Now im speaking from memory however, in my 190 (at the time) you had to go to the back of the seat and go the the very bottom and there was 3 or 4 screws holding the back plate on,, once those are removed then you can slide the panel down and it shows you everything thats goin on inside the seat, it may be a broken clip or something stripped... but once you getthe back panel off it should tell the story..