Ignition Coil: Description and Operation
DESCRIPTION AND OPERATIONSix Tower Coil Pack (Stand Alone ICM Only):
The coil is turned ON (i.e. coil charging) by the Ignition Control Module (ICM), then turned OFF, firing two spark plugs at once. The spark plugs are paired so that as one spark plug fires on the compression stroke, the other spark plug fires on the exhaust stroke. The next time the coil is fired the situation is reversed. The next pair of spark plugs fire according to the engine firing order.