Power Steering Light On problems of the 2014 Hyundai Tucson

I loose power steering. The steering wheel is so loose you have to hang onto to keep the car on the road. It happens frequently when driving over a stretch of road that is been patched ( and there are many stretches like that in NJ) but that is not always the case. There is no clear pattern to this situation. Generally it happens once and then not again for a couple of days - then the lights on the dash come indicating issues with the steering, tire pressure and engine malfunction. First go around was sept. 2014 @ 6,800 miles. It was taken into Hyundai - the test drove it for a couple of days until the problem occurred for them. The steering column (upper assembly) was replaced. A year goes by (sept. 2015) and it starts again @14,800 miles. Same procedure as last year - pick vehicle up after 9 days - 2 hours later, same thing, no steering all the lights come. This time the cleaned grounds. One week later same situation . Driving this vehicle is extremely tense, many times I have to pull off the road and wait for others to pass. And hope that is corrects itself, which it does sometimes but for how long I never know.