Ignition Control Module: Description and Operation
IGNITION CONTROL MODULEThe Ignition Control Module (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) call 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.