I had exactly the same issue as all the rest on this thread.
I have Audi A5 2.0 Diesel 67 plate coupe. I read the forum, rang the dealer and asked how much they said £165 to diagnose , yeah right, so i ordered the part Photos attached, £79.20 collected it within the hour, it take less that 5 minutes yes FIVE minutes to complete the job. All warnings gone, brakes feel correct again. SS showed up so switched off and re-started and that also was gone.
Saved at least £95 from the diag alone.
It is so simple it's embarrassing.
Thank you to Simon Ryder for first showing photos.
Note the yellow end is just a terminal protector nothing more.
The bag is what it came in with barcode number and the dash is what was bing displayed this morning.
Thank you.