I think that anybody who really wants to know how to access codes and interpret them can do it alreday. I am able to, and trust me, I am not mechanically or computer saavy. I just did an internet search and printed off the code information for each vehicle. On the SLS, I know the "trick" to getting the codes to display on the dash. For the Lade, I have a handheld programmer that also pulls them.
Don't get me wrong, I like Congress' idea here. I am just saying, I am not sure who it is going to help. Anybody who is that interested can do it themselves right now with just a little bit of research. However, I am only speaking to vehicles I have owned (GM). So, I guess I don't know how easy or hard it is, for example, to do the same thing with a Honda.