They check codes and depending why your light is on. Did you check coolant and belt Mine came on my truck cause a pully was loose creating squeaking Could be a variety of things buy a cheap code reader.. Its worth it
Sorry, I do not have that data for you.
All they do is put a guage on the box underneath the steering column and it will tell them what's wrong with the car if it's something important you will have to get it fixed or the light will come back on. The cost is nothing
Free service, as long as you have the obd hook up , which the Prius should
Thanks! Your answer is awaiting moderation.