Ignition Coil: Description and Operation

Fig.4 Exploded View Of On-Plug Ignition Coils.:

The coil assembly consists of coil body with an integral two pin plug, a central electrode and extension housing. Problems with the ignition coils are detected using two tests on signals checking the coil current which analyze the current monitor signal when ignition coils are turned on during normal engine running. The coils are monitored to detect either non or early activation.