Toyota Prius v 2014 — Reported problems

Facing brake booster/accumulator leak at ~105,000 miles diagnosed and confirmed by a mechanic at an independent service center. Problem is characterized by a hissing and chirping sound from the brakes. No warning lights appear on the dash, but this is a known problem with the 2014 Prius. Brake system could fail at any time, preventing the car from stopping. Repair of this system requires a >$2,500 payment. Toyota had an extended warranty up to 10 years after the car was purchased or before 150,000 miles. In this situation, the problem showed up after this time (2026), preventing compensation for repairs.

ABS and brake light are on. was on the freeway and when i pressed the brake the wheels got locked and the car made a 360 spin, it almost flipped over

The vehicle is experiencing a critical failure of the Brake Actuator and Booster Pump assembly. The dashboard currently displays multiple warning indicators: ABS light, Traction Control light, and the Brake System Warning light (Master Warning "!"). Symptoms: Mechanical Failure: The internal high-pressure accumulator is failing to hold pressure. The electric brake booster pump is heard cycling every 10-20 seconds even when the vehicle is stationary and the brake pedal is not depressed. Loss of Braking Safety Features: The system has disabled regenerative braking and Anti-lock Braking (ABS), causing significantly increased stopping distances and a “spongy" brake pedal feel with diminished braking response. Predictability of Failure: This failure matches the exact symptoms described in Toyota's Customer Support Program 20TE07 (and previously ZJB), which acknowledges an internal defect in the brake actuator. Safetv Risk: The sudden transition from power-assisted braking to manual hydraulic braking during a drive creates an immediate safety hazard. As the pump motor continues to cycle excessively to compensate for the internal leak, it is at risk of total thermal failure, which would lead to a near-total loss of braking assist while the vehicle is in motion. Despite the vehicle having only 75,689 miles (well under the 150,000 mile limit acknowledged in Toyota's support programs), Toyota has declined to provide assistance because the vehicle has surpassed the 10-year age mark. Toyota is wrong in not providing support for vehicles whose critical components such as brakes shouldn’t experience catastrophic internal failure at 75,689 miles, regardless of the vehicle's age.

While driving my 2014 Toyota Prius, the BRAKE, ABS, and vehicle stability/traction control warning lights illuminated. There was no crash, injury, or noticeable loss of braking before the warnings appeared, and there were no preceding symptoms. The vehicle was evaluated by Mac Haik Toyota in League City, TX, an authorized Toyota dealer. They diagnosed DTC C1391, “Abnormal Leak of Accumulator,” and determined that the brake booster and brake booster pump/accumulator assembly require replacement. The dealer advised that the vehicle cannot be driven and is considered down. The vehicle/components are available for inspection upon request. My safety concern is that this is a brake-system malfunction serious enough that an authorized Toyota dealer has determined the vehicle cannot be driven. Toyota previously established Customer Support Program ZJB addressing internal malfunctions of the brake booster and brake booster pump assemblies in 2011–2015 Prius vehicles. Toyota’s documentation specifically identifies C1391 as a diagnostic code associated with this condition. My Prius has only approximately 102,000 miles, well below the program’s 150,000-mile limitation, but is outside its 10-year time limitation. The Toyota replacement part required to repair the brake system is now backordered with no known timeframe for availability. Because Toyota has advised the vehicle cannot be driven, it will remain out of service until the part becomes available. I am reporting this because a previously identified brake-system failure continues to occur after Toyota’s support period expires. I ask NHTSA to consider whether continued C1391 brake booster/accumulator failures in these Prius vehicles warrant further investigation or safety action.

I am submitting this complaint regarding a serious safety concern involving the brake actuator/booster assembly on my 2014 Toyota Prius. My vehicle has experienced failure of this critical braking component and has been unable to be properly repaired since November due to difficulty obtaining the correct replacement parts. This involves a major safety system required for proper braking operation. Brake actuator/booster assembly. Diagnostic codes: B1206, B2321, C1252, C1253 C1256. Toyota previously acknowledged brake actuator concerns through Customer Support Program ZJB. However, my vehicle is outside the program limits despite experiencing what appears to be the same type of failure reported by many other Prius owners. Since November, I have faced difficulty obtaining the correct parts, reports of nationwide backorders or limited availability, conflicting information regarding updated Toyota part numbers, and concerns about repair providers advertising new OEM parts that may actually be aftermarket or incorrect components. This creates a safety concern because owners experiencing brake failures may be unable to obtain timely repairs using verified, appropriate parts. Repair estimates have ranged from approximately $3,000 to over $4,000, including a Toyota dealership estimate of approximately $4,100. This creates a significant barrier to restoring a vehicle to safe operation, especially involving a component Toyota has previously addressed through a customer support program. I request that NHTSA review this complaint and similar reports to determine whether further investigation is warranted regarding Toyota Prius brake actuator failures, parts availability issues, and whether additional manufacturer action or support is needed. A vehicle’s braking system is a fundamental safety component. Owners should be able to obtain a safe and reliable repair without months of delay or uncertainty regarding replacement parts.

In 2024, I had my vehicle checked out prior to a road trip because the brakes were making "fart noises," and I was worried about driving it to Albuquerque. The AAA certified dealer I took the car to said everything checked out alright. I never received the letter regarding the brake system issue, so I could not take advantage of the extended warranty repair program. My car was in the 80-90 thousand mile range and had not yet rolled over. Fast forward to 2025, my dashboard lit up all over the place, and I got the brakes checked again. By that time, the fault code was coming up, but the entire ABS system needed to be replaced. I was unable to get any help from TOYOTA despite this being a KNOWN FAULT WITH TOYOTA PRIUS AND TOYOTA PRIUS V FROM THIS TIME PERIOD. They are STILL not doing anything to help their customers. Brake issues are EXTREMELY dangerous, and it is wildly negligent to continue moving forward WITHOUT fully recalling the ABS system in the FULL LINE of prius vehicles from the impacted manufacture dates. Every prius owner I know has had to deal with this. My care was UNDER the required mileage but PAST the dates to be repaired. PLEASE consider holding TOYOTA responsible and getting them to refund Prius owners who have already paid for this COSTLY repair out of pocket. Thank you.

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My car experienced a failing brake actuator/accumulator. The first sign was the ABS and break lights accompanied by a whoosing sound. The issue causes intermittent system wide break failure and renders the car undriveable. Toyota had an extended warranty for this issue but that offer was closed by the time my car had the failure even though it was still under 150,000 miles. I believe this is a significant safety issue and should rise to the level of a recall by Toyota.

Brake actuator had been making noises and it finally stopped working on 7/14/26. Thankfully my car was and stopped and parked. The car has 137k miles on it, one owner and no explanation of what caused this. There were no accidents, abuse, or failure to maintenance.

The traction control, abs, and emergency brake light came on. We checked and the code produced was C1391. There’s a humming noise every 10 or so seconds when idle. The humming noise is also present when braking. We did some research and this appears to be an issue with Toyota Prius. We called the dealership and were informed that this was not a known issue. Thank you.

I purchased a 2014 Toyota Prius V in 2013, and it currently has 120,000 miles on it. Last month, the engine light came on, so I took it to a dealership. They diagnosed the issue and provided the codes P0302 and P0304. After consulting multiple shops, all confirmed that coolant is leaking into the engine, which means I either need to repair the head gasket or replace the engine entirely. The quotes I've received for this repair range from $5,000 to $15,000, while the current value of the car is only about $5,000. I want to file a complaint regarding Toyota's responsibility for these engine issues. We buy cars because we trust the brand, and in this case, Toyota has broken that trust. Despite maintaining the car according to Toyota's recommended schedule, I have encountered this serious problem.

Car is at less than 105k miles and yet brake actuator is failing.

ABS, traction control, brake system, and brake lights turned on while driving. Took the car to the mechanic and pulled the code C1391. It seems from other complaints to NHTSA that it is a common issue and quite dangerous, meaning the brake system is failing.

ABS, brake, and traction warning lights came on. Loss of power brakes/limited manual brake. Extended warranty/customer service outreach did not apply. Car is at 120,000 miles and almost 12 years.

When the brake is applied, the vehicle accelerates for a fraction of a second before slowing down. I have experienced this when the vehicle is moving slowly, such as in a parking lot.

Description of the Problem Vehicle: 2014 Toyota Prius v (Mileage: 70,000) Problem Description: The vehicle is experiencing a critical failure of the Electronically Controlled Braking (ECB) system, specifically the Brake Actuator and Booster Pump assembly. The dashboard currently displays multiple warning indicators: ABS light, Traction Control light, and the Brake System Warning light (Master Warning "!"). Symptoms: Mechanical Failure: The internal high-pressure accumulator is failing to hold pressure. The electric brake booster pump is heard cycling (straining) every 10–20 seconds even when the vehicle is stationary and the brake pedal is not depressed. Loss of Braking Safety Features: The system has disabled regenerative braking and Anti-lock Braking (ABS), causing significantly increased stopping distances and a "wooden," unresponsive brake pedal feel. Predictability of Failure: This failure matches the exact symptoms described in Toyota’s Customer Support Program 20TE07 (and previously ZJB), which acknowledges an internal defect in the brake actuator. Safety Risk: The sudden transition from power-assisted braking to manual hydraulic braking during a drive creates an immediate safety hazard. As the pump motor continues to cycle excessively to compensate for the internal leak, it is at risk of total thermal failure, which would lead to a near-total loss of braking assist while the vehicle is in motion. Additional Notes: Despite the vehicle having only 70,000 miles (well under the 150,000-mile limit acknowledged in Toyota’s support programs), Toyota has declined to provide assistance because the vehicle has surpassed the 10-year age mark. I am filing this report because a primary safety component (brakes) should not experience catastrophic internal failure at 70,000 miles, regardless of the vehicle's age.

I have 2014 Prius v 5 with 100,000 miles but I had issues with brake booster pump

8/2025 Car stalled on freeway. Went to dealer. They said nothing wrong. Then on a trip north, car stalled again on freeway. Went to the nearest dealer. They too said nothing wrong. This time same thing. There is a recall for the exact symptoms of the exact car yet they say the repair was done. Why does my vin not qualify for the exact symptoms that generated a recall? This was super dangerous at freeway speed. Toyota knows there is a problem with the inverter and it's computer. Now I'm paying again for a diagnosis. That makes $750 just diagnosing and now if they actually decide it is the inverter, I have to pay upwards of $3000 even though there is a recall? What the heck?

On April 5, 2026, while driving downhill around a corner in my 2014 Toyota Prius, the brake booster and brake booster pump assembly failed without any prior warning. When I pressed the brake pedal the car did not slow down and instead appeared to accelerate due to a complete loss of braking assist. I was unable to stop the vehicle normally and had to rely on gravity and coasting to slow down, creating a serious risk of collision. There were no warning signs prior to the failure. Immediately after the incident, three warning lights illuminated on the dashboard: the BRAKE light, the ABS light, and the VSC (vehicle stability control) light, which have remained on since. The vehicle was taken to DARCARS Toyota Baltimore, 6007 Eastern Ave, Baltimore, MD 21224, where the failure was confirmed on April 15, 2026. Technician Victor Lawson diagnosed diagnostic trouble code C1391, which is the exact qualifying code listed under Toyota's Customer Support Program ZJB for brake booster and brake booster pump assembly failure (RO# XXX). The vehicle remains at the dealership and is available for inspection. Toyota corporate was contacted and opened case number XXX but declined to cover the repair despite this being a documented issue that Toyota has publicly acknowledged. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

While driving, three warning lights suddenly appeared on the dashboard . Abs warning, traction light, and break warning light At the same time, the brake pedal became very hard to press, and the vehicle did not slow down as expected. This caused a significant increase in stopping distance, and I nearly rear-ended the vehicle in front of me. The issue appears to involve the braking system and created an immediate safety risk. No prior warning signs were noticed before this incident. The vehicle has not yet been inspected but is available for inspection upon request.

The brake booster has failed and seems to be a common issue with this model vehicle for Toyota issued an extended warranty, but I am passed the date and they are unwilling to do anything. Due to the malfunctioning brake booster. The car is unsafe to drive the too expensive to repair.

Subject: Brake Booster/Pump Assembly Failure – Toyota Program ZJB / 23TE07 Description of Incident: I am reporting a failure of the brake booster and pump assembly on my 3rd Generation Prius (82,000 miles). While the vehicle is 11.3 years old, it is well under the 150,000-mile threshold of Toyota’s Customer Support Program ZJB. The brake pump began cycling every 13 seconds, indicating an internal pressure leak in the accumulator. This is a documented precursor to a total loss of power-assist braking. Despite the clear mechanical failure, no warning lamps or Diagnostic Trouble Codes (DTCs) were triggered, creating a safety hazard where the system could fail without prior electronic notification. Repair and Cost Details: Because the vehicle was 1.3 years past the arbitrary 10-year "Secondary Coverage" window, I was forced to pay $3,461.18 out-of-pocket for a known manufacturing defect. I would like to highlight a discrepancy in labor billing: while Toyota’s own technical bulletins (ZJB/23TE07) state the repair should take approximately 5.3 hours, the dealership charged 8.9 hours of labor for the same procedure. Safety Concern: By limiting coverage to 10 years, Toyota has left many low-mileage owners with a critical safety defect that degrades over time regardless of mileage. I request that the NHTSA transition this from a "Customer Support Program" to a formal Safety Recall to ensure all affected vehicles are repaired and owners are reimbursed, regardless of the vehicle's age.

the cylinder head gasket blew because of the poor design of the intake manifold and the EGR system. There are updated parts to fix this issue, but there was no recall. This poor design led to the vehicle having "the Death Knock." It started doing this knock on my trip driving my daughter to college. The engine could have seized in traffic on the way to [XXX] from [XXX] . No warning lights came on telling me there was an issue. The vehicle is being taken apart now to see if my connecting rods were bent from the coolant entering the combustion chamber. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The contact owns a 2014 Toyota Prius. The contact stated that while driving at an undisclosed speed, the vehicle failed to slow down as intended with the brake pedal depressed. The ABS warning light was occasionally illuminated. The vehicle was pulled over to the shoulder of the roadway and restarted. The vehicle was taken to a local independent mechanic, where it was diagnosed, and determined that the brake master cylinder, brake booster, and brake lines needed to be replaced. The local dealer was contacted; however, the vehicle was not diagnosed or repaired. Upon further investigation, the contact related the failure to an undisclosed recall; however, the VIN was not included in the recall. The manufacturer was notified of the failure. The contact was referred to the NHTSA Hotline for assistance. The failure mileage was approximately 152,000.

Vehicle: 2014 Toyota Prius v Hybrid Mileage: 79,000 miles The vehicle experienced sudden failure of the brake booster / brake accumulator system. Multiple warning lights appeared including ABS, traction control, and the red brake warning light. Diagnostic code C1391 was retrieved. The brake pedal became soft/spongy and the electric brake pump began cycling frequently. Braking performance felt reduced and inconsistent, creating a potential safety risk. This vehicle has very low mileage (79,000 miles) and has been well maintained. The failure appears to be related to a known defect in the Prius braking system. Toyota previously issued Customer Support Program 20TE07 addressing brake booster and pump failures on 2012–2014 Prius v vehicles. Despite this known issue, the repair is not being covered and the cost quoted is several thousand dollars. A failure of the brake booster/accumulator system significantly affects braking performance and should not occur at this mileage. This appears to be a widespread issue affecting Prius vehicles and represents a potential safety defect involving the braking system.

Head gasket failure. No check, engine, light or warning. My car was very well maintained regularly. After research, I found this to be a very common problem. Yes it is available for inspection. Upon request. The problem was confirmed by chemical test, ignition vapors going into engine coolant. Other symptoms were misfiring on cylinder two and cylinder four. Severe engine knocking.

Brake booster is not working

The brake booster/accumulator failed on my vehicle. This part was a common failure during the 2010-2015 production run so much so that Toyota extended coverage to replace. Mine failed recently beyond the warranty extension of 10 years/150k miles. My vehicle has only 108k miles and is 15 months beyond warranty. Toyota Corporate will not replace this vital part, despite the fact it was a defective design. I can’t drive it any longer since I don’t have the $4000 to make repair. Toyota Corporate has shown little concern despite this critical safety defect.

The slip notification, abs, and brake lights turned on while driving on the highway. The brakes then became very stiff and the vehicle did not brake as fast or as well as it normally does without the lights.

2014 Prius HB with 135k miles , onboard system warning lights for Brakes, ABS system, TPMS and Traction Ctrl all came one suddenly. Brake losing pressure while vehicle making strange noise under front driver side

On Jan 5, 2026 I was driving locally at about 40-45 mph. All of a sudden 3 indicator lights came on ABS, Brake, and Brake System Warning Light. There were no noises, but the brakes felt different. They did stop when needed. I left space between myself and others just in case, did not want an accident. Called my regular mechanic. They advised to not drive the car, but to bring it into the shop at 8am the following day. On Jan 6th, the mechanic stated it was beyond their expertise. It was towed to the local Toyota Dealer for repairs. It ended up being the Brake Booster and Pump. Upon investigation online, we saw this was a recall, but we were not notified by Toyota.

I was driving on the freeway, and a few lights(including ABS, brake lights) all came on and a beeping noise started, as i immediately lost complete control of my brakes! That God it was late, and no cars were in front of me. The car slowed down as I removed my foot of the gas right away. I tried to pull over as soon as I heard the lights, and that’s when I realized my brakes were completely gone! I was able to stop after about two miles; car stop on its own as it slowed down. Apparently, this was a major known issue and had warranty up to 150k miles. At the time of the incident, my car had about 165k miles. I had the car for years, and no one at the dealer ever mentioned anything about this or even tried to make me aware of it! I called the Toyota dealer and corporate number several times and they declined providing me with any help at all! This caused me fear and traume because I never thought this was possible! It could’ve ended my life and the life of people around me if there were any cars in sight! The problem has been confirmed by a reputable mechanic! He did the repairs! He also called the Toyota dealer and corporate and attempted collecting anything since he found out about the warranty and common issue. They also denied help. No lights were on at all before this incident happened! It all came at once! I even have all records of monthly/ bimonthly complete inspections at the dealer with everything normal on the results!

Hello, We were informed that the vehicle paint had a recall due to paint chipping. Unfortunately we never received the notice and was unaware until after the recall program had ended. We are contacting you now to see how we can address this issue as our vehicle paint is chipping all around the car.

The brake booster system (electric brake booster pump) in my 2014 Toyota Prius has been making frequent, audible cycling noises inside the cabin, particularly during cold weather. I have also noticed a faint odor outside the vehicle that seems related to electrical movement. No ABS or brake warning lights have illuminated, but the cycling pump may indicate increased stress on the brake system. The issue has not yet been diagnosed or confirmed by a dealer or independent service center. The problem has not caused a loss of braking ability to date, but the unusual noises and electrical odor suggest potential risk if the booster were to fail completely. No recall or customer support program currently covers this issue. The component is part of the vehicle’s brake system and would be available for inspection by a dealer or manufacturer upon request. Toyota has offered no help or possibility of Goodwill assistance inspection for this issue.

The brake system malfunctioned suddenly. While driving and while stopped, the brake pedal became very hard and braking behavior became unpredictable. The vehicle sometimes brakes aggressively and other times requires excessive pedal force to stop. The ABS and BRAKE warning lights illuminated. The vehicle no longer provides normal braking assistance. This issue is related to a failure of the brake actuator / brake booster, which is a known issue affecting Toyota Prius models from 2010 to 2015. This defect creates a serious safety risk, as braking performance is inconsistent and may increase stopping distance or cause loss of control during emergency braking situations. The vehicle has not been repaired yet because the cost is very high and the manufacturer has declined assistance despite this being a known safety-related defect.

misfire code along with rough starts/light load. T-SB-0116-15

The contact owns a 2014 Toyota Prius V. The contact stated that while driving approximately 35 MPH, the brake light, tire pressure, traction control, battery, and other warning lights were illuminated. While attempting to depress the brake pedal, there was more resistance than normal, making it difficult to slow the vehicle. The contact was able to drive the vehicle to the nearest mechanic; however, the vehicle was not diagnosed. The vehicle was then taken to the residence. The vehicle was taken to another certified mechanic, who diagnosed and determined that the brake master cylinder and actuator assemblies had failed. The brake master cylinder and brake actuator assemblies were in the process of being repaired. The manufacturer was not informed of the failure. The failure mileage was approximately 220,000.

My 2014 Toyota Prius (VIN [XXX] , 77,000 miles) displayed Brake, ABS, and Slip warning lights. A mechanic confirmed failure of the Brake Booster and Pump Assembly (DTC C1391). Toyota previously acknowledged this as a safety-related defect under Customer Support Program ZJB, but my coverage expired because I never received Toyota’s notice dated May 21, 2019. My car has been undrivable for weeks and Toyota refuses goodwill repair. This is a serious brake safety issue that should be reviewed for recall or extended coverage since many Prius owners have experienced the same failure. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ABS complete and total failure while driving.

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.

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.

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.

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.

C1391 - Abnormal Leak of ACC Pressurization. Bad Brake booster assembly.

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.

The contact owns a 2014 Toyota Prius. The contact stated that the ABS and the traction control warning lights were illuminated. The vehicle was taken to the dealer to be diagnosed, and the contact was informed that the brake master cylinder needed to be replaced. The vehicle was not repaired. The vehicle was taken to a certified mechanic and was diagnosed, and it was determined that the brake booster had failed and needed to be replaced. The vehicle was repaired; however, one day later, both warning lights returned. The vehicle was returned to the mechanic and air was blown into the hydraulic valves and the other valves were cleaned; however, the failure persisted. The manufacturer was not informed of the failure. The failure mileage was approximately 150,000.

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.

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.

I was told that my Brake Booster and Brake Booster Pump Assembly needed replaced. I had specifically asked my dealership in the past if there were any issues with my car and was told that there was nothing, which was untrue. I called Toyota and was told that I was mailed something back in 2018, but I do not remember receiving it. Now I am told that this has expired. I wanted to know if I had any recourse or extension time on this program 21 TE01. I am afraid that my brakes will not work, as the lights go off and on. [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

There was a safety recall issued for brake system malfunctions involving the brake booster and brake booster pump assemblies on my vehicle. Unfortunately, the recall expired on December 31, 2024. On March 4, 2025, at 4:10 PM, I contacted the District Manager Advocate in Plano, Texas. I explained that I had been in the ICU twice and am now [XXX]. During the recall period, I was in and out of hospitals for more than four years, making it impossible for me to be aware of or respond to the recall in time. My vehicle has since begun exhibiting the exact symptoms outlined in the recall. When I brought this to their attention, I was told that while the issue was indeed covered under a past recall, there is nothing they can do now because it has expired. This vehicle is our only mode of transportation, which is critical for my ongoing medical treatments, as well as for my husband who recently suffered a heart attack. As I write this, we have no other option but to continue using the vehicle—despite the serious safety risk—because of the urgent and necessary care both of us require. On August 4, 2025, I contacted Toyota headquarters. They reached out to the dealership and spoke with management, but unfortunately, no resolution was offered except for information about a separate, newer recall. I followed up again with the District Manager and spoke with Ashley, who informed me that after escalating the case, there was still nothing further they could do and she expressed her apologies. This situation has caused further deterioration to my health due to the stress and anxiety of potential vehicle failure, and it has added to the burden of my husband’s fragile health condition. At this time, he has been unable to return to work, and we have no income to cover the cost of a repair that should have been addressed through the original recall. We would deeply appreciate any assistance, reconsideration, or compassionate review of our case. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

ABS Brake pump actuator booster failed. It is available for inspection. While driving, I started hearing a hissing sound from my brakes. I tried to slow down and my several diagnostic lights (ABS, traction control, brake, check engine, etc.) flashed on while my brakes failed to work properly. I turned on my hazard lights immediately. I was in the middle of the road with my toddler in the car and I almost rammed into the car in front of me. Luckily I was able to pull into a turn lane and pushed with all my might on the brakes and it finally was able to stop. My brakes failed and I could have hit the cars in front of me and hurt my child, myself and others. It was terrifying. Problem has been confirmed by an independent service center. The warning lamps only appeared WHILE the issue was happening and my brakes failed to work properly.

The car stalls randomly and does not enter fail-safe mode. The dealer says it is the transmission but the transmission has never shuddered or hesitated. I am reading that these vehicles have intelligent power modules in the hybrid inverter that fail and can cause stalling. I feel like the dealership is working with Toyota to avoid addressing the actual problem. In the meantime I was sent home in a vehicle that continues to stall randomly and does not enter fail-safe mode.

Cruise Control Not Working. Traction Control Light Active, Brake Light Active, And Light Active The cause was diagnosed by Toyota of Paris. TSB for C1391 Code abnormal leak in accumulator. The corrective action is to replace brake booster assembly with Master cylinder and Brake Booster pump Assembly.

I am writing to express my profound concern and disappointment regarding a recent, terrifying incident involving the brake system of my 2014 Toyota Prius. On Saturday, June 21, 2025, while driving with other passengers, my vehicle experienced a complete and sudden brake failure. Multiple warning lights illuminated on the dashboard, and despite my efforts, the brakes became unresponsive, making it impossible to stop the car. The sheer terror and helplessness I felt in that moment, with the very real potential for a catastrophic accident involving myself, my passengers, and other road users, is indescribable. Fortunately, through sheer luck and quick thinking, I was able to make an emergency stop on the side of the road, preventing any collision or injury. However, the emotional toll of that experience, the lingering stress, and the fear of a recurrence remain significant. I was subsequently informed that the cause of the failure was a leak in the brake accumulator. I am attaching the diagnosis and repair invoice. The necessary repairs were not completed until Wednesday, June 25th. This unforeseen and critical malfunction also necessitated the expense of a rental car for four days, adding to the financial burden and inconvenience. My frustration is compounded by the fact that this brake accumulator issue is a well-documented and known defect in Toyota Prius models, specifically affecting 2010-2015 vehicles. Toyota itself has previously issued a Technical Service Bulletin (TSB T-SB-0043-13) acknowledging this problem and offering warranty extensions for affected vehicles, typically up to 10 years or 150,000 miles. Despite this being a recognized safety concern, I was informed that my vehicle falls approximately eight months outside the 10-year warranty period, thus disqualifying me.

See Attached Letter

While braking on the interstate, this car threw error code C1391: Abnormal Leak of ACC PRESS. This is the brake system accumulator pressure - meaning lost all assistance to braking - it took a long time to slow down and come to a stop. Easily could have caused a serious crash had I been on a hill or coming up on stopped traffic. I did some research and found this is a KNOWN ISSUE with Toyota and SHOULD HAVE BEEN A RECALL! Toyota skirted the issue by offering customers that encountered the problem a CUSTOMER SERVICE PROGRAM where they would pay for a new brake pump and master cylinder. HOWEVER, Toyota put TIME and MILEAGE CONSTRAINTS ON THE PROGRAM, and it just so happened our car had exceeded those limits - so we had to pay full price for the repair of the 2 new brake parts - over $3,000! The 2014 Toyota PriusV that we bought new and had always serviced it properly was hardly worth that, but it was our only car, so we paid it. BUT will never buy another Toyota now - and NHTSA needs to fine Toyota for this poor brake system

We were driving on a city street about 25-30mph and the car jerked suddenly and the lights on the dashboard illuminated and the "Check Hybrid System" message came up as well. The car was able to coast to a nearby parking lot. We attempted to drive the car home and the car stalled in the middle of the street. We were able to push the car off the road and then get it towed. The presented a potentially very dangerous situation as the car had a complete failure while driving in the middle of the road. The Toyota service department ran a diagnosis which returned DTC P0A94. All of this indicates that the car should be covered under the CUSTOMER CONFIDENCE PROGRAM 23TE03 however that program seems to only cover the 2010-2015 Prius and 2011-2017 Prius V models and not the Prius C. There are several reports of this same issue happening on the Prius C as well though so it doesn't make sense that it is not covered.

Upon exiting the highway my brake system when engaged was completely unresponsive. I of course pushed down gently as would and upon realizing the brakes were not responding I started pounding on the brake pad. I had to ram the brake down for the vehicle to even slow. Thankfully no-one was in front of me at the light and I was able to pull into the nearest gas station having to ram brake to fullest extent to get the vehicle to stop moving. All lights within the braking system lit up including the Master Warning Light, Brake System Warning Light, ABS Warning light, and SLIP indicator as well as the warning siren. These warning lights did not come on til after* the brake system was engaged with failure*** NOT PRIOR. It was not indicative of an issue prior too, no former brake issue or warning lights. I turned the vehicle off and then back on again to see if the same lights still lit and issue was still malfunctioning. I called for a tow and had vehicle taken to the Adams Toyota Dealership (MO)The following diagnostic code C1391 was registered on my vehicle at dealership. Upon research (not disclosure) I found that the above code- C1391- "Brake booster and Brake Booster Pump Assembly" is a known issue that Toyota offered a Warranty repair from May 21-Nov 22' IF FAILURE Not a recall but a "if" brake system fails. Please see Customer Support Program 21TE01. I purchased vehicle in OCT 21 and was never informed, never provided this warranty letter, issue didn't show up on Carfax etc and I purchased directly from the Toyota Dealership. Upon research you will find that Toyota is currently in class action and individual lawsuits re this specific part failure with the above diagnostic code. They are denying replacement due the expired warranty time. The Parts should recalled* not just a "warranty issue" -unacceptable to leave buyers uninformed to such a major issue that can cause accident/death (IM PREGNANT I MAY ADD!) and unable to seek covered repairs unless it fails!

The vehicle stalled while driving 35 to 45 mph. Engine had no power but the brakes and power steering worked.

While driving my 2014 Prius V it stalled. I turned it off and restarted it. The yellow car symbol with an exclamation point lit up. I turned the car on and off again. The light went away and I was able to drive home. I was unable to get any OBD 2 codes on my personal reader. I changed the 12 V battery and thought this had fixed the stalling. Then it stalled again and repeated the same process. Though we were able to drove the car I had it towed to a dealership for safety reasons. The dealership pulled codes, cleared them, drove the car 20 miles, and were unable to reproduce the codes. I was told to return when the codes returned. It stalled again and now I am afraid to drive this car.

After 120K miles and 11 years of use, my Prius 3 brake booster pump failed while I was driving. The warning lights came on, including the ABS and brake lights. My brake felt strange, and I had to finish my drive to the dealership keeping a large driving distance so the brakes would work in time. I was advised that this was a result of a C1391 error and that the brake pump part is only covered under extended warranty for 10 years. The advisors at the dealership said it is extremely common for cars to come in with this problem just after the warranty period has ended. I have spoken to other Prius user who have complained of the same issue and are considering a class action lawsuit because this safety issue is so common.

While driving my dashboard lit up with Brake, ABS, and traction control warning lights. Brake pedal fell to the floor when pressed. I was then able to stop the car. I brought the car to a local auto parts store, where they were able to determine that the error code was C1391 brake accumulator pressure leak. I made an appointment and brought my car to my local Toyota dealer the next day. I was informed that the brake booster assembly, brake booster pump, and master cylinder would have to be replaced, at a cost of approximately $4035.00. I was informed that Toyota issued a Customer Satisfaction Program for this exact issue on my car. While my car has 129,000 miles and falls within their coverage range of 150,000, the car’s age of 11 years did not fall within their limit of 10 years. According to Toyota, this is a known failure and my only problem is that my brakes did not fail sooner. Toyota’s corporate office denied my appeal to cover the cost of the repair. The local Toyota dealer charged me $150 to read the code and confirm what the local Auto parts store was able to do for free.

Issue started with a noise sounding like a motor constantly trying to prime its self. Then while driving on freeway ABS light Brake light and traction control lights all came on. Took car to dealership and was given a $3700 bill to replace Brake Booster Master Cylinder and Brake booster pump. This is a known issue to Toyota and have offered an extended warranty 10 years or 150000 miles but not a recall. My vehicle is at 11 years and 123000 miles. This issue put my family in danger due to the threat of total brake failure.

Was driving down the road and the brakes stopped working and the the brake light the traction light and abs light came on. The brakes only worked if i put the pedal all the way to the floor after that. I checked online and found numerous other people have had this issue but no recall has ever been done. only nhtsa safety notices and a volunteered customer support program by toyota which was no longer being honored because I was passed the 10 year mark even though my vehicle was still under the 150k mile threshold by toyota. I wish your organization would force toyota to do a full recall on this. this is a dangerous safety issue involving a defective brake booster and master cylinder

The contact owns a 2014 Toyota Prius. The contact stated while driving at an undisclosed speed, the vehicle failed to stop or decelerate as intended while the brake pedal was depressed. The ABS and service brake warning lights were illuminated. The contact added brake fluid; however, the failure persisted. The vehicle was taken to a local dealer where it was diagnosed; however, the cause of the failure was not yet determined. The vehicle was taken to a local Auto Zone, where it was scanned with an OBD2 scanner and DTC: C1391; was retrieved. The vehicle was not repaired. The manufacturer was notified of the failure and the contact was informed that the failure was related to an unidentified Toyota Campaign; however, the warranty had expired. The failure mileage was approximately 92,802.

The brake booster assist assembly failed, causing a leak of brake fluid, im told that over time this failure can lead to a break failure. I contacted Toyota. They informed me that there was an assistance program for fixing this defect. However it expired in 2024? If they know about a defect why did the program expire? This is a safety issue.

The contact owns a 2014 Toyota Prius V. The contact stated that while driving at an undisclosed speed, the brake pedal was depressed and traveled to the floorboard. The contact engaged the parking brake to stop the vehicle. The vehicle was able to be restarted. The dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was made aware of the failure. The approximate failure mileage was 100,000.

Failed Brake booster and pump assembly, confirmed by Toyota service. Warning lights turned on all at once: AEB, skid control and brake light. Estimated cost to repair is $3,000.

Break pump , break pump assembly, Break actuator. Vehicle has only 91k miles it. Breaks feel rough and slower to react. Too worried to use vehicle. Dealership said it’s a very well known issue and wanted $5800 to fix it.

The contact owns a 2014 Toyota Prius V. The contact stated that while driving at approximately 35 MPH, the brakes and ABS warning lights illuminated the instrument cluster. The contact had taken the vehicle to a local dealer, where it was diagnosed and determined that the brake booster and brake booster pump assemblies needed to be replaced. The contact was informed about the Customer Satisfaction Program: 20TE07 (Service Brakes, Hydraulic); however, the vehicle was no longer covered under the warranty extension. The vehicle was not repaired. The manufacturer was informed of the failure. The failure mileage was 133,838.

The brake booster assembly failed at odometer reading 92,463. Prior to diagnosis, several dashboard lights turned on, and the vehicle's braking was negatively affected. The failed brake booster assembly problem was diagnosed, confirmed and repaired by an ASE certified repair technician on 3/14/2024. Toyota refuses to reimburse me for this expensive repair ($2,375.97.) Toyota has operated in an unethical way by not issuing a true RECALL for this known defect. Its "Customer Support Program Bulletin" is full of unclear instructions and vague definitions of what is required for reimbursement. Toyota refuses to reimburse me for even a portion of this expensive repair. NTHSB should force Toyota to issue a recall and reimburse all affected customers who incurred this $2,000 - $3,000 repair.

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Toyota did implement an extended service warranty that ran through June of 2024 for a KNOWN issue with the ABS system. The problem was identified in a number of vehicle models, multiple recalls were made starting in 2019, and the Prius V (mine is a 2015) was excluded from that recall. After a road trip from Phoenix, AZ to Albequerque, NM, I started noticing a "farting" noise while braking. The extended service program had closed the month prior. I had the car inspected at my local AAA service department prior to leaving. The problem got worse, the braking is squishy and inconsistent, so I took it back to the shop. They've told me that my ABS system is not functioning and needs to be replaced. I called a dealership about the issue, and they said they can't honor the warranty unless Toyota does. They gave me the contact number for Toyota's Customer Care line, and I requested an appeal or exception which was denied. I have 85,000 miles on the car. It hasn't even rolled over yet. I don't drive very much and didn't drive really at all for almost 3 years between 2020 and 2023 since I was working online. There is nothing I could possibly have done to contribute to this issue, so it is CLEARLY a manufacturer error. Any issue with brakes poses a serious threat to safety and must be taken seriously. The repair cost is over $5,000, and MOST households cannot absorb that cost. If more vehicles are having similar issues, then I GUARANTEE you that there are more cars on the road right now with unstable brake systems that may fail at crucial moments. I have an appointment on Monday 2/10/24 with a the dealership service center. I have no idea if I'll be able to cover the cost of the repairs.

Brake booster system failed and needs replacement. Was told that there was a recall but it expired in 2024 and my car is not covered. Cal has 102000 miles on it.

Failed brake booster on 2014 Toyota Prius due to Customer Support Program Bulletin POL18-03 See attached documents sent to Toyota. They would not reimburse the ~ $3,000 repair to the brake booster which was in the Customer Support Program Bulletin POL18-03 Almost had an accident and the repair was done within the repair window.

Approximately 2 months ago my brake booster and accumulator pump failed looked up recalls on this issue my vehicle falls in the recalled model year was wondering if it is just overlooked because it has not had any problems with it in the past only 76000 miles on vehicle due to low mileage I believe it should not have failed it has a internal leak had vehicle scanned code C1391 was detected for abnormal leak of ACC press. Thank you For any assistance you can provide for me unable to afford repairs at this need vehicle for transportation to and from work again. Thank you

The car began to jerk, made knocking noises, miss fires on cylinder 1, 2 and 4, coolant leakages, oil leakages, compression issues and the check engine light keeps turning on and off. My safety has been put into play because, the car would jerk many of times as it would want to stop as I was driving. I would then have to pull over and call for assistance. Per the Toyota service advisor he recommended that I needed a new rebuilt engine kit. The extended warranty company stated that I was negligent with my car and denied my claim and refused to pay for the 10 grand motor and I had to tow my car to another shop. However, the car at this time is still experiencing the same malfunctions. The warning lamps are still showing at this present time and prior to the failure of problem. This car meets the "Lemon law guidelines, However, I have been informed otherwise that I don't meet the criteria for lemon law due it being expired sometime last year in Oct of 2024. As stated this is a lemon car.