Fault diagnosis system for i.c. engine exhaust gas feedback device

摘要

The fault diagnosis system has the ignition timing point (ZZP) for the engine advanced until a min. engine knock regulation (KRT) is attained, when the exhaust gas feedback device (AGR), is active and the engine is operated with stationary operating characteristics. The ignition timing point is then held constant while the exhaust gas feedback rate (AGRR) is reduced, with detection of a variation in the knock frequency or the knock regulation.The indication of a fault in the exhaust gas feedback device is provided when no variation in the knock frequency or the knock regulation is detected.