Coil-on-Plug — Ignition kV

What it tells you

The COP waveform reveals the firing-line voltage and the burn line that follows. Tall firing lines hint at a lean cylinder or worn plug; a short burn time points to fouling. None of this surfaces on an OBD misfire counter alone.

Healthy vs fault

Toggle Fault overlay on the scope above to drop the faulty capture over the healthy one. Seeing both traces on the same graticule is how you train your eye for the difference — the deviation that names the fault.

Symptoms this catches

• ▸misfire
• ▸rough idle
• ▸lean
• ▸spark plug
• ▸ignition fault

Watch the walkthrough