My multipla has just failed its MOT for this reason.

The light doesnt come on at all, even at start up.
The on board computor doesnt beep at me to tell me there is a problem with the ABS and all of the sensors were replaced last may, so i dont think there is a problem with them as such, just the light.

What do i need to be looking for? How do i fix this. I'd rather not have to take it into the garage if i can do it at home.

Thanks in advance.