Operation CHARM: Car repair manuals for everyone.
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Ignition Control Module: Description and Operation

IGNITION CONTROL MODULE (ICM) AND IGNITION COILS

Each ignition coil is responsible for supplying secondary energy to a pair of spark plugs. The ICM converts the CKP sensor IAC voltage into a DC input to the PCM. The IC control signals output by the PCM are amplified by the ICM in order to fire each coil. The spark events are triggered by the ICM, but the module has no influence on spark timing. There are two ignition coil and ICM configurations that depend on engine type. The ignition coils and ICM are remotely mounted with conventional spark plug wires on the 2.2L engine.