Wow. Son of a B. Thanks for pointing that out. My brother used to have a 2004 Saab 9-3, I always knew it had that Trionic thing but I never really dug in to the details of what it was. I always thought it was just Saab's fancy BS marketing term for their engine control system kinda like what Bosch did with Motronic. I do like how ionic current sensing can determine combustion quality and also determine detonation for EACH cylinder. Even in 2020, I don't believe state of the art knock sensors can determine which cylinder had knock, so timing has to be retarded for all cylinders. That is a big plus in my book for ionic current feedback systems.The ionic sensing was invented and patented by Saab, It turned out to be dead reliable, in Car & Driver test reports the turbo Saabs always put down much better performance figures than competing turbo motors of greater advertised horsepower.
I believe this was by monitoring real time cylinder pressures there was no unwarranted preemptive timing pull back as in a knock sensor only motor.
BMW mentioned that the reason for going with ionic sensing was that in the range of 6000 to 8200 rpm the s85 had too much mechanical noise for reliable knock sensor operation.