Knock Sensor: Description and Operation

Saab Trionic's ignition system comprises an ignition discharge module with four ignition coils, one for each spark plug. The ignition system is capacitive. The spark plugs are used as sensors to detect combustion and knocking. This means that neither camshaft sensor not knock sensor is required. The function provides an efficient means of detecting misfiring.

Only the Motronic 2.10.3 (B204I) uses a camshaft position sensor. This ignition system was not imported for the US market.