System check question

[1995E]

In my system check, it lists brakes as OK,

By OK, does it mean the wear on my pads are okay?
If so how does it know my brakes are actually okay? There doesn't seem to be any wear level indicators in the caliper or rotors so how does it know?

 

[LukerDooker]

It has no idea.
Its likely by miles and or time passed since last reset.
At an oil change the oil life and sometimes the system status is reset, and it just knows when the next maintenance interval is approaching.

For brakes there may be a connected sensor for ABS, something wired to the system that is simple. It don't know squat about the pads and wear.