Il shed my insight on these sensors as I deal with vehicle electronics a lot. The sensor on the servo is more of a safety device that has been used for years and often puts faults in stop/start systems and cruise controls systems, the restricted brake performance is the vehicles ecu reducing the limits of the abs pump/ module. It is worth buying a new sensor from the likes of eBay and fitting yourself. No coding required and system will reset after a certain amount of driving, sensor replacement will not involve any fluid loss so is a DIY job
