Ignition Control Module

The ICM performs the following functions:
- Powers the dual CKP sensor internal circuits
- Supplies the voltage signals that each respective hall effect pulses to ground in order to generate the 18X and 3X CKP sensor pulses
- Determines the correct ignition coil firing sequence based on how many 18X transitions occur during a 3X pulse. This coil sequencing occurs at startup. The ICM remembers the sequence and continues to trigger the coils, in both the module and IC modes.
- Cuts off the fuel delivery and the spark in order to prevent backfiring if reverse rotation is detected in the crankshaft
- Sends a crankshaft reference (fuel control) signal to the PCM (The PCM determines engine RPM from this signal.)