From the beginning, my 2007 Prius (purchased 5/19/07) has consistently lost braking power briefly if I hit a small bump in the road as I am braking, at low speed, for a stop sign or traffic light. I understand this to be a problem in the transition from regenerative to hydraulic braking. My Toyota dealer, in May 2008, could find nothing wrong.

- Rochester, NY, USA

I am writing to report transient failure of the anti-lock braking system in our 2007 Toyota Prius. Since May 2008 we have noticed episodic accelerations during light braking (at intersections for instance) when the car encounters pot holes, grates, railroad tracks or slippery pavement. We seem to lose control of the vehicle momentarily. Only with heavy brake pedal depression does the vehicle come to a complete stop. Until January 2010 we thought this was a unique feature to our vehicle and we were hypersensitive to its idiosyncrasies. Unfortunately, in January 2009 this defect lead to a low speed motor vehicle collision wherein my wife was unable to stop the vehicle when another driver abruptly pulled in front of her. No one was hurt, thankfully, but both vehicles were damaged. All other nearby drivers were able to stop in time and no other collisions occurred. On December 4, 2009 this same vehicle was involved in another low speed motor vehicle collision when a driver ahead suddenly stopped to avoid a pedestrian. The Prius was unable to stop in time (even under heavy brake pedal pressure) and collided with rear bumper of the car ahead. More than $5,000 in damage occurred to the Prius alone; though no one was hurt. In both instances nearby and subsequent vehicles experienced no problems stopping. There were no signs of ice or slippery pavement either time. Furthermore, neither my wife nor I have ever been involved in accidents in the past or with other cars. We didn't recognize that this could be a manufacturer's defect until complaints to the NHTSA became public and widely discussed in December 09 & January '10. Please note, however; our affected vehicle is a 2007 model year and we have experienced symptoms including loss of control and inappropriate acceleration just as described by others in the online community for 2010.

- Evanston, IL, USA

I was driving my 2007 Toyota Prius in heavy rush hour traffic and cold, wet snowy conditions this past Friday night. My brakes failed to engage twice. The first time I was going 5-10 mph and stepped on the brake to maintain a safe following distance with the car in front of me, which had stopped. It was as if the car was in neutral and a yellow light started flashing on the dashboard (I think this was the ABS system light, but I don't know) and I fortunately coasted to a stop before hitting the car in front of me. There was no skidding or sliding, just a non-response from the brakes. The second time occurred about 10 minutes later and I was again traveling at slow speed and attempted to brake to stay a safe distance from the car ahead. This time I repeatedly pressed hard on the brake and initially there was no engagement and then after approx 5 sec the brakes did engage and I again was able to avoid a fender bender. I drove the car home (white-knuckled) and it has been parked in my driveway over the weekend - we experienced a major snowstorm and I have not been able to drive anywhere. Tomorrow I am going to see if I can get the car towed to a dealership because I don't want to drive it.

- Richmond, VA, USA

I was driving at low speed in cold weather, under 20 mph. I lightly accelerated to get through an intersection, then applied the brakes to stop because of a car stopped in the lane ahead. There was absolutely no response from the brakes so I ran into car in front. There was heavy damage to my car (estimated at $4,000 to $5,000), very little to car in front (less than $500). This is the only time this happened. The brakes worked fine for 2 years, and have worked fine since although I have only driven the car to the dealership for checking the brakes and to get the bodywork repaired. The dealership checked brakes, stated that there is absolutely nothing wrong (mechanically) with the brakes. Toyota had a regional representative investigate, and Toyota legal officially blames it on me not applying brakes in time. I have been trained to drive on the test tracks at GM's milford proving grounds, and have worked on engine and transmission software for 14 years, and have done a lot of testing on the track and road. I know how to apply brakes, and I know they did not work. Since the brakes are not just the mechanical apparatus, I suspect a computer problem.

- West Bloomfield, MI, USA

The contact owns a 2007 Toyota Prius. The contact stated that the vehicle experiences reduced braking ability in rainy weather conditions. On one occasion, the brake warning indicator illuminated on the instrument panel. She took the vehicle to the dealer, but they could not duplicate the failure and provide a remedy. The failure mileage was 12,000 and current mileage was 19,000.

- Nashville, TN, USA

The contact owns a 2007 Toyota Prius. While driving 3 mph, the ABS indicator illuminated when the brake pedal was depressed. The vehicle accelerated and proceeded ten feet. The vehicle crashed into a curb and punctured the tire. There were no injuries. The vehicle was towed to the dealer and they stated that the brake system was not the cause of the failure. The tire was replaced. The manufacturer stated that there were no current recalls on the brake system; however, they would have a factory service representative inspect the vehicle. The vehicle was inspected and it was determined that there were no current failures with the brake system. The current and failure mileages were 25,000.

- Armonk, NY, USA

The contact owns a 2007 Toyota Prius. While driving approximately 25 mph on normal road conditions, the vehicle failed to slow down when the contact depressed the brake pedal. She crashed into some bushes on the side of the road and proceeded to a complete stop. The failure occurred without warning. The vehicle was able to be driven to an authorized dealer, but they were unable to duplicate the failure. The failure occurred another time and caused a rear end crash. There were no injuries. The vehicle has not been repaired. The contact was concerned of the safety risk involved. The VIN was unknown. The failure mileage was 20,000 and current mileage was 24,000. Updated 11/25/08. The consumer stated the second time the incident happened, she stepped on the brake, the pedal went down to the floor with no resistance and the consumer crashed into another vehicle. Updated 11/25/08.

- Venice, CA, USA

2007 Toyota Prius with brake problems. Consumer states that the brakes were pressed and the vehicle continued to move backward slowly. He also states that the vehicle didn't stop when brakes were depressed and consequently hit a stopped car.

- Sterling, VA, USA

This incident involves my 2007 Toyota Prius hybrid that I have owned for almost a year. As I was driving approximately 40 mph and put my foot on the brake as I approached a red light, the red brake warning came on the dash as did the ABS warning light. My foot went all the way to the floor and I had no brakes. Luckily I had a right turning lane that I could veer into and not hit the stopped vehicles in front of me. As I continued to push the brake to the floor and maneuver the vehicle out of traffic, it seemed to catch a little and I was able to slow the vehicle eventually to a stop. I put the vehicle in park as it was still running, and pulled out the owner's manual. The manual specifically stated that if these two warning lights came on at the same time, you were to "stop immediately and contact your Toyota dealership". this is exactly what I did. I had the vehicle towed into their facility that evening. The next day I was interrogated by the mechanic after a diagnostic report was done on my car. He wanted to know when I let the car run out of gas. I have never let my car run out of gas, and in fact that just filled the take the day before this incident occurred. The mechanic couldn't tell me what was wrong and contacted Toyota's corporate office. Two days later, I was advised that the reason the brakes didn't work was because I "let the car run out of gas "and this caused the engine to shut off. I argued that the car had never run out of gas and the engine didn't shut off, the brakes went out. The service manager pulled out the diagnostic test showing that "at some point" the car had run out of gas----this test doesn't give a date of when this may have happened. I advised the service manager that the car had 223 miles on it when I purchased it-- this test result could have happened when the car was still at the dealership, not in my possession. The service manager advised me that his "hands were tied" and that Toyota had made their decision.

- Anthem, AZ, USA

When attempting an emergency stop, the brakes failed to operate as expected. There was no feeling of any braking, and there was no surge to indicate that the ABS was operating. The experience was similar to those reported on the web page www.hybridcars.com/forums/brake-failure-2007-T1013.html?S=500A78277ea2cb675fac1F9567000bee& I have taken it to a Prius dealer, avondale Toyota, but in the absence of any computer codes and the fact that subsequent tests of the ABS system did not indicate a problem they were unable to offer any kind of explanation or repair. I had approximately three to four car lengths from me to the next car at about 30 mph, enough space that I believe I should have been able to brake without collision. When I went from accelerating to rapid braking there was no real sensation of the car slowing down more than slight braking. The other car had minimal damage, but the driver of the other car did hit her head on her steering wheel. I had close to $3,000 in damage to my front end (hood bumper and left fender). The consumer was informed that there was nothing wrong with the brakes design. The brakes are electronically assisted and that the computer will first attempt to use the electric motor for initial braking, then engage the hydraulic system and finally the ABS based on feedback from various sensors. The mechanic did agree, that is possible that while the computer is evaluating the braking efficiency, a delay between the motor only braking and fully engaging the hydraulics and ABS are possible and part of the design. Updated 08/02/07.

- Glendale, AZ, USA