Today’s cars are rolling computer networks. You can’t fix a modern vehicle by...

https://www.focus2move.com/why-diagnostic-software-has-become-essential-for-modern-vehicle-repairs/

Today’s cars are rolling computer networks. You can’t fix a modern vehicle by just guessing because the ECUs control everything from fuel trims to door locks. Basic OBD readers only give you a surface-level fault code, which rarely tells the whole story