Ignition Control Module: Description and Operation

IGNITION COIL/ICM ASSEMBLY
Each ignition control module has the following circuits:
- An ignition voltage circuit
- A ground
- An ignition control (IC) circuit
- A low reference circuit

The PCM controls the individual coils by transmitting timing pulses on the IC circuit of each ignition coil/module to enable a spark event.

The spark plugs are connected to each coil by a short boot. The boot contains a spring that conducts the spark energy from the coil to the spark plug. The spark plug electrode is tipped with platinum for long wear and higher efficiency.