Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)

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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.