260 of the
652 complaints filed about the Toyota Prius V
are about the braking system —
100% of everything owners reported.
The worst model year for it is 2012.
2012 Toyota Prius v with 89,662 miles. Multiple brake warning lights illuminated, and the vehicle stored diagnostic trouble code C1391, “Abnormal Leak in Accumulator.” The brake booster/accumulator pump is also cycling about every 13 seconds, even when the brake pedal is not being applied. The vehicle and components are available for inspection. My safety concern is that this involves a critical braking-system component. When the warning lights are on, regenerative braking is disabled, and braking behavior changes. I am concerned that continued deterioration could reduce braking performance or result in loss of brake assist. The issue has not yet been formally diagnosed by a Toyota dealer. I scanned the vehicle with a diagnostic scan tool, which currently shows C1391. I also contacted my independent repair shop, which recommended that Toyota diagnose the vehicle because this code is associated with the brake booster/booster pump failure previously addressed by Toyota Customer Support Program 20TE07. The vehicle has not yet been inspected by Toyota, police, insurance, or another manufacturer representative. A Toyota corporate case has been opened and escalated. There were no known brake warning lights before this incident. The problem first became apparent when multiple brake warning lights illuminated. Afterward, I noticed the brake booster pump cycling unusually often. Toyota previously identified C1391 as a qualifying code under 20TE07 for certain 2012–2014 Prius v brake booster/booster pump failures. My vehicle is outside the time-based coverage period despite relatively low mileage. I am reporting this because I am concerned this safety-related failure may continue occurring in similarly aged vehicles.
NHTSA complaint #11763226 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11762896 — an unverified report by a vehicle owner.
The brake booster assembly failed, as many of these models had before. A bunch of codes went off as I was driving and the brakes did not function properly. Toyota had an extended warranty for this which they discontinued last year and they would extend no good will towards the $4,000 repair
NHTSA complaint #11761665 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11751973 — an unverified report by a vehicle owner.
My Prius had brake warning lights come on around December 2025. Turns out the brake accumulator had an internal leak. After doing some research, I discovered this was a known brake booster issue that Toyota has not issued a recall on. They do have an extended warranty program, but my vehicle did not qualify. The warning lights did not come on until after the 10 years or 150k miles cutoff for the warranty. Toyota's refusal to issue a recall and limits of their warranty program are clearly a move to avoid paying for repairs incurred as a result of defective manufacturing. Why should I be ineligible for reimbursement just because my vehicle is 13 years old rather than 10? Please make Toyota issue a recall or extend their Customer Support Program No. POL18-03.
NHTSA complaint #11751147 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11747171 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11745426 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11743546 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11737539 — an unverified report by a vehicle owner.
Suddenly Cars Brakes failed with vehicle almost lunged forward. I had to slam the brakes heavily for it to stop; Took the vehicle to Toyota Service and clearly its a QUALITY issue toyota acknowledged as a know problem with error code C1391. They even had customer support program 20TE07 acknowledging it as their issue; I almost got killed for this. The repair costs are abnormally high at 4900$'s putting me a financial burden also and currently unsafe car; Toyota - they literally KNOW THIS ISSUE and still put me at risk. They are refusing any kind of assistance to help too.
NHTSA complaint #11735136 — an unverified report by a vehicle owner.
The contact owns a 2013 Toyota Prius V. The contact stated that while pulling out of a parking space at approximately 15 MPH and depressing the brake pedal, the brake pedal felt spongy, but the vehicle responded as intended. The brake, the ABS, the traction control warning lights, and an unknown warning light were illuminated. The contact scanned the vehicle with a code reader and retrieved diagnostic trouble codes for the brake booster and brake accumulator systems failure. The contact related the failure to the Toyota Customer Satisfaction Program: 20TE07 (Certain 2012 - 2014 Model Year Prius V Coverage for Brake Booster and Brake Booster Pump Assemblies). The manufacturer was contacted and informed the contact that the vehicle was no longer covered because the 10-year limit was exceeded. The contact was referred to the dealer, who provided an estimate for the repair. The vehicle was not repaired. The failure mileage was approximately 120,000.
NHTSA complaint #11731817 — an unverified report by a vehicle owner.
When I'm in the car, the brake booster keeps recharging with out touching the brake pedal. Also, the car has problems when I apply the brakes while driving. They make a hissing and popping noise and the braking is spongy. I have had braking warning lights come on as well. It is similar to what others have been describing as the brake booster and pump actuator issue with these Prius V cars. This has been happening ongoing for about two years or so. I called the Toyota dealership and they would not check it out for free or remedy the issue that was part of their Customer Support Program (Policy 13V-235) for booster pump issues.
NHTSA complaint #11729269 — an unverified report by a vehicle owner.
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.
NHTSA complaint #11728818 — an unverified report by a vehicle owner.
The contact owns a 2012 Toyota Prius V. The contact stated that while driving at an undisclosed speed, the brake master cylinder was constantly cycling. No warning lights were illuminated. The vehicle was not taken to the dealer or an independent mechanic to be diagnosed or repaired. Most recently, while the vehicle was turned off, the brake master cylinder was cycling. The contact stated that while the keys were in his hands and standing several feet away from the vehicle, the brakes started cycling. The manufacturer was notified of the failure but offered no assistance. The approximate failure mileage was 140,000.
NHTSA complaint #11715101 — an unverified report by a vehicle owner.
Upon a hard (but not emergency) brake, my ABS and brake warning lights came on and my car began whirring once every few seconds. I immediately took the car to the Toyota dealership, who informed me that my master brake cylinder and booster had to be replaced, and that issues with the booster were something they had seen frequently in this generation of Priuses. I paid $5095 for repairs and inspection, but I had no other choice, as my brakes could have gone out at any moment whilst I was on the road and caused a very serious accident.
NHTSA complaint #11713700 — an unverified report by a vehicle owner.
The brake actuator and compressor is having repeated problems and causing the brakes to lock up completely while driving both in city and ON THE HIGHWAY. Abs/parking/normal brakes The lights on the dash all start flashing and beeping. ABS / emergency brake / exclamation warning / sliding / lights all on It also caused the speedometer to stop working and most of the lights of the computer part of my dash to not display information Problem code 1391 confirmed by mechanic This is a danger to me and other drivers and Toyota needs to take responsibility for these repairs because it can cost us our lives.
NHTSA complaint #11712245 — an unverified report by a vehicle owner.