2019 Kia Niro

There is a pause upon acceleration from a stop (unresponsive). Then the vehicle will lunge forward and make a loud noise. For both driver and passengers, it can be quite startling and feels as though the car has been hit from behind. This started happening in the fall of 2021, when the car was about two years old with about 18,000 miles. It has happened about a dozen times in the six months since first noticed. It seems that this may be a software issue related to the hybrid system - a lag in triggering which motor to use for acceleration.

Multiple problems with transmission and electrical. Electrical: 1) While traveling 80mph in the far left lane of the highway, I had to make a hard break when someone changed lanes and moved into my path. When I did that, the car turned off completely. (The key fob was still secured in my cup holder.) I could no longer accelerate and it was slowing down quickly. There was no way for me to turn the car back on using the start button. I could do nothing but try to cross 6 lanes of oncoming traffic to get to the roadside in order to stop, which was extremely dangerous on a busy highway. I was very luck I didn't get slammed from behind and end up in a horrible accident. Once I got to the roadside, I stopped the car and was able to re-start it. Kia mechanics said a diagnostic turned up nothing, and they could not "duplicate" the problem. Of course, they can't guarantee it won't happen again. 2) Another time, I turned off the car after parking, grabbed my key and exited the vehicle. It started loudly beeping at me. It's the sound it make when the key fob is taken from the car while it's on, or you try to lock the car and leave when it's still on. I had to turn the car back on and then back off in order to resolve the issue. Transmission: Transmission was replaced at 19,000 miles because the gears were grinding when I was downshifting and it wasn't shifting from 3rd to 4th well. I'd put my foot on the gas and it just wouldn't go, and then it would finally kick in. I was also having issues with it when parking or coming to a stop. It would get to a point when the car was slowing down and should now coast slowly, and instead, it would come to a sudden stop, then it would jerk forward. When on any kind of an incline, it would stop, roll backward, then catch and roll forward. It seems to suddenly shift into neutral when I'm not in neutral and it should be moving forward. New transmission addressed grinding, but other issues remain. I also multiple issues accelerating now. On May 12, after driving the car to a nearby sto