Automatic RON Switch

The knock sensor system has an automatic Research Octane Number (RON) switch. If ignition pinging is persistent, the RON switch will help the knock sensor by performing a pre-control ignition adjustment. This is accomplished using the knock sensor adaptation values, ignition timing on all cylinders, and number of times ignition timing was adjusted given a specific engine load and speed. Depending on which threshold was exceeded, RON value is adjusted by one or several stages. The adjustment value is used until the engine is turned off. At engine start, the RON correction stored using the Hand Held Tester (HHT) is used before any further adjustments are made.