Internal combustion engine's e.g. petrol engine, functional parameter e.g. injection moment, or defect e.g. default equipment, diagnosing method for motor vehicle, involves utilizing electrical signal to diagnose functional state of engine

摘要

The method involves capturing sound waves of an internal combustion engine (2) of a motor vehicle (1) using a ultrasonic sound receiver (7) such as microphone, of a sensor unit (5), where the sound waves comprises air waves and structure-borne noises. The sound waves of the internal combustion engine are converted into an electrical signal using the sound receiver. The electrical signal is utilized for diagnosing a functional state of the internal combustion engine.