The paper describes the problem of the combustion process diagnostics dedicated for CI engines with direct injection of HDV vehicles in the aspect of misfire detection monitor application for OBD and EOBD systems. The monitor is based on the vibroacoustic signal utilization. Because of that, frequency method and the method of time-frequency parameterization map a(t,f) of vibration accelerations generated by combustion engine were used. The above article is directed to get a diagnostic monitor that would detect faults and incorrect runs in the combustion process (including also its lack) in the real time with the help of vibration accelerations estimators. Point estimators of the process and research stages and conditions are presented. The signal analyses and limits of a method use, criteria of the process qualification and its accuracy were also write down. Diagnostic algorithms of misfire detection and possibility of its practical use in the contemporary vehicle sources of a drive and future OBD III systems, advantages of a presented methods comparing with present solutions and their importance in the of combustion steering and control strategy of the engine are described as well.