All petrol vehicle now days have coil packs in one design or another. The coil pack is deigned to create the ‘spark’ for the spark plugs. It is a electrical component which does not require servicing and has no set replacement schedule.
Coil packs can last for a long time, but they can fail like any electrical component. They live in the harsh environment of the engine bay on top of the engine where they are subject to a lot of heat. It is not uncommon for us mechanics to be called out to a vehicle running rough and misfiring with the cause being a failed coil pack.
Pictured is an example of a major failure from a Suzuki Grand Vitara. The failed coil is pictured with a new unit for comparison. This coil internally shorted out causing extreme heat and a small fire which damaged the leads and wiring.
This was repaired with the replacement parts – new coil and leads. A new connector plug was wired in and the vehicle was back to perfect operating condition.