DeVille, Eldorado, Seville 1999-2005

Ignition Control Module


Description & Operation

Each ignition control module (ICM) has the following circuits:

An ignition 1 voltage circuit
A chassis ground
An ignition control circuit for each cylinder
A low reference circuit

The PCM controls spark by pulsing the ignition control circuits to the ICM to trigger the coils and fire the spark plugs. The PCM and ICM are internally protected against shorts to power and ground on the ignition control circuits.

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 plugs are tipped with platinum for long wear and higher efficiency.