Like Alan said, is for the dynamic cruise control range, but before you use it you'd better read the manual. I'm assuming your Toyota salesman didn't tell you much about the radar in your high tech new car. You likely will not have had anything like this before.
Actually for those who don't know, early adaptive cruise systems did use lasers. However it didn't work in rain or snow and it was also affected by the reflectivity (or lack thereof) of the vehicle it was tracking. Also the laser box had to be out front on the grille, it couldn't be hidden behind a $500 emblem like radar sensors can
As with all things Prius, it really helps to read the manual, however bloated it may seem. There are plenty of parts you can skip over (I'm looking at you, Tire Information...), but I, for one, like to know how to operate all of the gewgaws and whirligigs...
Thanks. But I press it. Nothing changes/ nothing shows up. Is it possible I got a defective bottom? I mean when you press it, it suppose to change something right?
Yuki, you have to be using the the cruise control with car in forward motion and a target speed set BEFORE you press the button for it to work. I'm not gonna lead you by the nose through extracts from the manual, but strongly recommend you actually read it for yourself. There are important safety notes in there that Toyota want you to be aware of, and I'm not qualified to teach them to you.
I only need to know tire size, tread depth, and pressure. Everything else is 'nice to know', but not essential...
