Ignition Control Module: Description and Operation

ICM Location:

PURPOSE
The Ignition Control Module (ICM) assists the Powertrain Control Module (PCM) by operating the ignition coils that fire cylinders 4/7 and 5/10. The ICM responds to commands from the PCM and controls ignition coil dwell and ignition timing.


OPERATION
The PCM and ICM do not communicate directly. The PCM receives vehicle speed input directly and transmits dwell data to the ICM.

The PCM receives both crankshaft and camshaft position directly. The PCM supplies an 8 Volt referance signal to the crankshaft, camshaft position sensor, and ICM.