Hi - resurrecting this thread as I'm suffering from the same problem and am getting conflicting advice.
When starting the engine, I get the "brake assist workshop" message and the image of the car on the slope. The ESP light also stays lit.
My local garage (an independent VW specialist) diagnosed a faulty brake pressure sensor as I expected, but have told me that they can't do the work as VW do not release the codes to programme any brake work????
Scouring old threads, some people seem to have had the entire ABS pump replaced at >?1500, whereas there is also advice that the sensor alone can be replaced at considerably less.
Reluctantly it looks like I'm stuck with having to go a main dealer for the work but I'd like to be clued up as to where I stand and what my options are. I'm on an 04 plate so no warranty unfortunately.
Any help much appreciated