Ignition Coil: Description and Operation

WARNING: THE ELECTRONIC IGNITION SYSTEM GENERATES APPROXIMATELY 40,000 VOLTS. PERSONAL INJURY COULD RESULT FROM CONTACT WITH THIS SYSTEM.

Fig. 7 Ignition Coil Pack (Right Side):

Fig. 8 Ignition Coil Pack (Left Side):

The electronic ignition system uses two epoxy filled coil packs mounted on a bracket at the rear of the engine. The coil pack on the left side, contains three separate coils and fires cylinders 1, 2, 3, 4, 6, and 7. The coil pack on the right side, contains two individual coils and fires cylinders 5, 8, 9, and 10. When one of the coils discharges, it fires two cylinders at the same time (one cylinder on its compression stroke, the other on its exhaust stroke).

The Auto Shutdown (ASD) relay provides battery voltage to the ignition coil. The PCM provides a ground contact (circuit) for energizing the coil. When the PCM breaks the contact, the energy in the coil primary transfers to the secondary causing the spark. The PCM will de-energize the ASD relay if it does not receive the crankshaft position sensor and camshaft position sensor inputs.