Last night I turned on energy saving mode. This morning when I went to drive the car it displayed a message that stated something like; preparing, press brake to start after message clears. But the message did not clear. The car would not start and the user interface was locked out. I called the SC and the first question he asked me was if I had turned energy saving mode on. I told him that I had the previous evening. He asked me to reboot, holding both scroll wheels down until the tesla logo appeared in the center stack. He said that when the car is in energy saving mode that the software modules go into power saving mode and that if they don't power back up in the correct order then what I experienced will occur. So I'm not using that any more! apologies if this issue has been previously discussed.