This is probably the standard VAG ATE Teves Mk 60 ABS/ESP brake pressure sensor fault. Three years ago VAG were charging £1800 to replace the entire ABS/ESP module. I found people who can do a fix for ...
They won't. If it's the regular ATE Teves Mk 60 brake pressure sensor failure, then the cheapest fix is by Sinspeed at £225 inc VAT, but excluding removal and refitting: www.sinspeed.co.uk. A ...