My car was parked on the street, I got into it, turned it on, shifted to driving and started proceeding forward. I then noticed 3 lights (the ABS light, brake light, and traction control light) suddenly appeared on the dashboard. Nothing out of the ordinary occurred prior to the light coming on, it just suddenly appeared. The error code in the computer system read C1391. The details read there was "abnormal leak in accumulator". the car no longer drives safely. If the brakes are pressed suddenly the car skids instead of slowing down. In order for the car to come to a complete stop a lot more pressure has to be applied to the brake compared to before ABS problem. The stopping distance has increased by approximately twice its length. The car is no longer capable of sharp turns, the back end of the car skids dangerously left or right while turning, depending on the direction the driver is turning. The braking, handling and control of the car decreases so much when the roads are wet that at times the car skids even when going at a cautious speed in rain. For my safety and for others I drive in "B" instead of "D" when it rains.

- Houston, TX, USA

Brake light, antilock light, vehicle stability light, and yellow trains came on. Having problem with braking. Does not not seem to brake as good. It is very dangerous when driving.

- Mobile, AL, USA

The following dashboard lights came on on our vehicle at the same time:traction mode, emergency brake, ABS, and brake system warning light. Since the lights have came on, I have noticed that I have to press down further down on the brake to stop the vehicle. My stopping distance is further now as well.

- North Fort Myers, FL, USA

When breaking and still moving, the car will accelerate momentarily resulting in going faster for a second or two. This happened randomly over the years and may in some instances be related to hitting an irregularity in the road, but I cannot be sure. It has not caused an accident, but is strong enough that it could. I'm a pretty safe driver so tend not to ride on the tail of the car in front of me. I have not kept track of when it happens.

- Plymouth, MN, USA

The car stop working all the dash lights stop working, the brakes start getting harder and the don't stop at all and beeping without stop that noise and the hibryd system stop working after I living for some recalls repairs and the want me to fix the car to pay and I know is not my fault everything is because is this car is all electronic system.never on my live I have this problem with my other cars.only with this one and now they one me to pay for something the company makes wrong.this is not fair at all.before I was recomended this car but right now people ask me and I have to talk negative situation about it.

- Enfield, CT, USA

When I brake on an uneven surface (potholes, bumps, etc) the car will sometimes jump forwards. I am unsure whether it is referred to as brakes slipping but it is exactly the same thing that I've read happening to many people. It was an issue in the 2010, which led to a recall, yet there is no recall on the 2011. It doesn't make any sense, people have said that the actuator was the part that needed replacing, yet it is a $3-4K part and should not be left up to the consumer. This is a safety issue and is a known problem and needs to be addressed by Toyota. It has been happening ever since I've owned the car. I have been lucky so far that it hasn't accelerated me into another car or person.

- Agawam, MA, USA

While deploying brakes if you go over bumps they fail to brake properly. Feels like a speed up. This has happened numerous time while braking for traffic light or making turns.

- Rome, NY, USA

All of the brake lights on my dash lit up, brakes weren't working well, took it to the repair shop and was told it was my brake actuator.

- Pflugerville, TX, USA

I'm constantly hearing a barking/ purging noise coming from the brake accumulator pump whenever I do hard braking. Whenever I hit potholes or rough roads, the car would still rolls during braking as if the ABS is getting triggered. I was quoted by Toyota dealer of an estimate of $3000 to replace the brake accumulator pump and booster. I'm afraid that the brakes would fail while driving.

- Buena Park, CA, USA

I was on driving on the freeway when suddenly traction control light was on and brakes seemed to have locked. The conditions of the road were dry and I was driving the speed limit. This occured on a few different occasions. One day brake light, ABS and traction light all appeared. Took it into Toyota dealership and was informed it was brake booster.

- San Diego, CA, USA

The vehicle was in motion. Several warning lights on the dash came on at once, and the brakes required significant additional pressure to operate. We drove he vehicle home, and then to a nearby repair shop. We were informed that the brake booster had an internal leak, and required replacement. This is the same part that was addressed in a customer support program for the 2010 my Prius; however, the 0211 Prius is not covered. 110,000 miles.

- San Antonio, TX, USA

Toyota had a customer support program zjb for default brake booster/master cylinders on the 2010 Prius models. I have a 2011 Prius that has been diagnosed with the same problem and there is no customer support offered. This warranty enhancement on the 2010 models is good thru 11/30/19 regardless of mileage. Even though my vehicle has the exact problem there is no recognition for support due to the year of this vehicle. I was not aware I even had a problem until I took it to the dealer for a software recall update. We were experiencing heavy rain and my indicator lights came on which is why they checked this and confirmed the issue although my brakes are working fine. I am not understanding why Toyota is not honoring the fix for the default or why after discovering this issue in 2010 the 2011 would not be considered. I would appreciate some help in this matter.

- Nashville, TN, USA

The following is a summary of how I became aware of the power booster and master cylinder problem with my 2011 Toyota Prius. 'upon discovery of multiple lights displayed on dashboard such as brake, ABS system & traction lights, during driving the braking performance has changed drastically & the car no longer performs braking function adequately. Unable to rely on safe braking due to brake resistance felt with stiffening in which pedal depresses deeply & more time is required to come to a full stop. When braking the hybrid battery does not charge & runs dangerously low resulting in damage to the hybrid battery which can lead to substantial cost to replace the battery. 'car brought to Firestone for diagnostics. Upon further inspection by their technician it was determined that the power brake booster/master cylinder was damaged & malfunctioning and was in need of replacement. Informed repair would be in excess of $1,500. See enclosed supportive documentation from Firestone diagnostics.

- Pembroke Pines, FL, USA

ABS actuator malfunction

- San Antonio, TX, USA

Brake accumulator failure. Specifically repair T-sb-0079-18 ABS, traction, brake lights on. Brakes not as responsive/spongey. No regenerative energy from braking

- League City, TX, USA

The contact owns a 2011 Toyota Prius. While driving 65 mph, the brake pedal was applied and was stiff. The contact had to tap the brake pedal to slow down the vehicle. In addition, the brake and ABS indicators were illuminated. The vehicle was taken to charles maund Toyota (8400 research blvd, austin, tx 78758 (866) 797-4354) where it was diagnosed that the brake actuator needed to be replaced. The vehicle was repaired. The manufacturer was contacted and provided case number: 1901140996. No further assistance was provided. The failure mileage was 119,384.

- Austin, TX, USA

The attraction brake and ABS lights come on, the brake become spongey and fail to stop the vehicle, I almost had an accident while this happens while I was driving the vehicle

- Lawrenceville, GA, USA

ABS lights on, tracks warning lights on and vsc lights on.its a serious problem. Toyota should fix it. Toyota should own its problem

- Wellington, FL, USA

Brake booster and actuator failed and error code C1391. Vehicle is unsafe to drive and Toyota knows this problem because of the number of cases involved with this issue. The year prior saw a massive recall of 87,000 vehicles with the same issue. The same issue has carried over and Toyota refuses to be held responsible for this issue.

- Orlando, FL, USA

Brake actuator has gone out giving a code of C1391. I have had the car less than a year and the brakes are now grabby and not functioning properly. This is a known problem with the gen 2 Prius (my previous car) and was covered under an extended warranty. Apparently the gen 3 Prius has the same issue and Toyota has extended the warranty of the 2010 Prius to the manufacturing date of 11/2010. My Prius was manufactured in 12/2010 and I was just notified it would be $4000 to fix the issue that is a known manufacturing defect. Apparently Toyota didn't fix the problem the first time and it's a direct safety issue when the brakes don't work as intended.

- High Springs, FL, USA