In the middle lane of a multiple lane highway, it suddenly gave a very confusing warning on the dashboard. It lost power and slowed down quickly to below 40 mph. It didn't help to press down the gas pedal. I was forced to switch from the middle lane to the passing lane in order to reach the shoulder. The car was side swept by another car in the passing lane because it was at low speed. Once it reached on the shoulder it stopped completely. If it gave a clear warning, for example, "pull out immediately!", and flashed the emergency light automatically, it might save a few seconds, and gave a warning to cars behind. It's a PHEV, and I believe that it used up the battery for driving but failed to automatically start the gas engine.

- Rockville, MD, USA

While my wife and I were driving on the interstate, all dashboard warning lights came on at once, and the car began rumbling at regular intervals as it tried and failed to switch from electric vehicle (EV) mode to hybrid EV (HEV) mode, and the engine wouldn't start. At the same time, the power steering stopped working, the car struggled to go more than 40 MPH, and it started accelerating on its own and would not stop until I hit the brake. Each time the engine tried and failed to start, the car started accelerating again. I pulled off at a gas station, turned the car off, and called for a tow. I tried to turn it on again but got a "Check Hybrid System" message and could not start the car, so I had it towed to a dealer. They diagnosed it as a dead 12-volt battery; however, they had none in stock and would be unable to get one for 2 weeks, so they charged the 12v and told us we should be able to get home. It happened again a few hundred miles later, and the situation repeated itself. This 2nd dealer also diagnosed that the issue was the 12v but couldn't get one in for at least a week. We rented a car, drove home, and when the dealer replaced the battery, they shipped it up to us. A week later, the car's big battery (not the 12v) was failing to charge, so we brought it to another dealer. They claimed they had no trouble charging it and returned the car. Shortly after that, it died again, in the same fashion described above. We took it back to the dealer, and they had it for over a month, claiming they could not replicate the problem. They returned the car, having diagnosed no problem, so I drove around the dealer and replicated issue myself. It took 15 minutes for the check engine light to come on. I brought it back to the dealer. When they got in the car, the power steering was dead, and the car could barely move. They've now acknowledged that the problem exists and are trying to diagnose it for a 4th time (5th if you count when I was unable to get it to charge).

- Pittsburgh, PA, USA