i have a 1999 bmw 323i and the brake lights keep coming on. i took it up to bmw and they replaced the brake switch and it stopped doing it, then the next day it came back on. i put a new gauge cluster in and it didnt come on for about a week. it started doing it again today and my check engine light is on and the code is p1520 with is "b" camshaft actuntor bank 1. does anyone no what this is. i'm new with bmws so any help would help me not alot. i just want the brakes to work right . thanks