Got a Mercedes C250 2015 model, went in for a service on 25 November, on the 11 December Amber engine management light came on, took it to a local garage today who gave me the following fault codes: P13DF-09, P1BC3-00, P229F-09 and P229F-91 he thinks its to do with the Ad-blu but his system won't let him get any further, have rung Mercedes who can't fit it in till 4 January. Anyone any ideas what it may be and how much I could be looking at to get it right and if I'm ok to keep driving it.