Hydraulic Power Assist Steering System problems of the 2002 Volkswagen Jetta

The power assist for this tdi vehicle has failed multiple times under several different circumstances. Most often, it occurs when applying the cruise control at speeds of less than 70mph and also when having to rapidly decellerate or move along with city related traffic. Most often, the check engine light comes on, but by the time it does, I already know there is a problem. I have no passing gear, and to accelerate from a stop to 60 mph takes a minute or more. Typically, when the problem occurs, if I stop the vehicle, turn it off, and crank it again, the problem is resolved until the circumstances which bring about the problem are re-enacted. It will usually take several cycles of the engine being cranked and turned off before the check engine light will turn itself off. I purchased the vehicle used with about 35,000 miles on it and the problem occurred about 100 miles from the dealership. After having the vehicle in for repeated repairs, I've since come to learn that similar problems were occurring with the vehicle prior to my purchasing it (were not disclosed at purchase), according to service records.