Three problems related to engine shut off without warning have been reported for the 2008 Toyota Prius. The most recently reported issues are listed below.
My 2008 Toyota Prius shut off while I was driving on the road I could've involved in big accident if I was on a highway the way it shutdown without any warning sign. It just suddenly stopped.
I was driving 50mph when the car lost power. The car suddenly had no power brakes, no ability to easily steer, no engine power and many warning lights came on including an warning that the main hybrid battery was not charging. The car would not respond to acceleration. The car came to a stop. I held the start button the car shut off. The car restarted with no problems. All the warning lights were off. I put the car in drive and started to accelerate. All the warning lights come on just as before and the car suffers the same issues again. I went through the same process of turning the car off and turning it back on. The car started up again with no problems again, all the lights were off. It failed on more time on the trip home. I was able to restart the car and put my emergency lights on. I never drove over 25mph on the trip back to the house. My family took the car to wilson Toyota in bellingham wa. They examined the car and said the 12v battery had failed. They told my family that the main 12v battery runs all the electrical to get the car started and running. We told the dealer the car still had electrical power. They still replaced the 12v battery. The following day my family went to look at the car and a service person at the dealer, who said he was new to this location, said he had noticed that the 12v battery had seemed to be replaced recently. They said they would keep the car to keep looking over its systems. On 4/16/2015 my family called Toyota to discuss our safety concerns with regard to how the car failed. We explained we also have a 2007 Prius that had the main hybrid battery fail and that all the warning lights that came on were similar in both cars. The dealer has said there are no codes that said the main hybrid battery is failing. I am worried that I or my family could be seriously injured if the car failed in this manner again while on a busy highway or intersection.
Driving on sb hwy 35 at 74mph, master warning light came on and vehicle shut down, no electrical or engine control. Pulled safely to shoulder of road. Car would not restart. Got out of car, locked car, unlocked car (Toyota technician instructions), then car restarted. Got car off the road, contacted state farm for tow to autonation Toyota south austin. Toyota technician removed a third party telematic device (in-drive) from obd port. Vehicle diagnostic scan showed two communication errors u0100 and u0111. Third party telematic device was not reinstalled. Vehicle was test driven, held overnight, test driven again and the errors or shutdown did not repeat. Toyota service manager said they have seen third party devices connected to odb port cause errors and have to be removed or replaced. We have three hybrid vehicles in our household each with a third party telematic device from in-drive. All three have been removed and returned to in-drive with supplied packaging and return instructions.