Service Brakes Problems of Toyota Prius - part 1

Codes c1256 and c1391 acc low pressure and abnormal leak of acc press.

See all problems of the 2004 Toyota Prius 🔎.

The ads, traction light, and brake light all came on at once. Apparently this is a known problem with these cars and Toyota was fixing them for awhile but has stopped. No brake issues were reported when I brought it in for inspection in 2023. I never received any mail stating that this was a know defect and I needed to bring my car in to get it inspected. It's obvious to me that Toyota designed a defective part that impacts safety, and is forcing the owner to bear the cost of the fix by creating parameters that can never be met before the warranty expires.

See all problems of the 2014 Toyota Prius 🔎.

My brakes consistently lock and the car lunges forward. Driving down the highway I tapped my brakes and they didn’t work. I lost traction in the brakes. I had no control over the car or speed. I’m scared everyday I have to drive it. This is extremely dangerous and I've seen this comment often with this vehicle. Toyota said they had an extended warranty for this but it expired. I never received any mail or phone calls stating that this was a known defect. They say they can’t do anything now and are quoting me over $3000 to fix it.

Got the warning code for c1391 for the brake booster. It failed at 140k miles but because it failed past the 10 year mark did not qualify for the Toyota extended warranty program. I don't think the warranty program is good enough and should be addressed as a recall. I had sudden total brake failure on the highway which could have been extremely deadly.

See all problems of the 2015 Toyota Prius 🔎.

The Toyota brake booster system failed and is no longer safe to be on the road. The car will no longer brake properly and is a danger to anyone else on the road. It was inspected by Toyota prior. The entire dashboard warning lights for the brake system lit up 2 years ago and has fully failed now.

See all problems of the 2013 Toyota Prius 🔎.

2012 Toyota Prius. The brake system malfunctioned and my daughter was almost in a wreck. The abs, traction control, and brake warning lights on the bashboard all illuminated at the same time. The brake pedal feels soft and is less responsive requiring more effort to stop the vehicle. The brake actuator assembly is making a hissing noise. Ran a abs test using a scan tool and received a c1391 error code. The code points to a leak within the brake actuator system. Upon research I have found that this is a very common and costly repair that Toyota has known about for many years. Toyota issued a customer support program related to this issue that ran for 10 years or 150,000 miles from the vehicle's date of first use. This car, being a 2012, is beyond the support program. I contacted Toyota, hoping they would do the right thing and cover the repair. I was told that they would not cover the repair or supply the parts to cover the repair. I told the rep. For Toyota that I did not feel like it was fair for Toyota to continue to put millions of drivers at risk for a product that they clearly realize for years now is defective and could hurt or kill someone. The code and the braking issue did not appear until after the customer support program ended and therefore we had no warning or way to anticipate this braking issue or the danger to my daughter and anyone else riding with her in the car or on the roadway near her travel routes. I traveled 300 miles, rented a uhaul car tow trailer and brought the car back home. My mechanic confirmed the code c1391 and the fact that the brake actuator has failed. The mechanic has ordered the parts (the same defective parts) to replace the broken ones. Toyota is still selling the same part as a replacement part clearly knowing that it is not safe and no warning came with the replacement part explaining the potential for a braking issue. Based on internet research this same part is in many 2005 to 2013 Toyota and Lexus.

See all problems of the 2012 Toyota Prius 🔎.

Upon inspection, our mechanic determined that the master cylinder assembly and the actuator assembly require replacement (error code c1391). It is currently available for inspection, but will need to be repaired soon. Our safety and the safety of others is at great risk, because there is impending brake failure if driven and the end result could be catastrophic. On 09/13/25, the brake, traction control, abs and ((!)) lights came on about 10 minutes from home. We drove home, parked the car and did not drive it again until we took it to our mechanic on 09/15/25. During this incident, the brakes failed to respond properly, which could have led to a serious accident. We took the car to a local mechanic and repairs are currently pending. The estimated cost for the necessary parts is approx. $3,000 and the labor costs are estimated to be between $1,100 and $2,000. Our local Toyota dealership was also contacted and they confirmed the presence of code c1391. Please reference Toyota service bulletin pol18-03, which addresses issues related to the braking system in certain Toyota models, including the Prius v. This bulletin indicates that various brake system-related warning lamps may illuminate due to internal malfunctions within the brake system, and it outlines affected parts that may require replacement. Additionally, please reference Toyota customer support program 20te07, which provides extended coverage for certain brake system repairs. It is concerning that, despite this well-known, very serious problem, Toyota has not issued a recall. While our vehicle currently has 116,975 miles, we are aware that the warranty period ended 10 years from the first date of use or 150,000 miles. However, this malfunction not only endangers our safety, but also that of other drivers on the road. We urge the NHTSA to investigate this matter thoroughly and consider the implications for a potential recall for this model, because Toyota is well-aware of this issue.

I turned left into a parking space in my 2020 Prius. I stepped on the brake, and my car shot forward. I couldn't stop it, and it hit a concrete pole. It only took 1 second. It seems Toyota hybrids are still having this unintentional acceleration despite a multi billion dollar law suit in the early 2010's. My car was towed and is awaiting inspection by my insurance company. [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2020 Toyota Prius 🔎.

I have a 2013 Toyota Prius with 164,000 miles. A mechanic confirmed that the master cylinder and brake booster are failing and are not covered since warranty expired 14,000 miles ago. I have heard this is a common issue with this vehicle. Traction light, brake light and abs light are all on. The earring lights go on and off.

My 2022 Toyota Prius (approx. 12,500 miles) suddenly displayed multiple warning lights while driving, made abnormal noises, and lost the ability to move. The vehicle remained powered on but could not drive and had to be towed to a Toyota dealership. The dealer diagnosed a failed brake booster with master cylinder assembly and quoted ~$4,230 for repair. This is a safety-critical component that should not fail at such low mileage. Toyota has previously acknowledged premature brake booster failures in earlier Prius models (2010–2015) and issued customer support program pol18-03, extending coverage to 10 years/150,000 miles for the same component. I believe my 2022 Prius experienced the same type of defect, but Toyota refuses assistance. A sudden failure of the brake booster system while driving poses a serious crash and injury risk.

See all problems of the 2022 Toyota Prius 🔎.

When test driving the vehicle I asked about this buzzing/ whirring noise while sitting in the running but parked car. I was told these cars are hybrids, the electrical components make all sorts of whirring and humming noises and not to be concerned. Over the years I heard this noise, increasingly more and more, but I never knew it was something to pay attention to. Fast forward to July 2025. I noticed the car is inching forward while I’ve been stopped for a while at a red light almost like the brakes don’t want to hold. This has been happening so often that I have began to put the car in park while waiting for lights to turn green because it gets painful having to push the brake so far down. I take my car to a mechanic, explain all of the noises and the sensations and two mechanics drive it but say it feels fine and there are no recalls. They say my front brake pads are low and that must be what I’m feeling. After replacing the brake pads nothing had changed. Now there is also a squeak while moving at a slow speed in stop and go traffic. 1 week later I bring it up while getting an oil change and ask if they know what it could be. They said brakes seemed fine. A couple weeks go by and yesterday while I was driving down the highway in heavy school traffic out of nowhere my car makes a clunk noise and all of these lights pop up on the dash. I roll the windows down and scream for my children to hold on because something was wrong. Luckily we were able to get to safety but I definitely had reduced breaking capabilities. I immediately take the car in and and find out my brake booster and accumulator has failed. Service tech brings up the consumer program but my car is a 2013 and it is not eligible to be repaired bc it’s 10+ yrs. Even though Toyota admits to internal malfunctions of the brake booster assembly, and my car is only at 76,000 mi it’s not being fixed. This is negligence on Toyotas part. Not fixing these faulty parts is endangering lives.

I have a 2014 Prius v with 92,000 miles. My anti-skid, brake and abs idiot lights went off approximately 1 week ago. (August 25, 2025) scheduled an appointment at my Toyota dealer (September 3, 2025) and was told there was an abnormal leak in the accumulator and that the brake booster pump and brake pump assembly needed to be replaced. Cost $5715. Not related to the brakes, but they also said I had to replace the rear shock absorbers as they are leaking and needed to be replaced and then realigned. Cost $1363. This should have been a recall not a mileage or 10 year limit.

I have a Prius v 2012, and the lights for abs turned on and when I checked on internet Toyota was repairing the part for 150k miles and 10 years but this is a safety feature my car is now at 149922, and while I was on road suddenly the signs came up and I the brakes were hard, and this is a problem for my safety and for others too since it doesn’t brake well.

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.

The abs, brake, tsc lights have all appeared on the dash. When running the obd codes, the error c1391 appears indicating a problem with the abs pump. When under the dash with the vehicle running, one can hear the abs pump engaging every few seconds which is not normal. After resetting the code. The error quickly pops back up. This is a known problem with this model Prius that Toyota is aware of. Toyota has not put out a safety recall for this issue. They refuse to make the repair of a faulty designed abs module, which is obviously a safety concern. The vehicle currently has 128000 miles with no other issues.

See all problems of the 2010 Toyota Prius 🔎.

I was driving normally, about 30 mph in a residential area and the brakes all of sudden became soft. It was very scary and I didn’t know if it was safe to drive the vehicle. The brake, abs, and traction control sign all came on at the same time. I scanned the car and it was a c1391 error code. The Toyota dealership said it is not covered under any recalls. I called Toyota and asked about the zjb program that covered the repair but they said it expires. Toyota has a repair program for the defective part but no longer covers it. This issue is a known manufacturing issue and it’s dangerous. Toyota should cover it free of charge.

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.

Failed brake booster, pump, fluid, and actuator on my Toyota Prius 2013 with 143,972 miles on it.

The brake actuator failed, it can be available for inspection anytime. My abs light, brake light, and traction control lights all came on to indicate the failure. Since the hybrid engine requires the breaking system to recharge, failure of this part will eventually lead you to be stranded if it isn’t functional. Additionally, the responsiveness of the breaks makes driving at higher speeds a lot riskier. Toyota offered an "extended warranty" to have the parts replaced for free for 10 years or 150,000 miles, whichever came first. My make is 2014, at only 89,000 miles.

Brake booster, abs controller, and brake booster pump have failed for a second time. Parts replaced with new, in box from aftermarket dealer. Dealer/manufacturer refuses to accept that there are design flaws and will not recall.

When I’ve hit a pothole or hit the breaks to hard by abs, and traction control lights would come on and then turn off. The other day they all turned on and stayed on with the break light on as well. Breaks all seemed to work fine, just a little spongy. I brought it in to a shop and they estimated 3k to repair remove, replace, calibrate, and bleed abs accumulator assembly and brake master cylinder assembly. Test drive-new oem Toyota parts. These parts were recalled but only up to 10 years or 150k miles. I’m at 164k so ineligible for the recall but if this part completely failed while I was driving I could have been killed or caused someone serious harm.

Toyota issued a customer support program zjb for extended coverage of the brake booster and actuator assembly (this notice was not sent to the correct address the car was registered to with the dmv in 2019 so I never received the notice for this program) the Toyota program length was for 10 years or 150k miles. My car’s part just failed at 129k which is far below the 150k threshold. Despite being outside the 10 year window I am still under the mileage, the car is in perfect condition and this car is used for work for uber. The malfunction of the Toyota part in my car is a critical safety issue and because it is outside of the program Toyota refused to provide any goodwill assistance.

See all problems of the 2011 Toyota Prius 🔎.

I own a 2012 Toyota Prius c with approximately 156,578 miles. The vehicle has been diagnosed with c1391 – abnormal leak in accumulator, which causes the brake actuator to lose hydraulic pressure. This results in frequent buzzing from the actuator pump, illuminated warning lights (brake, abs, traction control), and loss of abs and stability control. The condition increases stopping distance and creates a serious safety hazard. Toyota previously acknowledged this exact defect under customer support program csp 21te01, which covered brake booster and pump assemblies for certain Prius and Prius c models when codes such as c1391 were present. However, the program expired on November 30, 2022, and my vehicle is just over the 150,000-mile coverage limit. Despite this, my Prius exhibits the same defect that Toyota has already recognized as a safety-related issue. Toyota carlsbad confirmed the diagnosis and quoted $3,399. 55 plus tax for repair, with a reduced courtesy estimate of $2,817. 86 plus tax, but declined goodwill assistance since csp 21te01 expired. Given the widespread reports of brake actuator failures in Prius models, I believe this represents a systemic safety issue that warrants NHTSA investigation and potential recall/extended coverage.

Abs failed and mechanic tells me my actuator needs replacement which is a known issue with my generation of Prius.

See all problems of the 2008 Toyota Prius 🔎.

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.

While driving on the highway, all the brake-related warning lights appeared on the dashboard. This was accompanied by a frequent electric buzzing noise (every 15-20 seconds, lasting two seconds each time). The brakes became difficult to press, almost spongy, and required more pressure to function. Upon taking it to the dealer, I was told that the vehicle (a 2013 Prius v with 181k miles) needed a new abs pump and brake actuator, totaling roughly $4100.

Have multiple warning lamps that light up on and off and the brakes in my car get spongy making the braking unsafe. The lights that turn on are the steering/ traction , brake, and abs light. There are multiple complaints online on youtube from similar issues ongoing and no recall made. My mechanic says it indicates a leak however there is no brake fluid missing and on youtube there’s work arounds because people keep getting the same message, yet no recall has been made. This can affect steering and cause an accident. Please recall soon. Including youtube link so you can see all the comments and issues from thousands that don’t know how to report but view to fix temporarily. [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Apparently Toyota knows of a recurring problem with the brake actuator. I took my Toyota Prius to the dealer for an unrelated recall issue that they repaired and I asked them what the sound was that I kept hearing every 10 seconds or so. The told me it is the brake actuator, but did not seem concerned at all that I get it repaired right away. They did quote me a very high price to have it fixed by them. I have chosen to take it to my mechanic for repair. In the mean time, I decided to research this on the internet and discovered that it is a known problem by Toyota and there is a class action suite filed on them. I want Toyota to pay to have it fixed! I fear for my life and lives of others with the same issue.

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.

Toyota has a break issue that they extended the warranty for 10 years or 150000 miles and now a few months pass the 10 years I have a problem with the actuator giving warnings and my daughter went into a skid when applying the breaks. She was lucky and didn’t hit anyone. If Toyota knows there is a problem that is a safety concern they should fix it I did get a Toyota dealership to give an estimate to fix it and was told $4300. 00 I think that’s too much for a defective part. It should be a safety recall.

Brakes have failed with a dtc c1391 indicating an accumulator leak. The brake booster pump constantly runs. When the dtc is triggered the brake feel becomes suddenly different as regen braking is lost. Appears to be a very common and expensive repair. Toyota has already had recalls and extended repair program for these parts but they are now expired and not covered.

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

I am experiencing the issue described in the brake booster and brake booster pump assemblies recall issued by Toyota for the Prius, which for me ended in 2023. The vehicle is unsafe to drive without performing this $4000 repair (dealer cost), which is almost more than my car is worth. Toyota should issue another extension for the repair coverage since they are known to be faulty. The previous recall and extension of the recall can be found here: [xxx] information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).