general problems of the 2011 Toyota Prius - part 1

While driving, the brake, abs, traction light and other light lit up. The car lurched in an odd way. I can hear the oil pressure pump turn on every 5 seconds. Toyota shops told me the master cylinder and booster pump are failing and that the brakes will stop working while driving, causing an accident.

Abs, slip indicator and brake warning lights have appeared on the cars dashboard. Dtc fault code c1391 has appeared indicating a failure of the brake booster and brake booster pump assemblies per Toyota customer support bulletin (zjb) no. : pol18-03. Loss of regenerative braking, putting the safety off occupants at risk.

The master cylinder started failing while I was driving the car, the car only has 138k miles, the dashboard lit up like a christmas tree, all the warning lights were on, and when I went to step on the brake, I had to push it all the way to the floor for any braking to happen. I remember being scared for my life because I had almost no brakes which I could've got into a serious accident or been killed had it failed completely. I took the car to the dealer and they diagnosed it with code c139: abnormal leak at accumulator assembly, and recommended a new brake booster with master cylinder assembly and brake booster pump assembly with bracket. The car by age was not in Toyota's extended warranty on the parts but mileage-wise it still is, so I was footed with a $4-5k bill to replace both parts.

The abs, brake, and traction control are intermittently on and off recently. I thought that there was a visible leak in the brake fluid. But my mechanic said that there was no feasible leaks found upon inspection. The car has also been inspected in maryland without any issues. I came across many forums that said that this is a common issue in Prius. My safety was at risk if this is due to internal failure or defect of the product, especially because I drive with my [xxx] almost everyday to take her to daycare. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

VIN: [xxx] year/make/model: 2011 Toyota Prius mileage: 87,433 date: 11/4/2025 description sudden 80% brake loss. Loss of abs brake light + abs + traction control lights on dash (photo attached). Known failed brake actuator (c1391) — identical to 500+ complaints in pe19-004. Toyota corporate denied coverage (email attached). This is a safety recall issue — please reopen investigation. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Abs brake pump booster and actuator broke and got me almost into an accident. It's a known issue and it's a safety issue because car can still run but the brake is less sensitive. Please get Toyota to honor the repair.

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.

Abs warning system on dashboard is intermittent. I hear computer noises near the front driver tire. Then the warning light goes out or reappears on dashboard. Issue is the expensive diagnostic fee that may not unearth the cause, and if cause identified the diagnostic fee cannot be applied to the expensive repair. That’s a hard pill to swallow —and not affordable given economy, and I just had all four tires replaced along with a wheel alignment. Also, the yellow tire pressure light now blinks non-stop. (previously it blinked 3x then stayed on but stopped blinking. ) anyways, lots of covo about same issue in the 2011 Prius chat room I found after googling “2011 Toyota Prius abs warning system. ” wondering if software needs updating, or perhaps there’s a systemic mfg defect?.

I' m getting abs warning light. Dealer confirmed that I need to replace brake actuator and accumulator which costs me over $3k. Dealer refused to cover under warrant though it's a known issues with Toyota Prius vehicles.

My ability to break unexpectedly stopped working while I was on the highway during morning, rush-hour. I was going 55 mph on the highway at the time and luckily, I was on an uphill incline when they went out, thus allowing me to be able to ‘naturally’ slow down. But had I not been on an incline at that time of the brakes faulting, I would have 100% caused a wreck because I could not break at all. My emergency breaks weren’t even working, which is confusing because I thought that was the whole point of the emergency break, was for if your regular brakes become faulty… but none of my brakes worked. Which has created a new fear I didn’t know could happen while driving… also, all the lights that have to do with the breaking system were on (abs, traction control, break lights). And a consistent building up hissing noise under the hood.

Our trac abs and brake lights came on and braking became more difficult but not totally gone. I took it to my mechanic (not Toyota dealer) and he said the codes were going off for the abs hydraulic system and it would be $3000 to fix! this is unacceptable. I feel like my safety is affected but no one else has been hurt yet. I’m trying to be proactive. They first appeared last month. No manufacturer, insurance agent or cop has inspected it. It can be inspected by appt. Please help.

Abs actuator and pump failure.

Brake warning came on and wouldn’t go off. Followed by continuous beeping and now the brakes are no longer working properly. You have to force the brake all the way to the ground to even come to a rolling stop. The problem first occurred on 3/8/25. The brake actuator seems to be a reoccurring problem that Toyota addressed but is no longer fixing. It is dangerous to drive my vehicle and others have said their brakes have completely failed when this problem arose.

My brakes suddenly stopped responding correctly as I was pulling up to a busy road. My car went part way into traffic and I was nearly hit. After speaking to my mechanic and my local Toyota dealership, I was informed that there was a know issue with the brake booster and hydraulic accumulator on this vehicle and that Toyota had extended the warranty several times but that it no longer covered my vehicle. They never once acknowledged the safety issue and I was never notified of the risk. I believe the extended warranty was setup to avoid a recall and hide the risk. I firmly believe a recall should be done on these parts and owners should be notified of known safety risks this presents.

There were not any prior problem with my 2011 Toyota Prius' brake but it started making air pumping noises when I brake which makes me very nervous to drive my car. A local mechanic confirmed that the problem is the faulty brake booster assembly and pump. Toyota issued customer support program for this problem but covered only up to 10 years from the first date of use. Although my car has less than 120,000 mileage, I have to pay for this repair and it will cost me close to $2500 at a local repair shop! I want to go to Toyota dealership to fix but their cost is going to be even more! according to online research, many Prius owners have this same problem and have to pay out of their own pockets. This is unacceptable. Toyota should put a recall on this problem and cover the repair cost!!.

While driving on the interstate, the "brake", "tcs", and "abs" lamps lit up. The brake pedal was stiff and couldn't be depressed. The vehicle initially did not decelerate while attempting to push down on the brake pedal. While maneuvering off the interstate on to the exit lane, the pedal remained stiff however, the vehicle did begin to decelerate. Critically, the amount of time needed to bring the vehicle to a stop was significantly longer than normal. This brake failure could have resulted in a catastrophic, life threatening and/or deadly accident. The dtc associated with this brake booster and pump failure is c1391 which is referenced in TSB-0024-19. This is a known problem that exists in Priuses manufactured between 2010-2015 and addressed by Toyota with csp(s). The csp takes a reactive approach to this serious safety concern as owners who "have not experienced the condition described" were informed that "there is no action necessary at this time". The extended warranty of 10 years or 150,000 miles is not applicable to countless drivers who are experiencing this failure caused by "internal malfunctions" outside of this arbitrary time/mileage frame. A letter was sent to the NHTSA on 9/19/19 by the president of claremont and capistrano Toyota to petition for the initiation of a defect investigation regarding this issue. The letter notes that this brake defect is "causing crashes that are injuring people- and Toyota is mishandling it". The advisor assigned to this repair estimated that they see this issue 1-2 times a month and increasingly, drivers are not covered by the csp. Toyota is failing to take a proactive approach to this dangerous safety issue by telling owners to essentially wait and see if they experience this failure and then failing to take responsibility for said costly failure should it occur outside of their arbitrary time/mileage frame. This approach to safety is egregious, irresponsible, and unethical and it is putting countless lives at risk.

I have been doing some research, and the brake actuator and abs system failing is a common problem on these cars. Mine recently started acting up and they used to replace it for free. I got my Prius only 6 months ago and have not had any luck getting Toyota to replace it. This needs to be recalled it is a serious safety hazard if the brakes suddenly give out. They should be replacing this free on all cars having this issues and they are aware of the issue (Toyota). The brakes suddenly stopped working well and lights came on in this exact instant on the interstate. This first happened about a month ago. Tons of people are making complaints with the NHTSA for the same issue.

All brake lights on dashboard came on. Almost got into an accident because brakes were not responding. Brakes started responding but lights remained on. At time it will contibue to beep and brakes do not respond. I am seeing that this is a common issue happening to most Prius vehicles after a certain period. It is extremely expensive to repair. Since this is happening on quite a lot of Prius vehicles, I feel this should still be covered by Toyota. This appears to be a faulty brake pump and brake booster. This has not been inspected by a dealer but being that the car is a 2011, I'm afraid they will decline from what I have been reading.

In 11/2024, I started experiencing intermittent noises coming from the engine compartment of my 2011 Toyota Prius. The initial sound resembled the buzzing noise generated when first starting the vehicle. Then the noise started to persist for extended periods after the vehicle was turned off. It would oscillate between buzzing for approximately 10 seconds & remaining dormant for about 1 minute, repeating this cycle. The duration of these cycles could extend for up to 20 minutes. Concurrently, I experienced several instances where the brake pedal would abruptly become stiff & difficult to press. Notably, no warning lights were illuminated on the dashboard. Recognizing these symptoms as unusual, I conducted online research and discovered that the issue could potentially stem from a malfunction in the “brake booster pump and assembly. ” given the potential for a loss of braking power and the risk of personal/public safety, I scheduled a diagnostic inspection at Toyota of poway, poway, CA, on 12/18/2024. It confirmed the presence of a problem with the brake booster pump and associated components. In light of this diagnosis, I made the decision to refrain from driving the vehicle until the repairs were completed. The repair costs amounted to $3,475. 47. I found I had received a notification from Toyota’s customer support program, designated as “customer support program notification-zjb. ” this notification explicitly acknowledged this defect & provided a repair coverage policy that stipulated a coverage policy of which I’m no longer entitled to. Despite not meeting the eligibility criteria for the repair coverage program, I am deeply troubled by the fact that this recognized defect persists in vehicles currently on the road, such as mine, without any corresponding recall action and subsequent repair costs covered by Toyota. Fortunately, I was spared from any accidents as a direct consequence of this issue. Many similar complaints here support this dangerous issue!.

What component or system failed: 47070-47060 pump assy, brake booster w/accumulator yes 47050-47150 cylinder assembly, brake master with fluid yes put at risk: yes - abnormal braking abs failure-traction control loss has the problem been reproduced or confirmed by a dealer: yes has the vehicle or component been inspected by the manufacturer: not my specific parts were there any warning lamps: yes abs, traction control.

Have continuous display of abs , brake lights for some time. Diagnosed as problems of abs brake booster and pump. Toyota recognizes this issue but will not replace it.

The brake booster has failed. I was driving, and the abs, brake, and traction control lights suddenly came on. The brakes felt less powerful. I drove the car broadway Toyota in portland, oregon for maintenance. I was told that the system has failed, and while this is a known issue. It is not currently covered. I was also told that the car is not safe to drive. Toyota had a "customer support program" to cover this issue. However, the program expired on oct. 8th, 2021. Had I known, I would have brought it in prior to the expiration date. This seems like a recall issue. In Toyota's paperwork for the customer support program, it states that Toyota is aware of "certain internal malfunctions of the brake booster assembly"!.

Brake booster has failed. I'm told this is a known issue but no recall has been issued.

I was driving on a surface street at about 40 miles an hour and then the brakes suddenly don't work. You have to press on the brakes very hard to make them stop. All the safety warning lights were lit up on the dash. Took the car into the Toyota dealership and they said that there was a brake booster and pump customer support program but it's now expired so they won't fix it for free. The brake booster part is about $2000. I contacted Toyota customer service and asked them when they sent the notices out for this. They looked up our VIN number and said that the notice was sent to the previous owner, since we bought the vehicle used from a Toyota dealer. Spoke to a Toyota supervisor from customer service and told them we never were notified to fix the brake booster. The supervisor said they will not pay for the repair. I think this should be a safety recall and Toyota needs to repair these parts. It's very dangerous to drive the car when the brakes fail to stop.

To whom it may consern, I avoided a situation that could have been a very serious or deadly accident when my vehicle had unusual issue with the vehicle breaking system while driving on the freeway today [xxx]. The vehicle would not stop while pressing on the break pedal and I was able to quickly maneuver the vehicle on the shoulder of the freeway and was able to avoid a deadly crash. Looked on the dash and noticed that abs, break, and traction control lights all lit up. I was scared for my life and the safety of others around me. The vehicle was towed to my residence since it happened around 10:30pm California time. Quickly did some researched online for any recall on NHTSA. Gov website but unsuccessful with any recall regarding the breaking system. I also found out that it is a common problem that other owners have been/experienced with the same vehicle year, make and model. I would greatly appreciate for any information I can gather in order to assist me on how I can get Toyota to look into this issue for the safety of myself and others. It was a very scary scenario that could have been a tragic one that I found myself into. Looking for a prompt response to address this issue. Thank you! information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

Symptoms: the vehicle exhibits a constant and repetitive noise when the brake pedal is pressed. Additionally, multiple warning lights are illuminated on the dashboard, including the red brake light, yellow abs light, yellow traction control light, and tire pressure light. Suspected cause: the issue appears to be related to the brake actuator or accumulator. This may be associated with diagnostic trouble code (dtc) c1391, indicating an abnormal leak in the accumulator. This problem causes the brake booster pump to run continuously to maintain pressure, leading to the warning lights and noise. Safety concerns: the malfunctioning brake system components could compromise the vehicle's braking performance and overall safety. Purchase details: the vehicle was purchased recently from a dealership, and the issue was not present at the time of purchase.

On our 2011 Toyota Prius there is a complete loss of breaking. The abs, tcs, and brake lights all came on at one but went off after a few minutes. A few days later the entire system failed when the car was started and now there is no breaks at all on the car. A few months before we took the car to the dealership complaining about a noise when hitting the breaks and was told it was normal and to ignore it. It looks like Toyota knows about this issue and opened a customer care repair program but it expired in 2022 and was not advertised at all so the only way someone would know about it would be if they had an issue. Currently in order to fix the problem we are looking at around $3000 in parts and labor. Looking at other websites including this one the issues appears to be widespread.

For the past 2 years I've had issues with the abs, traction, and brake lights coming off and on on my dashboard of my 2011 Toyota Prius. Mechanics have replaced various things but have never been able to find the exact problem because the car doesn't either give any codes or it gives codes that don't really say what the exact problem is. I took it to a dealership again today, because not only are those 3 lights on but now the car is beeping continuously, and the dealership told me it was going to be over $5800 to fix the car, that's replacing the brake booster pump and the brake master cylinder, but the only code the car is showing is c1239, no other codes, c1239 is for the rear speed sensor lh. Every time I've had a mechanic/dealership look at the car, they can't find the exact issue and after replacing some parts, they tell me it could be the brake booster pump and the brake master cylinder, when I called Toyota corporate about the warranty stuff to cover those being replaced because of the faulty issues that have apparently been acknowledged by Toyota, Toyota refuses to have the warranty work done, telling me that my car no longer qualifies for that warranty work, although I've never received anything from them talking about this issue in the past. I'm told now the beeping is those two items have completely failed and the car is now unsafe to drive, but it's the only vehicle I have to get to work, etc. The lights will come and go, but stay on more steady now with the beeping sound. Toyota should help to cover this, since they know it's a known defect!.

Brake actuator failure on the freeway warning lights started beeping had trouble coming to a stop no brake pressure had to swerve to emergency lane. From my understanding there’s a brake actuator recall took it into Toyota my claim was denied .

As is the case with I am sure thousands of Toyota Prius owners, the brake actuator in my 2011 Prius has failed. The car has approximately 128,000 miles, but given that it is a 2011, the car is outside the Toyota 10 year/150,000 warranty extension. The deals wants $3,200 to repair. This part should last the life of the vehicle and I am asking NHTSA to help individuals such my myself and force Toyota to make the necessary repair free of charge due to the severe consequences to this part failing.

No incident, 3?? light started recently, traction control, abs, and brake light, 07/15/2024. Big o tire did oil change, inspection, claims brake are ok, warning ?? lights comes on and off intermittently, causes brakes when on to become soft pedal when stopping, I consider a defect of workmanship by Toyota on this 3011 model possibly others l. Thank you for your time.

The contact owns a 2011 Toyota Prius. The contact stated while driving at an undisclosed speed, the traction control, abs, and brake lights were illuminated. The contact stated that when the brake pedal was depressed, the contact heard air coming from the brake pedal. The vehicle was towed to an independent mechanic where it was diagnosed with a failed brake booster pump assembly. The contact was informed that the brake booster pump assembly needed to be replaced. The vehicle was not repaired. The manufacturer was made aware of the failure but provided no assistance. The contact was informed that there was an unknown customer satisfaction program with a similar failure description however, the contact was informed that the repair was not covered under the program. The contact was advised to contact the NHTSA hotline to report the failure. The failure mileage was approximately 74,000.

Driving yesterday on residential street, I gently applied my brakes to stop for a red light. The brakes did not stop the car; pumping the brakes did not help. Dashboard illuminated skidding car diagram, and brake light went on. I took my foot off the gas, rode somewhat on the shoulder, and slowly found a place to park the car. Had to have it towed. No prior warning that the brakes would fail. Dealership advised it was a leak in the brake booster pump or actuator. Later learned that there had been a class action lawsuit dealing with this issue. Also that Toyota had extended the warranty when this happened frequently. I never got a recall notice about this. My car is a 2011 Prius with 59,000 miles. The extended warranty only went to 10 years, and mine is 11 years old, but I haven't seen anyone else in the chat boxes who had such a low mileage as mine. Thankfully neither I nor anyone was injured. But this is definitely a major safety issue and a very expensive repair. Over $3,000. What recourse do I have?.

The contact owns a 2011 Toyota Prius. The contact stated that upon starting the vehicle, there was an abnormal beeping sound heard. The contact stated that several warning lights were illuminated. While reversing in the driveway, the brake pedal was depressed to the floorboard before the vehicle stopped. The contact's husband an independent mechanic informed her that the brake actuator needed to be replaced. The local dealer was not contacted. The vehicle was not diagnosed or repaired. The manufacturer was not contacted. The failure mileage was approximately 147,000.

On April 28, 2024 I was driving when my brakes became squishy and my abs warning light, red brakes warning light, and traction control light came on. I was very fortunate to be close to my destination and only traveling under 25mph. Roughly a week later it was driven approximately 150ft (on private property) and the brakes were very unresponsive. The car was never accelerated past 3mph for that move. The loss of braking was sudden and happened without any prior warnings. Had I been on a high traffic, high speed road, I believe it likely that this would have resulted in a catastrophic accident. The master cylinder actuator assembly and brake booster pump assembly failed. This was confirmed with obd and a snap-on solus ultra scanner. Both parts have been removed and are available for inspection upon request. They have not been inspected by anyone. I did contact Toyota about the braking issue and they did not express any interest in the issue or inspecting the failed parts. To make my Prius road safe and legal, I needed to replace the master cylinder actuator assembly and brake booster pump assembly. These parts were bought from Toyota, who has so far profited from my car's brake failure.