System Description

With ignition switch at ON or START position, voltage is applied to ignition coil. Ignition coil consists of two coils. Ignition coils are located on rear of cylinder head. High tension leads go to each cylinder from ignition coil. Ignition coil fires two spark plugs on every power stroke (cylinder under compression and cylinder on exhaust stroke). Coil number one fires cylinders 1 and 4. Coil number two fires cylinders 2 and 3. Engine Control Module (ECM) provides a switching circuit to ground for energizing primary ignition coils. ECM uses crankshaft position sensor signal to time energizing of coil. When a primary ignition coil is energized and deenergized, secondary coil produces a high voltage spike across attached spark plugs.