Diesel Data: Automotive Repair

Ignition Coil: Description and Operation

IGNITION COILS

Each ignition coil has an ignition 1 feed and a ground. The PCM supplies a low reference and an ignition control (IC) circuit. Each ignition coil contains a solid state driver module as the primary element. The PCM signals the coil driver to initiate a firing event by applying the IC circuit voltage for the appropriate time, or dwell. When the voltage is removed the coil fires the spark plug. 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 platinum for long life and efficiency.