Brake failure / Unintended Acceleration / Unknown cause Driving at approx 25mph on urban street (road in good condition no potholes, ramps, etc) I began to slowly brake as I approached a red traffic light. Instead of braking, the car began to accelerate quickly. I pressed the brake pedal again - no response. Pressed down hard for a third time which executed an emergency stop. This all happened within 1 or 2 secs. There were no injuries or involvement of other cars on this occasion. However, had I been any closer to the car in front, I believe I would have rear-ended it. Had this occurred a few moments later, at the busy junction 400m ahead, it could have been fatal. I am absolutely sure it was not driver error. I was not distracted, drive regularly, and have been a confident and safe driver for over 30yrs. I have never experienced this in a car before, and in fact wasn't aware that it could happen until I researched it on this site. No warning lights or indicators came on. The car ran normally for the remaining 2 miles back home. I didn't think anything of it before, but prior to this incident (in our 5 yrs ownership) there were approx. 5 instances when the engine would "roar" as if it wanted to accelerate but didn't when I was breaking or slowing down on a highway. Also, there were perhaps 3 instances when the car felt as though it was "running away" i.e. a slight acceleration - for no obvious reason. As neither of these represented safety issues, I assumed the car was just a bit old and these issues would be addressed as part of any service. Now I wonder if they are related to the sudden acceleration. The car is currently having a "health checks" run, but nothing has been found. I am reluctant to drive this vehicle if neither my dealer or Toyota can discern the problem. Overall we have been happy with this car and its performance, but this is an unacceptable "anomaly" as far as safety is concerned. Vehicle available for inspection.

- Mclean, VA, USA

City street...pressed on gas after the light changed and it did not go forward and then waivered for awhile. I was very close to home. I do not know how it will work tomorrow. No warning lights were on. It has acted funny before like this on highway trips and then it wouldn't do it. Toyota dealers do not even know about them and it is annoying. It feels like a transmission slipping but has less than 70,000 miles. I thought maybe heat is doing it but now that it is out of warranty ie over 5 years old, I do not know what to do. I am unsure what causes this since no lights warn anything is wrong.

- Mesa, AZ, USA