NHTSA Complaint #11545878 — 2015 CHEVROLET SONIC

First sign of problem - Sept. 2021. Driving on highway at about 35 mph. Simultaneously, engine quit running, door locks unlocked and all dash lights came. In a matter of less than a second the doors relocked, forward momentum of vehicle caused transmission to kick start the engine and jolt forward rather violently. Then the dash lights went off and the vehicle resumed normal operation. This continued to happen with increasing frequency. I took the vehicle to the local Chevy dealer to set up an appointment for service. When I explained the problem to the representative, he told me that the battery was the likely cause. I went to an auto parts store and had the battery checked. It did, indeed, have a bad cell. I replaced the battery and the car operated fine for several months but the problem began to recur, infrequently at first but continued to worsen. I discovered later that the same problem also happened when when the car was sitting idling. The difference was that without the forward momentum of the car, the engine did not restart and required being shifted into neutral and started with the key. Also, when driving at a speed of less than about 30 mph, the forward motion was not enough to kick start the engine and shifting into neutral and using the key to restart was necessary while coasting in traffic. Final symptom, the above has happened only now the dash lights go out and the vehicle does not respond at all. After several minutes and several attempts the lights come back on and the vehicle runs. The car had 55,563 miles on it when I bought it and in just over 3 years, I have put 6,237 miles on it and it now sits because I am afraid to drive it. I have had the vehicle back at the dealer twice since having the new battery installed. They simply tell me that they cannot recreate to get a code and therefore cannot help.