spitfire4

This light has been on for over a year. It doesn't seem to have effected anything. What is it? How do you turn this off?

sosh

This means that your brake assist is inoperative. Could be a number of reasons and that can be determined by a dealer or shop using the STAR diagnostic system. This is a VERY important safety item and it amazes me that you have let it go for a year. Thats downright negligent. Its important with an emergency quick stop to avoid hitting someone or something. Get it corrected ASAP