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Ignition Control Module: Description and Operation

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PURPOSE
Ignition control module is an engine control module (ECM) controlled switching device that controls the primary circuit of the ignition coil.

OPERATION
The ECM determines optimum ignition timing from various inputs and transmits a primary current OFF signal to the ignition control module. The ignition control module interrupts the current flow through the ignition coil's primary circuit which results in a secondary spark discharge from the coil.