mine was always good then suffered this problem too, for 9 months and 3k tut tut (dont tell anyone) light always on, coming back from blackpool msd , last 80 miles or so me pal drove , we then noticed the light was gone, abs working, not sure if msd fixed it without saying (im sure they would of) or the car liked my friend lolol pmsl . Also found a rear number plate light back in action too.