Modern cars are basically rolling computer networks. Your basic OBD reader just...

https://uniform-wiki.win/index.php/My_Scan_Tool_Cannot_Do_Service_Resets:_What_Now%3F

Modern cars are basically rolling computer networks. Your basic OBD reader just gives you a surface-level fault code, but that barely scratches the surface. Professional diagnostic software lets you talk to every ECU in the vehicle