Saab Direct Ignition
It was first shown in 1985 and put into series production in the Saab 9000 in 1988. The system has been revised several times over the years. The ignition system together with the ignition coils form a single transformer oil filled cassette (or two cassettes in the case of a V6 engine) which is placed directly on the spark plugs, without the need for a distributor.
The system puts a low voltage over the spark plugs when they are not fired to measure ionization in the cylinders. The ionic current measurement is used to replace the ordinary cam phase sensor, knock sensor and misfire measurement function.
Direct Ignition Cassette
In the illustration to the right, the spark plugs are directly coupled to the "DIC" (or "IDM") which houses the ignition coils and electronics that measure cylinder ionization for use by the Trionic engine management system.