B4000 V6-4.0L SOHC (2005)
Ignition Coil Pack: Description and Operation
IGNITION COIL PACK
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Coil packs come in four tower, six tower vertical connector, and six tower horizontal connector models. Two adjacent coil towers share a common
coil and are called a matched pair. For six-tower coil pack (six cylinder) applications the matched pairs are 1 and 5, 2 and 6, and 3 and 4. For four
tower coil pack (four cylinder) applications the matched pairs are 1 and 4, and 2 and 3. When the coil is fired by the PCM, spark is delivered
through the matched pair towers to their respective spark plugs. The spark plugs are fired simultaneously and are paired so that as one 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.
