Service Brakes Problems of Toyota Prius - part 1

Brake actuator assembly failure on a vehicle with 99,818 miles. Whirring sound when braking followed by lighting of several brake alert lights on dash including pcs and abs and others. The whirring noise has occured for several weeks, but the light indicators happened on 6/28/26. Toyota has an acknowledged customer support program (20te07) for this exact failure on this exact and Toyota declined to cover the repair. This vehicle is 14 years old but has well under 150k miles and Toyota will not honor claim though they clearly are aware of the safety hazard.

See all problems of the 2012 Toyota Prius 🔎.

The vehicle experienced a failure in the braking system involving the brake booster/brake actuator assembly. The vehicle displayed diagnostic trouble code c1391, which is associated with a malfunction of the brake booster pump/accumulator system on this model. The failed component is available for inspection upon request. The failure created a safety concern because the braking system warning lights illuminated and the vehicle’s brake assist system may not function properly. A malfunction of the brake actuator/booster system could increase stopping distance, reduce braking performance, and create a potential risk of a crash, especially during emergency braking situations. The problem has been confirmed through diagnosis showing the c1391 trouble code. The issue has been identified as a brake system malfunction requiring repair of the brake booster/actuator assembly. The vehicle has been inspected/diagnosed by a service professional. The vehicle has not been inspected by police or insurance representatives. Toyota/dealer inspection information is available if requested. I contacted Toyota regarding the issue, but they declined assistance because the extended warranty coverage expired approximately 7 months prior to the failure. Before the failure, the vehicle operated normally. The first symptoms occurred when multiple warning lights appeared while driving, including the abs warning light, brake warning light, parking brake warning light (even though the parking brake was not engaged), and the traction control/slippery road warning light. These warning lights appeared suddenly, indicating a problem with the braking system.

See all problems of the 2015 Toyota Prius 🔎.

On June 20, 2026 while driving the Toyota Prius I experienced a sudden brake failure. Initially I thought I might have pressed the accelerator instead of the brake. But then pressing the brake I found the car did not stop and the abs brake, brake lights, and other lights lit up on the dash board. The car had only 61,150 on the odometer. I called on Toyota for their warranty coverage but they declined saying that the vehicle is no longer covered. This brake failure should have been under recall. Aaa auto service has pulled c1391 vehicle code - requiring removing and replacing brake booster pump assembly with master cylinder, etc.

See all problems of the 2013 Toyota Prius 🔎.

The abs actuator (brake booster) went out suddenly. It is 100% available for inspection. It is being towed to m&m auto repair in gaston SC. I was not sure if the car was going to stop when I was trying to figure out what was wrong. The car was acting like it wasn't going to stop until a few seconds later. People online have had a similar problem as me with Prius models around my year to 2015. And it was a problem confirmed by the dealership. The component has not been inspected. Only diagnostics were ran. The abs system light came on. But it would disappear for a long time then come back. So I thought it was a computer error for the longest until it proved to not be one. Because the brakes were working just fine like normal. Other than that, the light itself was playing peekaboo with me, making me believe that it was a computer error since the brakes were working just fine. Then on Monday, the car started beeping excessively and the brakes were not working suddenly after being fine over the weekend. . . . With no issues.

See all problems of the 2011 Toyota Prius 🔎.

The power brake unit and actuator are failing.

The contact owns a 2015 Toyota Prius. The contact stated that while driving at 45 mph, the brake warning lights illuminated. The brakes were inoperable and entered manual mode. The contact stated that the brake warning lights were red and yellow. The vehicle was taken to brake masters, where it was diagnosed with brake actuator failure. The local dealer was contacted but did not provide assistance. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 121,000.

My name is [xxx] currently active duty military stationed in san diego. Can you please check if my car VIN number [xxx] 2016 Toyota Prius c 103k miles still covered for brake booster malfunction code 1391. I have told they are extended warranty up to 10 yrs less 150k. Toyota dealer here seems not seeing any warranty coverage issues. Please help me look into this issues thank you. My contact number is [xxx] . Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

See all problems of the 2016 Toyota Prius 🔎.

Abs light came on 6 months ago as well as ((!)) light. As soon as those lights came on, the brakes had an increased stopping distance and it became harder to get the car to come to a complete stop. I have seen a few Prius owners in my area also having the same problem with their Prius. For my car, the abs light would come on, then turn off for 300 or so miles, then turn back on and stay on for about 300 miles. That has lasted for 6 months. I had almost gotten in an accident yesterday after getting brake lines fixed for 4th time, and we determine the actuator and accumulator are both bad. I have also seen a lot of Prius owners with the same code. Where I am at, my shop is quoting me $2300 for the fix in total. That is absurd.

See all problems of the 2010 Toyota Prius 🔎.

The abs system has failed. All brake related warning lights have appeared on the dash board and the abs no longer works. The car will brake for now, but the pedal is mushy. The issue was diagnosed by a dealer. The diagnosis from the dealer, based on diagnostic trouble codes they did not provide, is that brake fluid is leaking in the master cylinder and brake booster. The recommendation is to have both the master cylinder and booster replaced. This vehicle has 143,000 miles on it. No accidents have occurred as a result of the brakes yet but how long before the brakes ultimately fail is unknown.

There is a known problem with the brake booster and skid control that was a part of an customer support extended recall program. Our Prius has very low miles (less that 60,000) so the issue didn't trigger for us until recently. Unfortunately, we are out of the extended recall program of 10 years or 150,000. This doesn't seem fair since it is a known and documented issue from Toyota. Unless we fix the issue, we are at risk of losing braking control. All brake lights on the dash are on and it is currently in the shop.

Abs, brake, and traction control lights, all illuminated at once on the dashboard. Inspection found dtc c1391 indicating the accumulator is leaking or failing to hold pressure correctly. We are advised that the braking system performance will decline, eventually failing. An very expensive repair is required and Toyota apparently has a shortage of the parts required. We cannot drive the vehicle given the potential of braking failure and cannot get it repaired in a timely manner for lack of Toyota parts.

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

See all problems of the 2014 Toyota Prius 🔎.

Almost had an accident due to the brake master, actuator and booster pump assemblies, failing. There were no warning lights alerting me to an issue. Just lost ability to break and car shut off completely while in motion.

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.

I was driving my 2015 Prius for years and occasionally the brake, abs and traction light would come on this is a sign of a failing brake actuator and booster. Toyota and the ntsb ordered the following warranty enhancement https://static. Nhtsa. Gov/odi/tsbs/2020/mc-10181800-9999. Pdf my brake booster had been exhibiting signs of failing for years and I tried to get a Toyota dealership to replace and repair the parts under the warranty extension but I was told I had to wait until I had perminent dash lights and trouble codes. So I had to wait till the booster completely failed. By that time my car had exited the extended warranty perimeters and I am told it is no longer eligible. . . . Even though the components are faulty from the factory and exhibited signs of failure many years prior. I was told to wait until the compenent failed by multiple dealers. My car was in motion and the brake boosters failed, fortunatly it did not cause an accident but this is a serious safety issue. Toyota should have done a compleat recall of the brake actuator and booster pump, rather than have drivers use known faulty components until failure. Toyota corporate has refused to help in the repair of the vehicle despite it showing failure for years.

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.

There have been several reports of this matter and a ton of recalls due to the brake booster issues with all Prius makes and models from 2010 on. The recall was issued and ended before I purchased this vehicle and never fixed. The brake booster has recently began having trouble in my vehicle. I purchased it in February of 2024, the recalls all show they quit honoring them in 2023.

Brake pedal is going all the way to the floor the car barely stops. The abs and brake lights show up on the dashboard and won't go away; when I used a diagnostic scanner to find the problem, three malfunction codes involving the brake system showed up. This has been going on for five days now, and I am going to take it to the manufacturer for further inspection.

Second time !!!! during ownership of car that brakes fail. Same problem as before brake actuator/booster failures: multiple reports indicate issues with the abs actuator or brake booster pump, leading to warning lights ("braking power low", "abs system malfunction").

2011 Prius. 80k miles. Brake booster buzz coming on every 15 seconds now. Abs, traction and brake lights on. I’ve heard of many Prius owners with the same issue. I also have another Prius with the same issue at 120k miles. Brake booster accumulator codes popping up with 80k miles. It is a safety concern as the abs brakes don’t work. Almost every Prius is effected by this.

Code c1391 200k miles all the warning signs for brake booster issue came up. The cost is too high and I just missed the customer support program timelines because the code came up late. This needs to be a recall, based on how many people experience this issue consistently.

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.

Abs braking system suddenly not working. Abs, brake, and traction control lights all turned on.

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

Brake booster went out, car only has 78,000 miles.

Toyota Prius has a known problem with the brake actuator and booster. A notice was sent out in 2019 under the customer support program expansion with repairs up to 10 years or 150k miles. This is a safety issue and should be covered under a recall with no time or mileage limits since these problems are not showing up until after 10 years if the car has low mileage, as in our case. We just passed the 10 year mark, but only has 114k miles. No mention of repairs needed were made during regular maintenance visits with Toyota. Additionally, preventative repairs were not offered if the vehicle did not seem to be experiencing problems at that time. The brakes are spongy and unresponsive. The abs light , traction warning lights, and parking brake lights are staying on.

Actuator needs replacing, currently at 127k miles and displaying traction control, brake and abs warning lights. The repair will be a few thousand dollars, the cars market value is only around $6k. This is a known Toyota defect for this generation of Prius but Toyota hasn’t recalled these vehicles. I think Toyota should have to pay. The vehicle is out of warranty at 127k miles and it’s a 2013.

I own 2 2009 Toyota Prius. Both cars less than 175,000 miles and both have failed abs modules. The abs module in this vehicle is also the power brake booster. This failure can cause braking issues such as loss of braking or sudden brake application. Only known fix is replacement of the abs brake module which requires the Toyota techstream service computer.

See all problems of the 2009 Toyota Prius 🔎.

I was driving my car and suddenly the traction , hand brake and abs sign started showing up. I usually apply only 10% of force on brake pedal but after this I have to apply almost 60% of force to even slow down the car. Almost 90% force to stop the car it has threatened safety of my family. When diagnosed at autozone they told cannot determine error code. When reading in internet this seems to be common problem in Prius. Please help is fixing the issue as it is not at my fault. This seems to be manufacturing defect.

2012 Prius with 174,344 miles in great condition, with regularly scheduled oil changes. Abs/break actuator failure on freeway with no warning other than a beep a few seconds before the breaks disappeared completely. Break pads changed 4 months ago and new wheels installed as well. This is a known problem with Toyota under the tsb002419 where break booster actuator was put on a customer service program to be fixed by the dealerships, but has since expired since 2022. The cars are still known to have their breaks go out due to this malfunction but it is now not covered by Toyota and cost $4k-$5k to fix which is more than the market value of the car today. This needs to be fixed and regulated.

My 2010 Prius has experienced the following error codes: c12341 and c1391, prompting the dealer to recommend replacing the brake booster assembly and master cylinder for $3938. 89. This is a known issue with this vehicle and a customer support program (csp) was issued back in 2018, stating that if this vehicle displayed these codes, the repairs would be at no charge to the customer. Toyota extended this coverage to 10 years from date of first use or 150,000 miles (whichever came first). I never receied the notice. The details of the csp are below. (I found on the internet. ) "Toyota has received reports indicating various brake system related warning lamps illuminate due to internal malfunctions. The brake booster and brake booster pump are covered by Toyota’s new vehicle limited warranty for 3 years or 36,000 miles (whichever occurs first). However, because we at Toyota care about each customer’s ownership experience, Toyota is now offering a voluntary customer support program that applies to various brake system related warning lamps of covered vehicles as a result of internal malfunctions, regardless of whether the vehicle is out of warranty. The timing of any repair under this voluntary customer support program is subject to parts availability. The customer support program will be offered for all vehicles until November 30, 2019, regardless of mileage. In addition, the customer support program will be available for 10 years from the date of first use, or 150,000 miles whichever occurs first. " my vehicle has about 132,000 miles and just displayed theses codes. Since it is 16 years old, the csp has expired. It being a known issue, and one related to such a safety concern, I emplore you to make this a formal recall rather than a mere suggestion of repair. Back in 2018, my vehicle was not displaying these codes so was ineligible for the repair. Upon further research I am finding hundreds of Prius owners with the same issue. Clearly this is a defect in manufacturing.

I was involved in an auto accident on 4/20/2026 @ 6:23 pm. I was driving a 2006 Prius and the vehicle in front of me stopped to make a left turn. I applied my brakes, which grabbed slightly and then released. I then had to hit the brakes hard and they did the same thing again. I ended up rear-ending the vehicle in front of me and had to go to the hospital. I’ve been out of work since the accident, and I feel this was not my fault due to faulty braking system on this vehicle. My vehicle was declared a total loss, by the insurance company after doing my own research I have found many accidents with this type of vehicle that has had rear end accidents with injuries and some fatalities. It also shows not only this 2nd generation with this problem however the 3rd generation Prius as well. I have been out of work since the accident. I'm asking for a complete and thorough investigation into this and a satisfactory resolution to this so that it doesn't happen to anyone else. There were no warning indicators of any kind prior to the accident plus I had paid over 2000 dollars' worth of work and a set of 4 new tires put on this vehicle prior to this incident. Please advise and thank you.

See all problems of the 2006 Toyota Prius 🔎.

On 4/16/26, while driving my 2015 Toyota Prius (approximately 87,000 miles) on the freeway, I applied the brakes while transitioning from the [xxx] onto the [xxx] . As I veered right on the curved onramp, the brakes failed to engage properly, causing the vehicle to spin out of control and collide with the side railing. There were fortunately no nearby vehicles on the 2-lane onramp at the time. Under slightly different circumstances, this incident could easily have resulted in serious injury or death to myself and/or others. No airbags deployed. Although I was physically unharmed, I was extremely shaken by the incident. Immediately after the collision, the brake warning light, abs warning light, and another warning indicator illuminated on the dashboard. Prior to the incident, I had not experienced braking problems severe enough to suggest imminent failure. On 4/17/26, I brought the vehicle to Toyota of cerritos for diagnostic evaluation. I was informed that the brake booster was the issue and that the vehicle was unsafe to drive. The vehicle was towed to a collision repair center affiliated with my insurance company. After repairing the external collision damage, the collision center informed me that the brake booster malfunction that caused the incident could not be repaired there and would require dealership service. External repair alone: $3706, in addition to increased automobile insurance premiums expected over the next 3 years. I also contacted Toyota motor corporation regarding customer support program coverage related to brake booster issues and was informed that the program expired in 2025 and no assistance would be provided. I am submitting this report because this brake booster malfunction created a serious and unexpected safety hazard resulting in loss of vehicle control on a freeway interchange. Information redacted pursuant to the freedom of information act (foia), 5 u. S. C. 552(b)(6).

My 2013 Toyota Prius with only 99,000 miles is experiencing a brake system failure. The brake warning light, abs light, and traction control light all illuminate. The brake actuator pump runs every 10 seconds, indicating loss of hydraulic pressure. Safety concern: this issue affects braking performance and disables abs and traction control, creating a safety hazard, especially in emergency braking situations. This appears to be a known issue with Toyota Prius brake actuator assemblies. Toyota previously issued a warranty extension, but my vehicle is now outside the time window despite low mileage. This failure occurred prematurely and without warning. What happened: the warning lights temporarily went off after adding brake fluid but returned shortly after. The pump continues to cycle frequently, indicating system failure.

See attached document for complaint.