KW850 OBD2 CAN BUS Code Reader car engine fault code detector scannerBasic working principle: When the vehicle system fails, the fault (MIL) light or the check engine light is on, and the powertrain control module (PCM) stores the fault information in the memory, and the fault code is read out from the PCM through the device, according to the fault code. Prompt to quickly and accurately determine the nature and location of the fault. Check the relevant parts and component box lines in a targeted area to eliminate the