Understanding the appropriate procedure and diagnosis codes for a particular study question is an important part of analyzing Medicare data. These codes are very specific and can change from year to year as new codes are added and others are discontinued.
There is no wear-out factor in the coil itself other than thermal cycling and the damage it may cause. Boots and wires do age, resulting in reduced insulation value over time. The key to correct ignition system diagnosis is to understand the details of how the system you are working on really functions. PAGE:
Coils seldom fail, but when they do they can't provide voltage to the spark plug(s). On a single coil ignition system, a coil failure will cause the engine to quit and prevent it from starting. On a multi-coil DIS or COP ignition system, it will cause a misfire in only the cylinders supplied by the bad coil.