On May 26, the car was running in electric mode and switched to gas because the power batteries were depleted. Shortly after switching to gas mode, lights came on the dash board saying Engine Not Available Get Service Immediately. I was on a highway at the time and fortunately had just enough left to get off and the car would not move any further. Turning the car on and off did not resolve the problem. It had to be towed to a Chevy dealer. Even after an hour, the messages would come on when trying to start the car. The next day, the dealer called and said they could find no problems with the car and it works fine. This happened once before, but that time there was enough charge in the battery to get home and then later it would start without the message.