ABS Code and hub bearing

I had a diagnostic done and it came up with a code 154. The car care center said that I needed a r/f speed sensor and a r/f hub bearing. I knew that it had to be a speed sensor since this is the 2nd or 3rd time that I have had to replace a speed sensor. I have been to websites and looked in my Chilton book and no code 154 is there. How would I know if my bearing went bad? Thanks for all advice and help!