COP Ignition Systems

Manufacturer's 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 on coil over plug (COP) ignition systems.

COP  Ignition System No Spark

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 usually a camshaft position sensor for ignition timing. The PCM calculates these signals and sends a signal directly to the cylinder's individual coil, which may or may not contain its own IC module.

The question mentions excessive resistance in the primary and secondary circuits. These circuits are individual to each coil and would not affect all of the cylinders. A faulty PCM driver is the same, because it affects only one cylinder. If the PCM is not receiving power, there would be no spark at any of the cylinders.