Comprehensive system for diagnostics of EMU-trains sections COMPACS®-EXPRESS-TR3 is designed for a comprehensive automatic health evaluation of the most compound equipment, subjected to operational wear and failures of EMU-trains sections (wheel motor units; pantographs; compressed-air and electric-pneumatic brake system; electric control circuits; high-voltage power circuits; heating and auxiliary electric circuits) within current repairs of a large amount. According to the defined equipment classes, the system includes seven diagnostic subsystems, interacting as one. br br The system structure and components together with the adopted layout allow to carry out the comprehensive diagnostics of EMU-trains sections of 15 different AC and DC series on the single software-and-hardware.