COP Ignition Systems
Manufacturers began omitting the distributor from earlier ignition systems to reduce cost and improve the performance of their engines. Soon after went the ignition wires. Ignition wires are expensive and wear. They were often considered a weak point in the ignition system. These two components are eliminated with COP ignition systems.
These ignition systems have many of the same problems inherent to coils and outside of a leaking boot, have omitted many problems inherent to distributors and wires. In earlier distributorless systems each coil produces spark for more than one cylinder. In a COP ignition system each coil supplies spark to only one cylinder. There is no waste spark. These systems require a crankshaft position sensor and most often a camshaft position sensor for ignition timing. The PCM calculates these signals and sends a signal directly to the individual coil which may or may not contain it's own IC module.
An advantage of this type of ignition system is coil saturation. Coil saturation is when the windings are saturated and capable of providing additional spark. This is important when accelerating or carrying a heavy load. When a coil loses saturation it will break up under a load or while power braking the vehicle. A scanner will quickly identify the culprit. The question mention excessive resistance in the primary and secondary circuits. These circuits are individual to each coil pack and would not effect all of the cylinders. A faulty PCM driver is the same. It only effects one cylinder. If the PCM were faulty or not receiving battery power there would be no spark at any of the cylinders.
