Ignition Control Module (ICM)
The ignition control module is mounted to the ignition coil. See Fig 1 . Based on control system inputs, the ECU triggers the ignition coil via the ignition control module. The ECU is able to advance or retard ignition timing by controlling the ignition coil through the ignition control module.
The ICM consists of a solid state ignition circuit, an integrated ignition circuit and an integrated ignition coil that can be removed and serviced separately if necessary.
The ECU provides an input signal to the ICM. The ICM has only two outputs:
- Tach signal to the tachometer and diagnostic connector
- High voltage from the coil to the distributor cap