Ignition Coil: Description and Operation

IGNITION CONTROL MODULE (ICM)/COILS

There are 3 dual-tower ignition coils that are part of the ignition control module (ICM). The ICM contains coil driver circuits that command the coils to operate. The ICM has the following circuits:
- An ignition voltage circuit
- A ground circuit
- An IC 1 control circuit for the 1-4 ignition coil
- An IC 2 control circuit for the 2-5 ignition coil
- An IC 3 control circuit for the 3-6 ignition coil
- A low reference circuit

The ECM controls each dual-tower ignition coil by transmitting timing pulses on the IC control circuit to the ICM for the proper coil to enable a spark event.

The spark plugs are connected to each coil tower by spark plug wires. The spark plug wires conduct the spark energy from the coil to the spark plug. The spark plug electrode is tipped with platinum for long wear and higher efficiency.