New fault indication has started on my Mk6 Golf CC GT (2012, 29K miles). The indicator showing DSG mode (D, S or P) and gear number, flashes alternately with a spanner symbol. This happens after the engine has fully warmed up and doesn't go away until it has fully cooled down after stopping the engine. It happens in any driving mode and regardless of load on the engine. No info on this sort of warning in the handbook and VW dealer seems clueless - "Book it in and we'll have a look at it." Does anyone have any idea what the problem might be and what the solution is?