ION L4-2.2L VIN F (2004)
Ignition Control Module: Description and Operation
IGNITION CONTROL MODULE (ICM) AND IGNITION COILS
Ignition Control Module (ICM) And Ignition Coils
Each ignition coil supplies secondary voltage to a pair of spark plugs. This is called a waste spark ignition system. The engine control module (ECM)
supplies a signal on each of the ignition control (IC) timing control circuits to the ignition control module (ICM). The ICM fires the correct ignition
coil at the correct time based on the signals. The ICM detects if cylinder 1 or cylinder 3 is on the compression stroke by sensing the secondary voltage
and polarity of each side of the ignition coil. The higher voltage is on the compressing cylinder. This is called compression sense ignition. The ICM
provides a synthesized cam signal to the ECM based on these inputs. The ECM uses the cam signal to synchronize fuel injection. This system consists
of the following circuits:
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The ignition 1 voltage circuit
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The ground circuit
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The camshaft position (CMP) sensor signal circuit
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The IC timing control for cylinders #1 and #4
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The IC timing control B circuit for cylinders #2 and #3
