2010 Toyota Prius

While driving my 2010 Toyota Prius, the brake warning lights suddenly illuminated and the brake pedal became soft and unresponsive. Stopping distance increased significantly, and the vehicle required much more pressure to slow down. This created an unsafe situation in traffic and could have easily resulted in a collision. A Toyota dealership diagnosed the issue as a failure of the brake booster and brake booster pump assembly (DTC C1391). This is the same failure Toyota previously acknowledged in Customer Support Program ZJB for 2010–2015 Prius models. My vehicle is experiencing the exact symptoms described in that program, but the support period has expired even though the mileage is well within normal expectations for a hybrid of this age. The sudden loss of braking assist is a serious safety hazard. There was no warning before the failure, and the vehicle became difficult to stop immediately. This appears to be part of a widespread pattern of brake booster failures on this generation of Prius, and the defect poses a risk of crash or injury. I am filing this complaint because this is a safety‑critical component that should not fail under normal use, and many other owners have reported the same issue. A review or investigation may be warranted given the frequency and severity of these failures.

In 2019 Toyota repaired my 2010 Prius(120,189 miles) braking system under the ZJB program. The brake cylinder assembly and brake booster pump assembly were replaced as they had a known defect that caused the braking system to fail. As of February 27, 2026 the replaced components are failing again. The auto has approximately 224,000 miles. So the replacement components failed in less miles and time then the original equipment failed which was determined to be faulty. Toyota has declined any assistance in the matter.

On November 25, 2025, at approximately 11:45 p.m., our 2010 Toyota Prius experienced a braking system malfunction during normal operation. The brake pedal required significantly increased effort and the vehicle exhibited reduced braking performance, indicating a loss of brake power assist. The vehicle required increased stopping distance, creating an immediate risk of a collision. At the time of the failure, multiple warning indicators illuminated simultaneously, including the brake system warning, ABS warning, check engine light, battery warning, steering warning, tire pressure warning, and vehicle stability control/slip indicator. There were no warning lamps or abnormal symptoms prior to the failure. The failure was determined to involve the brake booster pump assembly, a component responsible for maintaining hydraulic brake assist pressure. This component is known to experience internal accumulator housing degradation, which can allow nitrogen gas migration into the brake fluid and result in partial or complete loss of brake assist. The affected component remains available for inspection. Following the incident, an authorized Toyota dealership inspected the vehicle and reproduced and confirmed the condition. Service records indicate the brake booster pump assembly had previously been replaced under a Toyota safety recall. Despite this prior recall repair, the same component failed again after approximately 41,000 miles of service, demonstrating that the recall remedy was ineffective. As a result of this failure, the vehicle was rendered unsafe to operate. Despite dealer confirmation that the malfunction involved a previously recalled safety component, corrective repairs were declined, with warranty limitations cited rather than addressing the repeat safety-related failure.

It's a known quality defect covered under CSP ZKG. Toyota has received reports of paint peeling on certain vehicles with the original factory-applied Blizzard Pearl or Super White paint colors. These reports indicate that vehicles with these specific paint colors, applied during the vehicle manufacturing process, may experience paint peeling on exterior metal body panels. The Customer Support Program (CSP) provides coverage for involved vehicles with the original factory Blizzard Pearl or Super White paint. The covered condition may occur when sunlight over time degrades the adhesion between the factory-applied paint primer coat layer and the base metal electrodeposition layer causing the paint to peel from the metal body panel. If the condition is verified, the specific panel affected will be repainted. The problem is that I was not notified for my 2010 Prius II and found out today, November 19th, that the paint peeling issue was covered in a CSP. I contacted the Toyota of Richardson service department, Justin Houge, and he referred me to Toyota Headquarters in Plano, TX. I contacted Toyota Headquarters specialist, Amanda, and she informed me that the CSP expired on June 13, 2025 and to contact the dealership for remedy. Attached are photos of the blizzard pearl paint peeling on all four door panels and driver fender panel.

The contact owns 2010 Toyota Prius. The contact stated that while depressing the brake pedal, the ABS, brakes, and the vehicle stability control warning lights were illuminated. An Independent mechanic was contacted. The vehicle was taken to an independent mechanic where it was diagnosed and determined that the brake booster and accumulator needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure and informed the contact that the VIN was not included in the recall; however, the recall had expired. The failure mileage was 172,000.

One day after arriving home from work, all the sudden my ABS light, BRAKE light and traction control light turned on, my brake pedal being harder to push, and my car making weird humming noises every 5 seconds. Upon taking my 2010 Prius to my trusted repair shop, it was revealed that my break actuator was faulty. I drive on roads that need this part to WORK! Especially in the height of construction going on PA. One of the roads that I take has been milled up and upon driving on that road I nearly swerved onto the side walk 3 times! My breaking has been harsh and with one incident that nearly didn't break in time at all! Doing research and looking into the active investigations on this part, it turns out I am one of possible thousands who are dealing with this issue that has all been tied back to the break actuator being faulty which is very expensive to even repair for something that is obviously a poor design.

The brake and pre collision system suddenly fail without warning.

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.

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)

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.

Car keeps throwing a C1391 Abnormal Leak in Accumulator code. The ABS, traction control, and brake lights are all illuminated. Hissing sound from brake pedal. Spongy feel when braking and incredibly soft braking as well, very hazardous to driving and stopping. This is a known issue with the 2010-2015 Prius, and a quick internet search shows thousands of other Prius owners who also have this issue with their vehicles. It’s a safety hazard and can be potentially life threatening. Toyota is not doing anything to rectify this potentially fatal issue that impacts thousands of vehicles and vehicle owners and their families. Estimated cost of repair is upwards of $4,000 and simply not affordable to most consumers. Actions needs to be taken IMMEDIATELY by Toyota to recall these vehicles and fix them.

What component or system failed or malfunctioned, and is it available for inspection upon request? Brake Actuator failed requiring replacement of booster assembly with master cylinder and booster pump assembly How was your safety or the safety of others put at risk? This greatly impacted braking and stopping distance Has the problem been reproduced or confirmed by a dealer or independent service center? Yes, Toyota Dealership Has the vehicle or component been inspected by the manufacturer, police, insurance representatives or others? Yes, Toyota Dealership Were there any warning lamps, messages or other symptoms of the problem prior to the failure, and when did they first appear? No. These lights appeared after the failure - Brake, ABS, Traction Control

brake booster that was a recall that toyota said expired in 2020 when i bought the vehicle and the toyotal dealer didnt inform me of the recall to fix it said everything was fine when it was not, i had a dc inverter sensor brake booster issues and now it ills off my 12volt battery every time i put one in lasts about 1 mth, upset dealer never told me this wjhen took in tel me any recalls or probelms, they said none, they lied to me. it kills off my 12volg agm batteries in the last 7 mths been having braking booster issues problems grrr,,, noise all the time when the car is off too, its killing off my hybrid system and my temathetics module is having issues too because of all this and evey battery i put in the car, i want the ntc gov to have toytota recall fix these problems with my car and not expire the recall they had in 2020 cause now i cant fix my car cause of it, i was lied to by the lavista toyota dealer that it has no probblems in 2020 of august when i bought it no recalls and this recall could have been fixed if they would have been honest. unexpire the recall on my brake booster and my dc inverter and sensors probelms killing off my new batteries all the time. call me right away or email me about this, its a urgent matter life or death situation with this car, since the brakes are failing and i have to drive it every day and toyota mfg or dealer wont fix cause says expired recalls cant fix it.

The contact owns a 2010 Toyota Prius. The contact stated while driving at an undisclosed speed, the message "Hybrid Malfunction" was displayed, and the vehicle lost motive power. The contact was able to pull over to the shoulder of the roadway, where the vehicle was able to restart after detaching and reconnecting the rear battery. The vehicle returned to normal functionality, but the failure became a regular occurrence. No warning lights were illuminated. The vehicle was taken to the dealer, who was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was 120,000.

A few weeks ago, while waiting at a traffic light, the brake warning lights (ABS, Emergency brake, Traction control) lights on my 2013 Prius lit up and the brake pedal suddenly becomes much less responsive. I drove carefully back home, and researched online what the problem could be. To my surprise, this seems to be a known problem to Toyota, who had issued a campaign in the past to address this problem (ABS actuator, pump) and to replace the known faulty parts for free, but only for owners who were experiencing a failure at that time. Now the recall has expired, and owners like me who weren't having a problem at the time are stuck in a situation with cars that have a known, dangerous fault, while Toyota refuses to help with the problem anymore. The approximate cost for replace/repair is over $4000. All owners should have been included in the previous campaign, whether they were experiencing a failure or not, during that time period since Toyota knew that these parts are faulty.

i have have 2 problems, both was recalls, but this one they say expired in 2021 when i bought the car and toyota dealer didnt tell me had recall so i could fix it before it expired. there is a class action lawsuit in the brake booster, master cyclinder actuator abs pump fialing loosing brakes making grrr noises leaking all brake fluid out continously dangerous to drive can cause bad accident wreck since i drive down the hwy alot and this is the only car i have to drive, i also have dc inverter module /sensor that is killing off 3 batteries now that i installed in 3 months, and toyota dealers wont fix unless it shows error but its a recall so since problen should fix this recall but wont pay for it to fix it even though it a recall right now that is not expired. im upset 3 dealers wont do it unless then charge me to do it. when toyotal mfg take it to any dealer and they will fix free but no one will do it. toyota mfg needs to make these dealers fix these 2 recalls on this car that can kill me and my passengers and anyone on the road that i could hit by not haivng controll brakes or the hybrid system shuttong completely down and could even kill a pedestrian with these 2 recalls that dealers wont fix but mfg said they need to everyone with these cars i see are having these same problems. need make the toyota mfg and dealers fix these free of charge before more people get killed injuried or cause more accidents ,

Toyota issued a recall with a limited time for Prius brake booster/actuator failures. This issue is known to present brake failures and necessarily place drivers, passengers, and pedestrians at risk in the case of such brake failures. Toyota made no effort to proactively remedy this problem and further neglected customer safety by excluding Priuses with the same manufacturing issue from the recall, under its 10 year 150,000 mile requirement. Whether or not the Priuses have been driven 150,000 miles or 10 years the nature with which the malfunction presents represents a safety for any driver.

The contact owns a 2010 Toyota Prius. The contact stated while driving 45 MPH downhill on a mountain and depressing the accelerator pedal, the pedal travelled down to the floorboard, but the vehicle failed to accelerate as intended. The contact pulled over to the side of the road. The contact stated that upon turning off and restarting the vehicle several times, the vehicle responded as needed. The contact stated that the failure recurred after making a turn at 3-4 MPH downhill. The vehicle was not diagnosed or repaired. The dealer and the manufacturer were notified of the failure. The failure mileage was 194,000.

The contact owns a 2010 Toyota Prius. The contact received notification of NHTSA Campaign Number: 16V487000 (Air Bags); however, the part to do the recall repair was not yet available. The contact stated that the manufacturer had exceeded a reasonable amount of time for the recall repair. The dealer was made aware of the issue and confirmed that parts were not yet available. The manufacturer was made aware of the issue and confirmed that parts were not yet available. The contact had not experienced a failure. Parts distribution disconnect.

I purchased a used 2010 Prius on May 1, 2025. On May 5, the car would not turn on. Thought it was the battery. Replaced the battery on May 6. On May 8, the battery was dead again. I jumped the car and tried driving it to the Toyota dealership to have it looked at. On the way a loud beeping sound started and the ABS light came on. I pulled over and noticed the brakes felt strange. After having it towed to Ourisman Toyota, the told me the brake booster was broken causing the battery to drain. The cost for repair is a little over $4,000. This almost half of what I paid for the vehicle.