Grand Caravan AWD V6-229 3.8L VIN L MFI (1997)
Ignition Coil: Description and Operation
Fig 4 Coil Pack
WARNING: The direct ignition system generates approximately 40,000 volts. Personal injury could result from contact with this system.
CONSTRUCTION
The ignition coil assembly consists of independent coils molded together (Fig. 4). The coil assembly is mounted on the intake manifold. Spark
plug cables route to each cylinder from the coil.
OPERATION
The coil fires two spark plugs every power stroke.
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One plug is the cylinder under compression.
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The other cylinder fires on the exhaust stroke.
The Powertrain Control Module (PCM) determines which of the coils to charge and fire at the correct time.
Coil 1 fires cylinders 1 and 4, coil 2 fires cylinders 2 and 5 and coil 3 fires cylinders 3 and 6.
The Auto Shutdown (ASD) relay provides battery voltage to the ignition coil. The PCM provides a ground contact (circuit) for energizing the coil.
When 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.
CIRCUIT OPERATION
The ignition coils are molded together. Each coil fires two spark plugs at one time. One cylinder is beginning its compression stroke, the other its
exhaust stroke. Refer to Ignition System, for system operation.
When the Automatic Shut Down (ASD) relay contacts CLOSE, they connect circuit #4 to circuit A142. Circuit A142 supplies battery voltage to
the ignition coils. The Powertrain Control Module (PCM) controls the ground circuit of each coil.
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Circuit K19 is the ground circuit for the ignition coil that fires spark plugs one and four. Circuit K19 connects to cavity 11 of the PCM.
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Circuit K17 is the ground circuit for the ignition coil that fires spark plugs two and five. Circuit K17 connects to cavity 3 of the PCM.
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Circuit K18 is the ground circuit for the ignition coil that fires spark plugs three and six. Circuit K18 connects to cavity 2 of the PCM.
Helpful Information
Circuit A142 splices to supply voltage to the fuel injectors, generator field, upstream heated oxygen sensor and downstream heated oxygen sensor.
Circuit A142 also connects to cavity 6 of the PCM.
