One problem related to engine shut off without warning has been reported for the 2006 Toyota Prius. The most recently reported issues are listed below.
2006 Toyota Prius gasoline engine shut off. The following light illuminated on the dash: master warning light, hybrid system warning light, brake system warning light, vehicle stability control system warning light and malfunction indicator warning light. The vehicle continued to operate at a low speed on the electric engine and the consumer was able pulled onto the side of the road. The consumer shut the vehicle off then after a few minutes started it back up. The vehicle operated normally but all the light were still illuminated. The vehicle was parked until the next day. When the vehicle was started the lights were no longer on and the vehicle operated normally. The vehicle was taken to the dealer who could not find anything wrong with the vehicle.