Second occurrence of this problem in three weeks. Driving downhill on a residential street at 25 mph, slowing to a stop without applying the accelerator. Suddenly lost engine power. Applied accelerator, no response. Continued to lose speed as I rolled silently downhill toward the intersection. Applied brakes and stopped. Restarted the engine and it started up fine. The previous incident also occurred on a downhill grade, on an exit ramp from an parking garage. Fortunately both incidents happened at low speed and not in heavy traffic. I previously reported the first incident. Toyota dealer checked vehicle after each incident and could not replicate the incident or find a computer code that would explain it. Since this was the second occurrence and was familiar to me, and since I was not in traffic, I let it happen while observing my own actions, trying to check for driver error. My foot was not on the brake.the car was in drive. While the car was slowing, I tried pressing the accelerator deeply and then pumping the accelerator to see what would happen.. there was no response, and no sound. The same was true three weeks ago-no response to pushing the accelerator, even deeply, and no sound. Three weeks ago, the first time it happened, I also tried cycling through the "modes" (ev, Prius, eco, power) with no effect. Each time, I hit the power button to power off, and then I hit it again to restart. Powering off and then restarting, both times, seemed like "rebooting" a computer. Fortunately traffic conditions both times gave me ample time to reboot. Will this happen again?

- Bethesda, MD, USA

2010 Prius accelerates while braking and surges in acceleration from a stop while accelerating slowly. Many but not all occasions were while going over bumps and/or wet road. This has happened several times since owning the car. Toyota cannot duplicate the problem in the testing and denies that it is real. It has been brought into Toyota for repairs but the problem persists. The car is now parked and we will not drive it as it is not safe. We filed a lemon law claim (ca) and Toyota has denied the claim with a form type letter.

- Penngrove, CA, USA

My 2010 Toyota Prius will sometimes jump forward or backwards when you put it in drive or reverse. This only happens for a split second. Concerns me if it is safe. It has done it 5 or 6 times.

- Clifton, CO, USA