In two separate incidents (six months apart) and without warning, the Jeeps power steering suddenly failed. An indicator warning did come on but not prior to the failure in both instances. In both situations, I was attempting to exit very busy highways and little to no control over my vehicle. Some time after I had exited the highway, the Jeeps powering steering suddenly came back on. When I returned home, I had the vehicle inspected at the dealership both times and they were unable to determine any reason as to why the steering would have failed and without warning. Without an identifiable and fixable problem, I am very concerned about my personal safety and the safety of others on the roadway in the event that this should happen again without warning.