Chrysler Stratus RHD 1999 Electronic Service Manual page 971

14 - 42 FUEL SYSTEM
DESCRIPTION AND OPERATION (Continued)
OPERATION
The Automatic Shutdown (ASD) relay supplies bat-
tery voltage to the fuel injectors. The PCM controls
the ground path for each injector in sequence. By
switching the ground paths on and off, the PCM fine-
tunes injector pulse width. Injector pulse width
refers to the amount of time an injector operates.
The PCM determines injector synchronization from
the camshaft position sensor and crankshaft position
sensor inputs. The PCM grounds the ASD and fuel
pump relays when the ignition switch is initially
rotated to the run position . The PCM will de-ener-
gize the ASD and fuel relays if it does not receive the
camshaft position sensor and crankshaft position sen-
sor inputs.
The PCM energizes the injectors in a sequential
order during all engine operating conditions except
start-up. For the first injector pulse width during
start-up, all injectors are energized at the same time.
Once the PCM determines crankshaft position, it
begins energizing the injectors in sequence.
IGNITION COIL—PCM OUTPUT
DESCRIPTION
The coil assembly consists of independent coils
molded together (Fig. 32) or (Fig. 33) or (Fig. 34).
Fig. 32 Ignition Coil—2.0L
OPERATION
The coil assembly is mounted on the intake mani-
fold. High tension leads route to each cylinder from
the coil. The coil fires two spark plugs every power
stroke. One plug is the cylinder under compression,
the other cylinder fires on the exhaust stroke. The
PCM determines which of the coils to charge and fire
at the correct time.
The Automatic Shutdown (ASD) relay provides bat-
tery voltage to the ignition coil. The PCM provides a
ground contact (circuit) for energizing the coil. When
Fig. 33 Ignition Coil—2.4L
Fig. 34 Ignition Coil—2.5L
the PCM breaks the contact, the energy in the coil
primary transfers to the secondary causing the
spark. The PCM will de-energize the ASD relay if it
does not receive the crankshaft position sensor and
camshaft position sensor inputs. Refer to Automatic
Shutdown (ASD) Relay—PCM Output in this section
for relay operation.
MALFUNCTION INDICATOR (CHECK ENGINE)
LAMP—PCM OUTPUT
OPERATION
The PCM supplies the malfunction indicator (check
engine) lamp on/off signal to the instrument panel
through the CCD Bus. The CCD Bus is a communi-
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