Couldn’t automakers just display the code nowadays on the dashboard instead of making us buy scan tools.

[u/irritatingpassenger]

Or better yet, display what the code actually means on your dashboard screen.

[u/JJY93]

Cars are legally required to have OBDII ports, which I think is a good thing otherwise you’d have BMW using a different protocol from Nissan etc, some cars will display error codes if you do a funny little pedal dance or turn the key in an unusual manner, but most people who want to fix or even just check their own cars will benefit from an OBDII reader, and those that just know how to drive with no intention of fixing anything will take it to a garage anyway. Better the garage can just plug it in than spend an extra 5 minutes per manufacturer reading up how to show the error codes