Ignition Control Module: Description and Operation
PURPOSEThe Transistorized Ignition Module 3-pin (TI3) type relays spark control signals from the Powertrain Control Module (PCM) to the ignition coil. The module controls current through the coil primary windings.
OPERATION
The Ignition Control Module (ICM) receives a signal from the PCM, and opens and closes the ignition coil primary circuit to fire the spark plugs.