Chrysler 1998 Voyager Service Manual page 321

NS
DESCRIPTION AND OPERATION
CAMSHAFT POSITION SENSOR . . . . . . . . . . . . 23
FIRING ORDER—3.0L . . . . . . . . . . . . . . . . . . . . 23
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
REMOVAL AND INSTALLATION
CRANKSHAFT POSITION SENSOR . . . . . . . . . . 25
ENGINE COOLANT TEMPERATURE SENSOR—
3.0L . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
IGNITION COIL—3.OL . . . . . . . . . . . . . . . . . . . . 24
MANIFOLD ABSOLUTE PRESSURE (MAP)
SENSOR—3.0L . . . . . . . . . . . . . . . . . . . . . . . . 24
DESCRIPTION AND OPERATION
FIRING ORDER—3.0L
SPARK PLUG WIRE ROUTING—3.0L ENGINE
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.
3.0L ENGINE
INDEX
page
SPARK PLUG SERVICE . . . . . . . . . . . . . . . . . . . 24
THROTTLE POSITION SENSOR . . . . . . . . . . . . 25
DISASSEMBLY AND ASSEMBLY
DISTRIBUTOR—3.0L . . . . . . . . . . . . . . . . . . . . . 26
CLEANING AND INSPECTION
DISTRIBUTOR CAP . . . . . . . . . . . . . . . . . . . . . . 26
DISTRIBUTOR ROTOR—3.0L . . . . . . . . . . . . . . . 27
SPECIFICATIONS
SPARK PLUG CABLE RESISTANCE—3.0L . . . . . 27
SPARK PLUG . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
TORQUE . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
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.
IGNITION SYSTEM 8D - 23
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