general problems of the 2011 Hyundai Azera

On 03/02/16 - I was driving on george 400 expressway and I slowed down to take an exit and without any warning my vehicle completely lost power; the steering wheel became stiff and the dashboard lights came on. I had to roll to the shoulder and turn my flashers on. I put the vehicle in neutral and it started back up. I was able to drive to a safe location. This also occurred approximately a year ago while I was driving on a freeway (I-285). I took it to the Hyundai dealership and they could not find anything explanation as to why it lost power. This concerns me because I drive a lot on the freeway and to be driving 55-70 mph and to lose power for no reason is quite frightening. I love my vehicle, but this is very dangerous. It could easily occur when my daughter, a less experienced driver, is driving the vehicle. Please advise what is the cause of this and how can it be rectified? note that the first time this occurred, I had a lot less miles on my vehicle.

I was driving up to a busy intersection where there was a red light. I was just starting to brake when my steering got stiff and my car wasn't following the curve of the street. I looked at the dash and all my lights were on. My car had turned off. I didn't know if I was too low on gas but the gas light wasn't on. I put the car in neutral and turned the ignition, which started right back up. I pulled into the gas station and filled up the tank. I didn't have another issue until today, 9-9-15, when I was driving down a slight hill going about 40 getting ready to get into the turn lane when again the steering got stiff and I looked down and realized all my lights on the dash were on. I had half a tank of gas at the time. . . Both times I was able to put it in neutral to restart it without a problem. Both times have been on busy streets with my children in the car. . . . This is an issue!! I called the dealership where I bought it last year and since they were close to closing ended up not helping me. I will call them again tomorrow to find out what the heck is going on. . . .

While traverling ~ 45 mph and slowing approaching a curve and stop sign, engine shutdown completely losing power assist for steering and brakes plus engine power. Steered car without power assist and applied un-powered assisted brakes to stop short of stop sign. Car restarted without difficulty. This was a second occurance.