Ignition Control Module: Description and Operation
DESCRIPTION AND OPERATIONIgnition Control Module (ICM):
The Ignition Control Module (ICM) receives crankshaft position and speed information from the Crankshaft Position (CKP) sensor, and desired spark advance information from the Powertrain Control Module (PCM). It uses this information to direct which ignition coil to fire, and controls the turn ON and turn OFF of that ignition coil to achieve the correct dwell and spark advance. The ICM also synthesizes a Profile Ignition Pickup (PIP) signal and an Ignition Diagnostic Monitor (IDM) signal for use by the PCM. It then sends information on system failures through the IDM signal to the powertrain control module which stores information for use during diagnostic test mode. The IDM also provides the signal to drive the tachometer.