BMW 318ci convertible comes up with eci reading.

BMW 318ci convertible comes up with eci reading on dash and then gone off then picture of engine (exhaust emission values have deteriorated a garage did diagnostics comes up with 285A DME Variable valve gear monitoring.
2865 dme variable valve gear power limitation in limp mode
18 water valuve
17 auxillary water pump

The car drives ok at the moment but I need some advice on this as one garage says its an oversensitive switch another says take it to bmw and it is a bmw fault that they have had in the past so they are at fault with regards to repairs I am looking for some advice on what to do next

your views would be greatly appreciated from a woman driver who has never had her own car until relatively recently