either the
spark plugs or coils, apply dielectric grease to inside
of boots.
If cable tray removal is necessary, release the 4
tray-to-manifold retention clips (Fig. 55).
INSTALLATION
Install cables into the proper engine cylinder firing
order sequence. Refer to Specifications.
When replacing the spark plug and coil cables,
route the cables correctly and secure them in the
proper retainers. Failure to route the cables properly
may cause the radio to reproduce ignition noise. It
Spark plug cables on the 5.7L engine are paired on
cylinders 1/6, 2/3, 4/7 and 5/8. Before removing or
disconnecting any spark plug cables, note their original position (Fig. 55). Remove cables one-at-a-time.
To prevent ignition crossfire, spark plug cables
could also cause cross-ignition of the plugs, or, may
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.