Neon L4-2.0L SOHC (1995)
Ignition Coil: Description and Operation
WARNING: The direct ignition system generates approximately 40,000 volts. Personal injury could result from contact with this system.
OPERATION
The coil pack consists of 2 coils molded together. The coil pack is mounted on a bracket, over the valve cover (Fig. 17). High tension leads route
to each cylinder from the coil.
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.
Coil number one fires cylinders 1 and 4.
Coil number two fires cylinders 2 and 3.
The PCM determines which of the coils to charge and fire at the correct time.
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 DESCRIPTION
Circuit A14 is a bus bar in the Power Distribution Center (PDC), and connects to battery voltage. The contact side of the Automatic Shut-Down (
ASD) relay connects circuit A14 and circuit A142. A 20 amp fuse in the PDC protects circuits A14 and A142.
Circuit A14 also supplies voltage to the coil side of the ASD relay. The Powertrain Control Module (PCM) controls the ground path circuit for the
coil side of the ASD relay on circuit K51. Circuit K51 connects to cavity 18 of the PCM connector.
Circuit A142 supplies voltage for the ignition coil pack through cavity 2 of the ignition coil connector. The coil pack consists of two individual
coils molded together. The PCM controls the ground circuit of each coil.
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Circuit K17 is the ground circuit for the ignition coil that fires spark plugs # 1 and # 4. Circuit K17 connects to cavity 21 of the PCM and
to cavity 3 of the ignition coil connector.
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Circuit K19 is the ground circuit for the ignition coil that fires spark plugs # 2 and # 3. Circuit K19 connects to cavity 1 of the PCM.
