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:
The life of ignition wire assemblies relies entirely on the ability of the owner and/or installer to install the wires correctly (particularly on engines designed to make it impossible to easily reach spark plugs), and the need to attach the wires to spark plugs and distributor/coils which are in good working order.