2010 Toyota Prius Owners Manual - Page 533
2010 Toyota Prius Manual
Page 533 highlights
5-2. Steps to take in an emergency Warning message Details (Flashing) Indicates a malfunction in the radar cruise control system. A buzzer also sounds. Stop the vehicle in a safe place. Turn the "POWER" switch to OFF and then to ON mode again to reset the cruise control system. (If equipped) 5 When trouble arises 511