Chrysler Concorde 1993 Service Manual page 263

keeps track of crankshaft rotation and identifies each
cylinder by the pulses generated by the notches on
the camshaft sprocket. Four crankshaft pulses follow
each group of camshaft pulses.
When the PCM receives two cam pulses followed
by the long flat spot on the camshaft sprocket, it
knows that the crankshaft timing marks for cylinder
one are next (on driveplate). When the PCM receives
one camshaft pulse after the long flat spot on the
sprocket, cylinder number two crankshaft timing
marks are next. After 3 camshaft pulses, the PCM
knows cylinder four crankshaft timing marks follow.
One camshaft pulse after the three pulses indicates
cylinder five. The two camshaft pulses after cylinder
5 signals cylinder six (Fig. 13 or Fig. 14). The PCM
can synchronize on cylinders 1 or 4.
When metal aligns with the sensor, voltage goes
low (less than 0.3 volts). When a notch aligns with
the sensor, voltage spikes high (5.0 volts). As a group
of notches pass under the sensor, the voltage
switches from low (metal) to high (notch) then back
to low. The number of notches determine the amount
of pulses. If available, an oscilloscope can display the
square wave patterns of each timing event.
Top dead center (TDC) does not occur when notches
on the camshaft sprocket pass below the cylinder.
TDC occurs after the camshaft pulse (or pulses) and
after the 4 crankshaft pulses associated with the par-
ticular cylinder. The arrows and cylinder call outs on
Figures 13 and 14 represent which cylinder the flat
spot and notches identify, they do not indicate TDC
position.
Fig. 11 Camshaft Position Sensor—3.3L Engine
Fig. 12 Camshaft Position Sensor—3.5L Engine
IGNITION SYSTEMS
Fig. 13 Camshaft Sprocket—3.3L Engine
Fig. 14 Camshaft Sprocket—3.5L Engine
The camshaft position sensor is mounted in the
front of the timing case cover (Fig. 15 or Fig. 16).
CHARGE AIR TEMPERATURE SENSOR
The 3.5L engine uses a charge air temperature sen-
sor, the 3.3L engine does not. The sensor threads into
the intake manifold plenum and measures air tem-
perature (Fig. 17). The sensor provides one of the in-
puts the PCM monitors when it adjust injector pulse
width and spark advance.
CRANKSHAFT POSITION SENSOR
The crankshaft position sensor detects slots cut
into the transmission driveplate extension. There are
3 sets of slots. Each set contains 4 slots, for a total of
12 slots (Fig. 18). Basic timing is set by the position
of the last slot in each group. Once the powertrain
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