Ignition Coil: Description and Operation

IGNITION COILS

Each ignition coil has an ignition 1 voltage feed and a ground. The engine control module (ECM) supplies a low reference and an ignition control (IC) circuit. Each ignition coil contains a solid state driver module. The ECM will command the IC circuit ON, this allows the current to flow through the primary coil windings for the appropriate time or dwell. When the ECM commands the IC circuit OFF, this will interrupt current flow through the primary coil windings. The magnetic field created by the primary coil windings will collapse across the secondary coil windings, which induces a high voltage across the spark plug electrodes. The coils are current limited to prevent overloading if the IC current is held high too long. The spark plugs are connected to their respective coils by a short secondary wire. The spark plugs are tipped with iridium for long life and efficiency.