That’s interesting. My coil pack is also integrated, but it’s designed to fail independently. Maybe it’s the design of the coil, but not an inherent shortcoming of the system itself.

> One interesting tidbit is the coil packs run a bit of current over the plug when it's not sparking to measure ionization to determine engine conditions (i think mostly knock)

Didn’t know that. I knew that engine knock was measured with vibration sensors, crank position relative to other things and engine output measurements via load sensors (irregularity), but ionization measurement is new to me. Have any sources, so I can read more?

Yeah... no standard knock sensor, which is the normal way to do things, but it's much improved because a regular knock sensor on a 900 can't really tell, what cylinder is knocking (and no cylinder behaves the same, regardless of what you do), so on a distributed 900 with the Bosch systems, it'll hold boost back or (with ezk) retard knocking for a few full cycles.

With ionization it can determine -which- cylinder is knocking and adjust timing and fuel on that one specifically

Here's a good article

https://eeuroparts.com/blog/tech-corner-saab-trionic-and-ion...