
engine is operating, the smaller the pulse width on
the oscilloscope.
By counting the pulses and referencing the pulse
from the 60 degree signature notch, the PCM calcu-
lates crankshaft angle (position). In each group of
timing reference notches, the first notch represents
69 degrees before top dead center (BTDC). The sec-
ond notch represents 49 degrees BTDC. The third
notch represents 29 degrees. The last notch in each
set represents 9 degrees before top dead center
(TDC).
The timing reference notches are machined to a
uniform width representing 13.6 degrees of crank-
shaft rotation. From the voltage pulse width the
PCM tells the difference between the timing refer-
ence notches and the 60 degree signature notch. The
60 degree signature notch produces a longer pulse
width than the smaller timing reference notches. If
the camshaft position sensor input switches from
high to low when the 60 degree signature notch
passes under the crankshaft position sensor, the
PCM knows cylinder number one is the next cylinder
at TDC.
The crankshaft position sensor mounts to the
engine block behind the generator, near the oil filter
(Fig. 8).
CAMSHAFT POSITION SENSOR
The PCM determines fuel injection synchronization
and cylinder identification from inputs provided by
the camshaft position sensor and crankshaft position
sensor. From the two inputs, the PCM determines
crankshaft position.The camshaft position sensor attaches to the rear
of the cylinder head (Fig. 2). A target magnet
attaches to the rear of the camshaft and indexes to
the correct position (Fig. 3). The target magnet has
four different poles arranged in an asymmetrical pat-
tern. As the target magnet rotates, the camshaft
position sensor senses the change in polarity (Fig. 4).
The sensor output switch switches from high (5.0
volts) to low (0.30 volts) as the target magnet rotates.
When the north pole of the target magnet passes
under the sensor, the output switches high. The sen-
sor output switches low when the south pole of the
target magnet passes underneath.
INTAKE AIR TEMPERATURE SENSORÐ2.4L
The intake air temperature sensor measures the
temperature of the air as it enters the engine. The
sensor supplies one of the inputs the PCM uses to
determine injector pulse width and spark advance.
The intake air temperature sensor threads into the
intake manifold (Fig. 5).
Fig. 2 Crankshaft Position Sensor
Fig. 3 Target Magnet
Fig. 4 Target Magnet Polarity
NSIGNITION SYSTEM 8D - 17
DESCRIPTION AND OPERATION (Continued)

REMOVAL AND INSTALLATION
SPARK PLUG CABLE SERVICEÐ2.4L
The cables insulate the spark plugs and covers the
top of the spark plug tube (Fig. 6). To remove the
cables, lightly grasp the top of the cable. Rotate the
insulator 90É and pull straight up. To replace the
cables, disconnect the cable from the ignition coil.
Ensure the #1 and #4 cables run under the #2
and #3 ignition coil towers. Keep #4 cable away
from the oil fill cap.
SPARK PLUG SERVICE
When replacing the spark plugs and spark plug
cables, route the cables correctly and secure them inthe appropriate retainers. Failure to route the cables
properly can cause the radio to reproduce ignition
noise, cross ignition of the spark plugs orshort cir-
cuit the cables to ground.
Never Wire Brush Spark Plugs.The spark plug
insulator tip is harder than the bristles of wire
brushes. Bristles of wire brushes can leave a conduc-
tive, metallic film on the insulator which could lead
to conductive deposits. Conductive deposits can cause
spark plug failure and engine misfire. Use a jewelers
file to remove deposits from the electrode gap or use
a spark plug cleaning machine to clean spark plugs.
REMOVAL
Always remove cables by grasping at the boot,
rotating the boot 1/2 turn, and pulling straight back
in a steady motion.
(1) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug.
(2) Remove the spark plug using a quality socket
with a foam insert.
(3) Inspect the spark plug condition. Refer to
Spark Plug Condition in this section.
INSTALLATION
(1) To avoid cross threading, start the spark plug
into the cylinder head by hand.
(2) Tighten spark plugs to 28 N´m (20 ft. lbs.)
torque.
(3) Install spark plug cables over spark plugs. A
click will be heard and felt when the cable properly
attaches to the spark plug.
IGNITION COILÐ2.4L
REMOVAL
REMOVAL
(1) Remove spark plug cables from coil (Fig. 7).
Always twist the coil boots to break the seal with the
coil and pull straight back on the boot.
(2) Remove ignition coil electrical connector.
(3) Remove ignition coil mounting bolts, throttle
cable bracket or clip.
(4) Remove ignition coil.
INSTALLATION
(1) Reverse the above procedure for installation.
Tighten mounting screws to 12 N´m (105 in. lbs.)
torque.
(2) Transfer ignition cables to new coil pack. The
coil pack towers and cables are numbered with cylin-
der identification.
Fig. 5 Intake Air Temperature Sensor
Fig. 6 Spark Plug Cables
8D - 18 IGNITION SYSTEMNS
DESCRIPTION AND OPERATION (Continued)

CRANKSHAFT POSITION SENSOR
The crankshaft position sensor mounts to the
engine block behind the generator, just behind the oil
filter (Fig. 8).
REMOVAL
(1) Raise and support vehicle.
(2) Disconnect electrical connector from crankshaft
position sensor.
(3) Remove sensor mounting screw.
(4) Pull crankshaft position sensor straight out.
INSTALLATION
NOTE: If the removed sensor is to be reinstalled,
clean off the old spacer on the sensor face. A NEW
SPACER must be attached to the sensor face before
installation. If the sensor is being replaced, confirm
that the paper spacer is attached to the face of the
new sensor.
(1) Install sensor and push sensor down until con-
tact is made. While holding the sensor in this posi-
tion, and install and tighten the retaining bolt to 11.9
N´m (105 in. lbs.) torque.
CAMSHAFT POSITION SENSOR
The camshaft position sensor is mounted to the
rear of the cylinder head (Fig. 9).
REMOVAL
(1) Disconnect the filtered air tube from the throt-
tle body and air cleaner housing. Disconnect the airtube from the oil separator hose. Remove filtered air
tube.
(2) Remove the air cleaner inlet tube.
(3) Disconnect engine harness connector from cam-
shaft position sensor.
(4) Remove camshaft position sensor mounting
screws. Remove sensor.
(5) Loosen screw attaching target magnet to rear
of camshaft (Fig. 10).
INSTALLATION
The target magnet has locating dowels that fit into
off-set machined locating holes in end of the cam-
shaft (Fig. 11).
Fig. 7 Ignition Coil RemovalFig. 8 Crankshaft Position Sensor
Fig. 9 Camshaft Position Sensor Location
NSIGNITION SYSTEM 8D - 19
REMOVAL AND INSTALLATION (Continued)

SPECIFICATIONS
IGNITION COIL
SPARK PLUG
TORQUE
DESCRIPTION......................TORQUE
2.4L Target Magnet Screw.......3N´m(30in.lbs.)
2.4L Camshaft Position Sensoe Screw . .9 N´m (80 in.
lbs.)
Ignition Switch...............2N´m(17in.lbs.)
Spark Plugs.................28N´m(60in.lbs.)
SPARK PLUG CABLE RESISTANCEÐ2.4L
Coil ManufacturePrimary Resistance at 21ÉC-27ÉC
(70ÉF-80ÉF)Secondary Resistance at 21ÉC-
27ÉC (70ÉF-80ÉF)
Weastec (Steel Towers) 0.45 to 0.65 Ohms 7,000 to 15,800 Ohms
Coil Polarity
Engine Spark Plug Gap Thread Size
2.4L RC12YC5 0.048 TO 0.053 14mm (3/4 in.) reach
CABLE Maximum
Resistance
#1 & #4 4.2K ohms
#2 & #3 3.2K ohms
8D - 22 IGNITION SYSTEMNS

3.0L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
CAMSHAFT POSITION SENSOR............ 23
FIRING ORDERÐ3.0L.................... 23
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR............................. 23
REMOVAL AND INSTALLATION
CRANKSHAFT POSITION SENSOR.......... 25
ENGINE COOLANT TEMPERATURE SENSORÐ
3.0L................................. 25
IGNITION COILÐ3.OL.................... 24
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSORÐ3.0L........................ 24SPARK PLUG SERVICE................... 24
THROTTLE POSITION SENSOR............ 25
DISASSEMBLY AND ASSEMBLY
DISTRIBUTORÐ3.0L..................... 26
CLEANING AND INSPECTION
DISTRIBUTOR CAP...................... 26
DISTRIBUTOR ROTORÐ3.0L............... 27
SPECIFICATIONS
SPARK PLUG CABLE RESISTANCEÐ3.0L..... 27
SPARK PLUG........................... 27
TORQUE.............................. 27
DESCRIPTION AND OPERATION
FIRING ORDERÐ3.0L
MANIFOLD ABSOLUTE PRESSURE (MAP) SENSOR
The MAP sensor reacts to absolute pressure in the
intake manifold and provides an input voltage to the
Powertrain Control Module (PCM). As engine load
changes, manifold pressure varies. The changes in
engine load cause the MAP sensors resistance to
change. The change in MAP sensor resistance results
in a different input voltage to the PCM.
The input voltage level supplies the PCM with
information relating to ambient barometric pressure
during engine start-up (cranking) and engine load
while its operating. Based on MAP sensor voltage
and inputs from other sensors, the PCM adjusts
spark advance and the air-fuel mixture.
CAMSHAFT POSITION SENSOR
The PCM determines fuel injection synchronization
and cylinder identification from inputs provided by
the camshaft position sensor and crankshaft position
sensor. From the two inputs, the PCM determines
crankshaft position.
The 3.0L engine is equipped with a camshaft
driven mechanical distributor, containing a shaft
driven distributor rotor. The distributor is also
equipped with an internal camshaft position (fuel
sync) sensor (Fig. 1). This sensor provides fuel injec-
tion synchronization and cylinder identification to
the PCM.
The camshaft position sensor contains a hall effect
device callled a sync signal generator. This sync sig-
nal generator detects a rotating pulse ring (shutter)
on the distributor shaft. The pulse ring rotates 180
through the sync signal generator. Its signal 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.
When the leading edge of the shutter enters the
sync signal generator, the interruption of magnetic
field causes the voltage to switch high. This causes a
sync signal of approximately 5 volts.
When the trailing edge of the shutter leaves the
sync signal generator, the change of magnetic field
causes the sync signal voltage to switch low to 0
volts.
Since the shutter rotates at half crankshaft speed,
it may take 1 engine revolution during cranking for
the PCM to determine the position of piston number
6.
SPARK PLUG WIRE ROUTINGÐ3.0L ENGINE
NSIGNITION SYSTEM 8D - 23

REMOVAL AND INSTALLATION
SPARK PLUG SERVICE
When replacing the spark plugs and spark plug
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, cross ignition of the spark plugs orshort cir-
cuit the cables to ground.
Never Wire Brush Spark Plugs.The spark plug
insulator tip is harder than the bristles of wire
brushes. Bristles of wire brushes can leave a conduc-
tive, metallic film on the insulator which could lead
to conductive deposits. Conductive deposits can cause
spark plug failure and engine misfire. Use a jewelers
file to remove deposits from the electrode gap or use
a spark plug cleaning machine to clean spark plugs.
REMOVAL
Always remove cables by grasping at the boot,
rotating the boot 1/2 turn, and pulling straight back
in a steady motion.
(1) Prior to removing the spark plug, spray com-
pressed air around the spark plug hole and the area
around the spark plug.
(2) Remove the spark plug using a quality socket
with a foam insert.
(3) Inspect the spark plug condition. Refer to
Spark Plug Condition in this section.
INSTALLATION
(1) To avoid cross threading, start the spark plug
into the cylinder head by hand.
(2) Tighten spark plugs to 28 N´m (20 ft. lbs.)
torque.
(3) Install spark plug cables over spark plugs. A
click will be heard and felt when the cable properly
attaches to the spark plug.
IGNITION COILÐ3.OL
The ignition coil is located at the back of the
intake manifold (Fig. 2).
REMOVAL
(1) Remove air cleaner assembly.
(2) Disconnect ignition cable from coil.
(3) Disconnect wiring harness connector from coil.
(4) Remove coil mounting screws.
INSTALLATION
(1) Loosely install ignition coil on intake manifold.
Tighten the intake manifold fastener to 13 N´m (115
in. lbs.) torque. Tighten ignition coil bracket fasten-
ers to 10 N´m (96 in. lbs.) torque.
(2) Connect the wiring harness connector.
(3) Connect the coil to distributor ignition cable.
(4) Install the air cleaner assembly. Tighten the
air cleaner fasteners to 25 N´m (225 in. lbs.) torque.
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSORÐ3.0L
REMOVAL
(1) Remove vacuum hose and mounting screws
from manifold absolute pressure (MAP) sensor (Fig.
3).
(2) Disconnect electrical connector from sensor.
Remove sensor.
Fig. 1 Camshaft Position SensorÐ3.0L Engine
Fig. 2 Ignition CoilÐ3.0L Engine
8D - 24 IGNITION SYSTEMNS
DESCRIPTION AND OPERATION (Continued)

When replacing the distributor cap, transfer spark
plug wires from the original cap to the new cap one
at a time. Ensure that each wire is installed into the
tower of the new cap that corresponds to its tower
position in the original cap. Fully seat the wires into
the towers. If necessary, refer to the engine firing
order diagram.
Light scaling of the terminals can be cleaned with
a sharp knife. If the terminals are heavily scaled,
replace the distributor cap.
A cap that is greasy, dirty or has a powder-like
substance on the inside should be cleaned with asolution of warm water and a mild detergent. Scrub
the cap with a soft brush. Thoroughly rinse the cap
and dry it with a clean soft cloth.
DISTRIBUTOR ROTORÐ3.0L
Replace the rotor if it is cracked, the tip is exces-
sively burned or heavily scaled (Fig. 10).
SPECIFICATIONS
SPARK PLUG
TORQUE
DESCRIPTION......................TORQUE
Distributor Hold Down........14N´m(124 in. lbs.)
Ignition Coil Bracket..........10N´m(96in.lbs.)
Ignition Switch...............2N´m(17in.lbs.)
Spark Plugs.................28N´m(60in.lbs.)
SPARK PLUG CABLE RESISTANCEÐ3.0L
Fig. 9 Distributor Cap InspectionÐTypical
Fig. 10 Rotor InspectionÐTypical
Engine Spark Plug Gap Thread Size
3.0L RN11YC4 0.039 TO 0.044 14mm (3/4 in.) reach
CABLE Maximum
Resistance
#1 14.0K ohms
#2 10.4K ohms
#3 14.9K ohms
#4 11.5K ohms
#5 17.5K ohms
#6 10.3K ohms
Coil Lead 11.1K ohms
NSIGNITION SYSTEM 8D - 27
CLEANING AND INSPECTION (Continued)

3.3/3.8L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
FIRING ORDERÐ3.3/3.8L................. 28
REMOVAL AND INSTALLATION
CAMSHAFT POSITION SENSOR............ 31
CRANKSHAFT POSITION SENSOR.......... 30
ENGINE COOLANT TEMPERATURE SENSOR . . 32
IGNITION COIL......................... 30
KNOCK SENSORÐ3.3/3.8L................ 32
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR............................. 32SPARK PLUG CABLE SERVICEÐ3.3/3.8L
ENGINES............................ 28
SPARK PLUG SERVICEÐ3.3/3.8L ENGINES . . . 29
THROTTLE POSITION SENSOR............ 32
SPECIFICATIONS
IGNITION COIL......................... 33
SPARK PLUG CABLE RESISTANCEÐ3.3/3.8L . . 34
SPARK PLUG........................... 33
TORQUE.............................. 34
DESCRIPTION AND OPERATION
FIRING ORDERÐ3.3/3.8L
The firing order for 3.3L and 3.8L engines is 1-2-3-
4-5-6.
REMOVAL AND INSTALLATION
SPARK PLUG CABLE SERVICEÐ3.3/3.8L ENGINES
WARNING: The ignition cables should not be
removed while the engine is hot. This could cause
sever injury/burns and can cause damage to the
ignition cables.
The spark plug boot heat shield needs to be
installed correctly on the boot before being installed
on the engine (Fig. 1). If it is not installed correctly
engine misfire would occur.
Do not use pliers to pull the boot/heat shield
assembly from the spark plugs. This will damage the
shield assembly.
Spark plug boot heat shields must be replaced if
they are bent or damaged. It is extremely important
the shield is reinstalled correctly as shown. The bot-
tom of the spark plug heat shield must make contact
with the spark plug socket hex.
Firing OrderÐ3.3/3.8L
Fig. 1 Spark Plug Boot/Heat Shield Orientation
8D - 28 IGNITION SYSTEMNS