Ignition Control Module: Description and Operation

The Ignition Control Module (ICM) receives engine position and speed information from the Crankshaft Position (CKP) sensor directing which ignition coil to fire, and controlling the turn ON/OFF times of the ignition coil to achieve the correct dwell and spark advance.
The ICM combines a Profile Ignition Pickup (PIP) signal and an Ignition Diagnostic Monitor (IDM) signal for use by the Powertrain Control Module (PCM) strategy.