Hi all,
This thread was a life saver - had the same problem and was able to resolve it myself. STOP / START - Brake servo restricted requires the brake pressure booster sensor to be replaced.
TIP: I had to use a little WD40 on the orange O ring for the sensor to push and clip in.
I purchased mine from here:
https://www.ebay.co.uk/itm/234156424190?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=uI6ymBN1QH-&sssrc=4429486&ssuid=LlyWfVm0QjS&var=&widget_ver=artemis&media=COPY
Please see video for location on the Audi Q5 2019
20250328_134520.mp4