Adaptive Cruise Control problems of the 2020 Hyundai Tucson

It happened on two different occasions but only when driving at high speed using the cruise control. Here is what happened. Driving on the cruise control I “set” it to 70 mph. Driving on the two lane highway with both lanes blocked by other vehicles, I pressed the “brake” pedal. The car slowed down and I continued driving at a lower speed. When traffic in front of me cleared, I pressed the “resume” button on cruise control. With no obstacles in front of me, my car was supposed to accelerate to the previously set speed of 70 mph. Instead, it was slowing down. When pressing the gas pedal the car was not accelerating. It felt like the car “lost power. ” it felt like the automatic transmission shifted to a neutral or may be the lowest gear. Pushing the gas pedal did not do anything and on both occasions I managed to steer the car to a road shoulder. It was a scary situation with heavy fast moving traffic on a narrow mountain highway. I stopped the car, then tried to go again. It would go very slow on, what felt like, the lowest gear without acceleration. I then stopped the car again and turned off the engine. Turning the ignition off resets the electronics and I was able to get back on the road. The car continued to drive normally on cruise control until the same happened again the next day. As I said, it happened on two different occasions. From there on I avoided pushing the “resume” button on cruise control and I am afraid of using it from now on to avoid potential accidents. I consider this to be a life threatening malfunction and I reported it to Hyundai’s customer care. They opened the case number and suggested going to the nearest dealer. I took the car to the nearest dealer. They kept it for several days, drove 40 miles and, as I expected, were not able to replicate the problem. In my opinion, this problem needs to be analyzed by the engineers not a dealership's technician. Is speed a factor? is temperature a factor? what is the factor?.