Dodge RAM TRUCK 1500 1995 Service Manual page 377

8D ~ 4 IGNITION SYSTEMS — — — — — — — B R
SPARK
P L U G
CABLE
L O O M
W I R I N G
I M 1
^ N H A R N E S S
J 9 3 ] V ^ \
C O N N E C T O R \
EGR > TUBE MOUNTING
TUBE / f BOLTS (2)
Fig. 6 Crankshaft Position Sensor—3.9L V-6 or
5.2/5.9L V-8 Engines—Typical
CRANKSHAFT
POSITION
SENSOR
FLYWHEEL
NOTCHES'
J9314-89
Fig. 7 Sensor Operation—3.9L
V-6 Engine
For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group.
For removal and installation of this sensor, refer to
the Component Removal/Installation section of this
group.
SENSOR
OPERATION—^5.2i/5.9L ¥-8
ENGINES
On 5.2L and 5.9L V-8 engines, the flywheel/drive
plate has 8 single notches, spaced every 45 degrees,
at its outer edge (Fig. 8).
CRANKSHAFT
P O S I T I O N
S E N S O R
N O T C H E S
FLYWHEEL
J9314-88
Fig. 8 Sensor Operation—5.2L/5.9L V-8 Engines
The notches cause a pulse to be generated when
they pass under the sensor. The pulses are the input
to the PCM. For each engine revolution, there are 8
pulses generated on V-8 engines.
The engine will not operate if the PCM does not re­
ceive a crankshaft position sensor input.
For component testing, refer to the Diagnostics/Ser­
vice Procedures section of this group.
For removal and installation of this component, re­
fer to the Component Removal/Installation section of
this group.
CRANKSHAFT POSITION SENSOR—8.0L V-10
ENGINE
The crankshaft position sensor is located on the
right-lower side of the cylinder block, forward of the
right engine mount, just above the oil pan rail (Fig.
9).
SENSOR OPERATION—8»m
lf-10
ENGINE
The crankshaft position sensor detects notches ma­
chined into the middle of the crankshaft (Fig. 10).
There are five sets of notches. Each set contains
two notches. Basic ignition timing is determined by
the position of the last notch in each set of notches.
Once the powertrain control module (PCM) senses
the last notch, it will determine crankshaft position
(which piston will next be at Top Dead Center). An
input from the camshaft position sensor is also
needed. It may take the module up to one complete
engine revolution to determine crankshaft position
during engine cranking.
The PCM uses the signal from the camshaft posi­
tion sensor to determine fuel injector sequence. Once