general problems of the 2015 Toyota Prius - part 2

Before, I was driving and occasionally the traction control light would flash when I put my foot down on the brakes but would go away when released. I didn't think much of it but then a few days later, I went to brake to stop the car and then the abs, traction control and brake system lights lit up on the dash and wouldn't go away. I pulled over safely and turned the car off and on again but it wouldn't go away. The brakes were also noticeably more firm compared to before as it was quite squishy but now it was solid and all regen braking went away and it appeared I had no more abs which could lead to a collision. I immediately took it into the dealer to have it diagnosed. I did some reading and if I kept driving with this problem, eventually the brakes would fail and collapse completely and leave me unable to stop the vehicle. At the service center, they were able to read the code dtc c1246 and clearing the codes did not work. The part that was replaced was the brake booster and the brake master cylinder and the brake pedal stroke sensor. It appears that a warranty program exists for this issue but it is not a recall. I am also not sure if the part that was replaced is a revised part that will no longer have this issue or there is no change in the part design. I believe this is a massive safety issue and should be a recall and not a warranty replacement program as every Prius should be recalled for this defect. I was very close to being out of warranty and if I had taken any longer to bring it into the dealer I would have been out of the extended csp warranty. Even the dealer initially thought I would be out of warranty but I had to argue that I was in warranty and should be eligible for a warranty replacement and that I should not need to pay for a diagnostic fee despite it not being a recall.

I have a 2015 Toyota Prius with 48,600 miles. My breaks started failing suddenly while driving which almost got me into a car accident. I took it to my mechanic immediately and the dtc was code c1281. I was advised to take the car to a Toyota dealer. I got an appointment and a manager was waiting for me wanting to charge me $250 for a new diagnostic test and $2,500 - $3,000 for repair if the diagnosis was correct. I called customer service and washed their hands from any responsibility. I called the Toyota's customer advocate service located in plano, TX and was on the phone for more than an hour. They apologize, were very courteous, but I was told that I was not covered because I had call too late and that the repair offered by Toyota had expired. They acknowledged that Toyota never issued a recall for this manufacturer defect. I informed them that the discovery of the problem had occurred on [xxx], 10 years and 2 month after I bought the car from them and that the car was almost new with very little mileage. I let them know that felt this was a deceptive trade practice with breach of warranty and breach of implied warranty of merchantability, along with it being a fraudulent concealment with failure to warn their customers of potential danger and harm. I plea with the Toyota's advocate that since the statute of limitation and equitable tolling had not elapsed from the day of discovery that they should honor my request for it being just. I was told that Toyota's decision on the Prius brake defect was not covered and that I was free to take my car to a Toyota dealer or an independent mechanic, whatever was more convenient and/or affordable and that the cost was on me. I asked if I were to get a new Toyota car and trade in my old car if they would appraise it as if the defective brake part had not malfunctioned. The answer was that the value of my car if traded in, would be significantly less due this issue. He gave me a ref # [xxx] and hanged up. Information redacted pursuant to the freedom of information act.

Our 2015 Prius suffers from the brake booster/master cylinder defect as outlined in TSB t-sb-0024-19. Which is a well known an pervasive issue for this vehicle. We were unable to medically drive when the vehicle was still under the time frame and mileage which would have allowed it to be covered by Toyota. Despite requesting an extension due to extenuating circumstances (medically unable to drive, thus detect the issue during the covered period) they disclaim any and all remedy. When I was able to drive the vehicle after being cleared from surgical recovery restrictions, the issue was immediately found and reported to Toyota whom promptly denied the claim through their local dealership and subsequently through their offices after sending a letter requesting an exception or good will extension. This issue is a major safety issue and unfortunately also a cost prohibitive repair to take on. The defect in question is acknowledged by Toyota through multiple TSB's and warranty extensions and their own zjb customer support program. We are under the actual mileage cutoff but outside the time frame by a few months (medical period where the vehicle was not driven).

Code c1391 leakage in accumulator abnormal. This required replacement of the master cylinder, brake booster pump assembly. This fault resulted in mushy brake pedal and loss of abs system. The components were replaced at a Toyota dealership. Total cost was $3207. 82. Apparently this was a known issue with Toyota for Prius models 2010 through 2015.

The brake booster pump and abs actuator is beginning to fail recently. I took it to the Toyota dealership to use customer support program zjb to replace the parts, but they said my vehicle was not covered. They then quoted me $3000 to fix the issue. The brake booster pump and abs actuator contribute to safety while driving, so why is this not recalled? we need an official recall to happen and not a simple customer support program.

Brake booster failed. Abs lights on. Brake light on. Traction control light on. Was sitting at stop with foot gently on brake when lights turned on. Attempted to restart car to clear lights, lights would not turn off after normal restart x3. Brake no longer function correctly, and the factory installed abs are no longer functioning. Braking distance greatly increased, and no longer as safe to operate.

Failure of the: pump break booster actuator had it towed to Toyota and they said it’s a $3,500 repair.

2015 Toyota Prius abs warning light came on . Went to car mechanic . Brake actuator & pump code leaking. It happen on 7/27/25 under 100,000 miles. Currently anti sway and abs braking disable.

While driving my Prius on the highway, the abs and traction control warning light suddenly came on. The brakes started feeling different right away, and it didn’t feel safe to drive. I took it to a Toyota dealership, and they found that the brake booster and pump had failed. I looked online and saw that many other Prius owners had the same issue, so it doesn’t seem like an isolated case.

Hi, I am reporting a brake system failure on my 2015 Toyota Prius. In July 2025, the abs and brake warning lights suddenly appeared, and a Toyota service center confirmed it is the known Prius brake system defect. The repair estimate ranges from $4,502 to $27,814, but Toyota declined coverage because the vehicle is just past the 10-year warranty limit. This issue poses a safety risk due to reduced braking performance. 1) the brake system / abs actuator assembly malfunctioned. And yes, the component is still installed in the vehicle and available for inspection upon request. 2)the abs is no longer functioning properly, significantly increases the risk of losing control or extended stopping distance, especially in wet or emergency braking conditions. I rely on this car for daily transportation in a car-dependent area, so this issue directly affects my ability to drive safely and could endanger others on the road. 3)yes. The issue was diagnosed and confirmed by an authorized Toyota dealership center. 4)yes. The vehicle was inspected by an authorized Toyota dealership only. 5)yes. The abs light, brake warning light, and other dashboard indicators suddenly appeared in July 2025.

Brake light + abs + traction light came on and the brake became harder to control. I was driving in the rain and briefly lost control. Fortunately, no accident.

Omponent/system involved: service brakes, hydraulic ? make: Toyota model: Prius year: 2015 mileage: 155,470 VIN: [xxx] ? what happened: my 2015 Toyota Prius is experiencing brake failure symptoms related to a known defect addressed in Toyota’s warranty enhancement program zjb. The vehicle has triggered dtc codes c1256 and c1391, which indicate failure of the brake booster and master cylinder — a problem widely reported by Prius owners. The defect causes decreased brake effectiveness and increased stopping distance. My Prius is just 5,470 miles over Toyota’s 150,000-mile coverage cap, and despite confirming the exact codes, the dealership refused to repair unless Toyota pays first. Toyota corporate opened case #[xxx], but has not offered a resolution. This is a safety-critical issue that Toyota acknowledges in internal service bulletins, but they are denying assistance based on a technicality, despite my vehicle having the exact failure their program is designed to address. I am filing this complaint because I believe Toyota is avoiding responsibility for a dangerous manufacturing defect affecting braking performance and safety. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Failure of brake pump and brake cylinder assembly system, resulting in reduced braking ability and stiff brake pedal. Per Toyota's diagnostic: trouble code c1391 is present, abnormal leak in accumulator, replaced brake abs actuator assembly, along with brake master cylinder, and bleed the brake hydraulic system. No warning lamps or safety indicators prior to failure. Upon failure (while on freeway going 50+ mph) the abs, brake, and traction control warning lamps illuminated. The failure resulted in no accident or injury, however it did occur while on the freeway going freeway speeds, and resulted in difficulty in braking, which was dangerous. Took Prius into Toyota dealer for diagnostic and repair, was told that part was known to fail in this model of Prius, and had a manufacturer designated extended warranty for 10 years or 150,000 miles. However, despite Prius being under 150,000 miles, it passed ten years since purchase in March 2025, meaning I had to pay in full for the repair ($3,631. 96). The car gave no indication of needing the repair until the day of the failure, which was on June 18th 2025. If the vehicle had given some prior indication of brake pump system failure or fault I would have had it repaired prior to the warranty expiration, but it did not, leaving me to pay out of pocket for a failed part that Toyota is at fault for making prone to failure.

While driving my 2015 Toyota Prius, the brake pedal became extremely stiff and hard to press. I was on the way to the dog park with my dog in the back seat when I had to press down very hard just to slow the car at a traffic light. It felt like I was stepping on a rock. The brakes barely engaged, and I had to use far more force than normal to get the car to stop in time. When I hit the brakes, they finally caught hard and suddenly and my dog went flying off the back seat and landed on the floor. She’s fine physically, but now she’s terrified of getting in the car at all. It was scary for both of us and felt totally unsafe. If I had been going just a little faster or if someone was walking across that intersection, it could’ve ended badly. I later found out this issue is tied to a known defect with the brake booster and accumulator system, specifically related to code c1391. Toyota even acknowledged this problem in a customer support program (csp zjb/zkk), but they refuse to help because my car is slightly over the mileage limit. That doesn’t change the fact that this is a serious, dangerous failure that affects the driver’s ability to stop safely. Toyota should be forced to take responsibility for this failure before someone gets seriously hurt.

In June 2025, while driving on the highway, the vehicle suddenly displayed multiple brake warning lights and warning messages, including the red brake warning light, abs light, brake system warning light, and traction/slip indicator. At the same time, the brake pedal became stiff and braking effort increased suddenly, creating a near-crash situation because the vehicle did not slow normally. Before that incident, the vehicle had already been making abnormal brake-related noises, including a humming/pumping noise when the brake pedal was applied, and there were intermittent episodes where braking felt abnormal. In June 2025, the vehicle was taken to a Toyota dealership during Toyota’s brake booster support program period. The dealership documented customer complaints of “humming noise in cabin when holding foot on the brakes,” a request to “scan for codes for zjb enhancement,” and that the “vehicle hard to accelerate and brakes got stiff,” but stated that no qualifying abs codes were present at that time. In March 2026, the same condition returned and worsened. The vehicle again displayed the red brake warning light, abs light, brake system warning light, and traction/slip light, and braking performance was reduced. An obd scan of the abs control unit showed code c1391, which is associated with brake booster / abs actuator failure. The Toyota dealership has now diagnosed the vehicle with abs actuator and brake booster failure and quoted repair. This is a serious safety issue because braking became more difficult while driving, including on the highway, with sudden warning lights and degraded stopping ability. The failed components are available for inspection. The problem has now been confirmed by a Toyota dealership. The issue was reported to a Toyota dealership during the prior support-program period but was not confirmed then.

Abs break actuator and abs pump failed while driving losing loss of breaking. Toyota is aware of this problem but refuse to fix this notorious and dangerous problem they have with multiple model years. I was not informed of the limited service campaign. This should be recalled as a safety to the public.

Brake failure during operation due to bad brake booster pump and accumulator.

Brake booster failed while driving down the mountains back from big bear. Nearly wrecked several times, had no idea why my brakes weren't working properly. Go to autozone to scam the code, and I got the dreaded abs failure. Sadly the extended warranty for this known issue from Toyota conveniently expired 2 weeks before the failure. Toyota should be held accountable and pay for my repair, that o did myself. Parts cost me $1800, plus a day off from work I had to take. Atrocious situation, Toyota should be ashamed.

Toyota hybrid brake problems 2015 Toyota Prius I took to my dealership jim ellis Toyota in mcdonough GA. I was told that my brake master cylinder & brake booster pumps vehicle has failed. I experienced my brakes locking up, causing the vehicle to unexpectedly lunge forward or failing to engage when the brake pedal is depressed. On [xxx] my abs, brake, traction lights came on out of nowhere. I tried taking it to my dealership in April to jim ellis, Toyota of mcdonough for the lights, the one lights being on. I took it there around 8 o’clock in the morning and then there was a very rude and disrespectful service person by the name of victoria who told me that they would not be able to see me and told me that I needed to leave because I didn’t I have an appointment. This is a dealership that I purchased this car phone in 2018 and I have been taking my car to jim ellis Toyota of mcdonough since 2018 to get regular oil changes and other maintenance for my car. Such as things my brakes replace my front and the back brakes have my battery please and come several times out of the year to get a oil change because I have part of what they consider a lifetime oil change on my car. Also, I had a warranty whole time that I have been taking my car to the dealership they never once brought to my attention that there was a known recall for the brakes booster. It wasn’t until I took my car to dealership on Friday 5/30/25 that I was advised that this was a known issue for 2010-2015 Toyota Prius jim ellis dealership knew about the problem and failed to make repairs when I spoke with general manager lorenzo smith he advised that past the recall timeframe and my warranty has expired. Jim ellis dealership knew their were known issues and hid the issue I refuse to write the wrong by making the repairs to my vehicle. They’re trying to charge me over $3200 in repairs when I spoke with the general manager, he advised me that they didn’t make the repairs because my vehicle VIN number. Information redacted pursuant to the freedom of infor.

I own a 2015 Toyota Prius, purchased new and put in service December 4th, 2014. Car is well maintained. On may 10th, 2025 the brake booster pump and assembly failed. Has internal leak. I had the dealer confirm this. Lights on the dash, computer code c1391 ( abnormal leak in accumulator, rec replacement of brake booster and pump) and brake booster pump is pumping every 3 seconds from internal leak. Brakes are now at 50%. Soft. The pads and shoes are perfectly fine. It’s the brake booster pump assembly. Toyota issued instead of a recall, which would have been the right thing to due considering its long history of these over multiple years failing, just a customer service letter. 10 years or 150,000 miles, which ever comes first. Mine failed at 10 1/2 years. Now I am stuck with a $3,000 bill which I can not afford, to replace the brake booster pump and assembly. Toyota completely knows of the issue and side stepped having to issue a recall on this very well know problem.

Left our house and as we were driving out of our neighborhood the abs and brake lights came on. We looked it up in our book and couldn't find anything concrete to go on. Drove straight to auto zone and their test came back most likely brake booster or master cylinder. While looking it up, we read several stories people had posted saying this was a defect with 2012 - 2015 Toyota Prius' and to write to you and tell of the incident. I put my VIN # in and it doesn't show any recalls about this. Any feedback would be helpful. Thank you!.

Car feels like it lunges forward while braking over bumps. I have learned this is a known manufacture defect with the brake booster and brake actuator which Toyota is refusing to replace outside of 10 years from manufacture date. This is a critical safety item and failure can result in loss of brake power. Most owners do not know this part even exists until failure has happened already.

I was driving down the road when I noticed my brakes were not working. I had to push a lot harder on the pedal to slow the car down luckily, I did not crash into the car in front of me. I pulled over to see numerous lights on the dash such as traction, abs, and brakes. I had the car towed to Toyota where they quoted me almost $3000 to fix the brake accumulator and booster assembly. They said my car is outside the extended warranty of this problem. My car is a 2015 Prius with 154k miles. I found online that these things fail commonly on this generation of Prius. It's horrible for this company to charge us basically the cost of the car to fix the brakes.

Brake booster and master cylinder failed. Traction control and abs lights came on while driving. Upon inspection there is an issue with the brake booster and master cylinder. This is an issue that Toyota is aware of and were repairing under a customer service campaign. They are aware that these parts malfunction and instead of recalling them, they set expiration dates for free replacement. The car must be experiencing an issue and throw the correct code within the campaign window to be eligible for complimentary repair. The brakes failing in this way could cause great harm to me as a driver and others on the road making it imperative that I pay thousands in repair cause to ensure everyone's safety, though that is Toyota's job.

Brake booster failed on 2/11/2025 its a known safety issue with Prius 2015 models. I took car to Toyota for repair. They told me it needs to be replaced but out of warranty as this cr was produced in oct 2014 this is a major safety item. I took it in for 100000 miles check and it was not replaced then and now they are saying it is too late.

The abs and traction light appeared on the dash while driving on the freeway. I attempted to brake, while merging to exit but the car brake system did not respond. Luckily there were no cars close to us. Figured it could be a brake fluid problem so I added more fluid and it went away for a bit. It’s come back again and my car feels unsafe to drive. The brake pedal feels stiff or sometimes mushy like dough. I am waiting to get a diagnosis on my car but from what I’ve read and what other Prius owners are reporting, it appears to be the “break actuator and break booster pump” that is failing to work properly. Wondering if any other Prius owners have filed a complaint.

The contact owns a 2015 Toyota Prius. The contact stated that while driving at an undisclosed speed, the abs and the traction control warning lights illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with a leak in the brake fluid hose. The contact was unsure what repair was performed, but the vehicle was repaired. The contact stated that the failure reoccurred with an abnormal sound. The vehicle was taken back to the independent mechanic, and the contact was informed that the vehicle needed to be taken to the dealer for a complete diagnostic test. The vehicle was taken to the dealer, where it was diagnosed with brake booster failure. The contact was informed that the brake booster needed to be replaced. The vehicle was not repaired. The contact was notified of customer support campaign: zjb; however, the contact was informed that the repair was not covered under the customer support program because of the 10-year 100,000-mile limitation. The manufacturer was made aware of the failure, and a case was filed. In addition, the contact stated that the customer support program: zjb, was mailed out to customers 10 years ago. The contact stated that the information was never received. The failure mileage was approximately 114,000.

Brakes failing while driving in the rain. I was unable to use my brakes in the rain and headlights turned off while driving too. Took it to the dealer and they won't do anything unless lights are on on dashboard to read the code.

Bad break booster and was told I can’t get it repaired under the replacement program because it has to many miles! however I purchased my 2015 Prius used that had over 100 k already never received no notice from manufacturer or the dealer I bought the car from this is not fair and if Toyota is putting in faulty brake boosters, they should be replaced for free regardless of the mileage because I didn’t break the booster it’s the brake booster that was originally installed by the manufacturer! someone needs to do something, especially if it’s not the car owner‘s fault it’s the manufacturer fault for installing faulty parts! I need my car as a single mother I can’t afford $2000 for repairs and labor.

On the morning of December 11th, 2024, the brake system warning light (abs, yellow) illuminated on the dashboard along with the red brake indicator and the yellow vehicle stability control (vsc) system light. I consulted a mechanic who performed a computer diagnostic and informed me that the abs module booster had failed. He said that will order the part to change it but meanwhile he advised me to drive more cautiously and maintain a greater distance from the vehicle ahead, allowing extra space for my car to stop due to the increased braking distance caused by the failed abs module booster. Later that day, at approximately 5:30 pm, I was driving home in heavy traffic, with speeds not exceeding 40 miles per hour. The vehicle in front of me began to decelerate abruptly. When I applied firm pressure to the brake pedal to slow down my car, it lost all control. The vehicle began to skid, with the amplitude of the skid increasing progressively. It struck the highway guardrail on the left, changed trajectory, crossed all four lanes to the right uncontrollably, and ultimately collided with the highway guardrail on the right side.

There is a known brake booster issue with the Toyota Prius. They extended the coverage to 150,000 miles. My car is at 127,000 miles and they said the repair isn't under warranty and will cost over $3,000 to fix. There was no pre-warning lights or information received about this repair notice. I only noticed this when the lights came on and our abs lights went out. When I took it in they said I missed the deadline by 5 days, that I would have had to let them know by 11/20/2024. Which is insane for such a huge issue when I am well under the mileage coverage.

"abs actuator and brake pump - remove & replace - hydraulic booster assembly" -high voltage auto llc bakersfield, CA actually scared for my life when driving now. Brakes are now limp, constant sound of actuator cycling, code is c1391 problem is reproduced by dealer and independent service. Yes parts were inspect by manufacture. There are multiple warning lamps, actuator cycling is constant piror to lamps finally indicating issue.

Abs/ brakes, traction control warning lights came on 5 days ago. Dealer stated dtc 1391 code detected and recommend brake actuator replacement and brake booster assembly. Toyota issued TSB 0024-19 for service.

As many others have reported, the brake accumulator has failed. The symptoms began at 100,000 miles. When reported to the dealership, was brushed off as not a safety concern. It is, indeed, a major safety concern. My partner had the abs lights come on and brakes freeze up while driving on a fast and congested highway. Furthermore, getting this repaired is nearly impossible. The only Toyota dealership in town is estimated a $5k price. And since independent shops often cannot perform this repair, there is no comparison possible. They simply push to buy a new vehicle instead of standing by one that should be operating normally. The dealership is miracle Toyota of north augusta SC. Consistently does not support the consumers concerns and simply pushes repurchase as the only reasonable avenue. This is a known issue for Toyota that has stranded many of us without the ability to keep this car on the road. Please resolve with reasonable repair options due to faulty design.

Unknown brake issues.