Modern cars are basically rolling computer networks. When you only use a basic...

https://sierra-wiki.win/index.php/The_Future_of_Diagnostics:_Why_EVs_and_ADAS_Change_Everything_for_Your_Shop

Modern cars are basically rolling computer networks. When you only use a basic OBD reader, you are just looking at a tiny fraction of the puzzle. Professional diagnostic software lets you talk to every ECU in the vehicle