Owners/service Manual problems of the 2018 Toyota Corolla

The car was in stationary mode on a city street and waiting for the red light to turn green. After a few minutes, the turned green and I accelerated a little as the car begin to move but out of nowhere the car turned off and all systems stopped, including the computer board, but before all went blank there was a message about system error with a triangle symbol, and I had to manually activate the parking lever as well as press the brakes. Thankfully everyone in their lanes noticed my odyssey and made space for the other upcoming cars as I activated the emergency flashing lights. However, I turned the car fully off by turning the key and waited some minutes as I was adjusting to the situation. I then turned the car on again and worked. A few days after the incident, I took the car to the dealership and the staff member who assisted me said that the system's record showed that there as an error history but did not say which component part or where the malfunction was located that caused the car's safety risk in regards to the computer system and engine to stop without any notice. This response to what happened was not satisfactory to me because nothing was done and no paperwork or record was given to me about the system check or report. This incident and unknown response to the malfunction cause have made me worry about this happening again in the future under other unsafe circumstances and that it could cause me to have an accident.