My wife and I just experience a similar issue with our brand new Leaf...
While driving on the freeway, the engine died and immediately flashed multiple unrelated yellow warning symbols (traction system warning, brake system warning, electrical system warning) when I had just driven the car about 25 miles and still had 73 mile range left. It first went into turtle mode and with my momentum I was able to get it to the right side of the freeway. I was lucky I was not driving in the fast lane.
Then after a few minutes the car would not go into drive or reverse, only Park or Neutral. Powering on and off did not help.
I had to tow the car to the dealer. After the Nissan Dealer service dept did troubleshooting and called Nissan, they determined the Accelerator Pedal Pressure Sensor had failed. Two days later the sensor was installed and I was able to drive it back home. I had a loaner and insisted they also pay for the gas due to the inconvenience any my lost time from work. They were friendly and helpful.
Today, my wife took the car to drive to work, and less than a mile from home the car died in the middle of the main highway through town. Turtle mode only lasted a few seconds so she was stuck with a car that could not move to the side of the road. I talked with her on the phone for a few minutes and she powered down and up again, and this time the car started as if nothing was wrong. I told her to drive it back home so that we could deal with it tonight after work. She was able to make it home and I scheduled a tow back to the dealer to get this fixed. Very unhappy that this issue was not resolved the first time. Will need to see if they can figure this out. I hope it does not become a 7 week troubleshooting party like the prior user wrote above....
We really like the Nissan Leaf. This is our first Nissan car after driving nothing but Hondas and Toyotas. I hope they can address this quickly.