Ignition Control Module: Description and Operation

Ignition Module And Coils Replacement:

Ignition Schematic:

Ignition Synchronization:

Ignition Control:

PURPOSE

The ICM performs several functions:
^ It monitors the "ON-OFF" pulses produced by the two crankshaft and one camshaft position sensors.
^ It creates a 4X and 24X reference signal (4X REF HI and 24X CRANK) sent to the PCM for ignition control.
^ It creates a camshaft reference signal (1/2X CAM HI) sent to the PCM for fuel injection control.
^ It provides a ground reference (REF LO/CAM LO) to the PCM.
^ It provides a means for the PCM to control spark advance (BYPASS and IGNITION CONTROL) called IGNITION CONTROL MODE.
^ It provides a limited means of controlling spark advance without PCM input, called MODULE MODE.
^ The ICM is not repairable. When a module is replaced, the remaining components must be transferred to the new module.


LOCATION
The Ignition Control Module (ICM) is located on top of the rear camshaft cover