ECM is activated by power supply. Signals from several sensors, such as CKPS and APS, is inputted to ECM. Comparing inputted signals with control LOGIC saved at micro controller and EEPROM, ECM controls engine as actuating injectors, solenoids and relays. To guarantee accurate control, ECM performs SELF TEST, DIAGNOSIS of several sensors and actuators. And if serious trouble which affects vehicle performance occurs, ECM sets DTCs. At certain cases, ECM shuts down whole systems in order to prevent dangerous situation due to incorrect control.

P1145 will be set when fuel cut is not performed, that is ECM still controls fuel injection through the injector although accelerator pedal is off or actual engine RPM is higher than 320RPM which is target RPM controlled by ECM for more than 0.8sec. In this case, Drive stage for injectors in ECM is failure to controlling the power supply cut.