Ignition Control Module
The Ignition Control Module (ICM) is located on top of rear camshaft cover. The ICM performs several functions:
- It monitors "ON-OFF" pulses produced by two crankshaft and one camshaft position sensors.
- It creates a 4X and 24X reference signal (4X REF HI and 24X CRANK) sent to PCM for ignition control.
- It creates a camshaft reference signal (1/2X CAM HI) sent to PCM for fuel injection control.
- It provides a ground reference (REF LO/CAM LO) to PCM.
- It provides a means for 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, remaining components must be transferred to new module.