1996 CHRYSLER VOYAGER Service Manual

IGNITION TIMING PROCEDURE
The 2.4, 3.0, and 3.3/3.8L engines use a fixed igni-
tion system. Basic ignition timing is not adjustable.The Powertrain Control Module (PCM) regulates
ignition timing.
Fig. 34 PDC Rear Bracket
Fig. 35 PCM 40-Way Connectors
Fig. 36 PCM Removal/Installation
NSIGNITION SYSTEM 8D - 15
SERVICE PROCEDURES (Continued)

2.4L ENGINE
INDEX
page page
DESCRIPTION AND OPERATION
CAMSHAFT POSITION SENSOR............ 17
CRANKSHAFT POSITION SENSOR.......... 16
FIRING ORDERÐ2.4L.................... 16
INTAKE AIR TEMPERATURE SENSORÐ2.4L . . . 17
REMOVAL AND INSTALLATION
CAMSHAFT POSITION SENSOR............ 19
CRANKSHAFT POSITION SENSOR.......... 19
ENGINE COOLANT TEMPERATURE SENSORÐ
2.4L................................. 20
IGNITION COILÐ2.4L..................... 18
INTAKE AIR TEMPERATURE SENSORÐ2.4L . . . 21KNOCK SENSORÐ2.4L................... 21
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSORÐ2.4/3.3/3.8L.................. 20
SPARK PLUG CABLE SERVICEÐ2.4L........ 18
SPARK PLUG SERVICE................... 18
THROTTLE POSITION SENSOR............ 20
SPECIFICATIONS
IGNITION COIL......................... 22
SPARK PLUG CABLE RESISTANCEÐ2.4L..... 22
SPARK PLUG........................... 22
TORQUE.............................. 22
DESCRIPTION AND OPERATION
FIRING ORDERÐ2.4L
CRANKSHAFT POSITION SENSOR
The PCM determines what cylinder to fire from the
crankshaft position sensor input and the camshaft
position sensor input. The second crankshaft counter-
weight has machined into it two sets of four timing
reference notches and a 60 degree signature notch
(Fig. 1). From the crankshaft position sensor input
the PCM determines engine speed and crankshaft
angle (position).The notches generate pulses from high to low in
the crankshaft position sensor output voltage. When
a metal portion of the counterweight aligns with the
crankshaft position sensor, the sensor output voltage
goes low (less than 0.3 volts). When a notch aligns
with the sensor, voltage switches high (5.0 volts). As
a group of notches pass under the sensor, the output
voltage switches from low (metal) to high (notch)
then back to low.
If available, an oscilloscope can display the square
wave patterns of each voltage pulse. From the width
of the output voltage pulses, the PCM calculates
engine speed. The width of the pulses represent the
amount of time the output voltage stays high before
switching back to low. The period of time the sensor
output voltage stays high before switching back to
low is referred to as pulse width. The faster the
FIRING ORDERÐ2.4L
Fig. 1 Timing Reference Notches
8D - 16 IGNITION SYSTEMNS

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)