G201 - Brake Pressure Sensor 1 (DTC 01435)

However the mk60 works it would seem most repairers offer a lifetime warranty suggesting they know what causes the fault and how to permanently fix it!
I'd guess the failure is likely to be the pressure sensor/sensors.
They are under varying pressure virtually all the time the car is being driven, they still seem to last 15 - 20 years though!
As long as the replacement is of similar quality, then the lifetime warranty is pretty low risk I think.