Hi,

I've got a 2006 A6 with only 40k on the clock. It's been well looked after and recently had a minor service done on from a Audi specialist. All was well until i gave my car in for a MOT today. I left my car with the garage in the morning and picked it up in the evening. It passed the MOT but on the advisory it said engine management light on.
I know that this light has never been on in my car and as I do a lot of driving I make sure I check everything, plus how could I miss the yellow light on the dash. Anyway, the garage said it must have been there before the MOT and the first thing they do is check for errors, I know it was not but they are not listening to me.
I doubt if anything in the MOT could cause this or could it?.
I'm not sure what to do, can I say anything to the garage?. What could it be?

Any help will be appreciated.

Thanks