Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2015 Toyota Prius owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2015 Toyota Prius. The contact stated that as he approached a stop light at 25 MPH, the brake pedal was depressed and traveled to the floorboard as he attempted to stop the vehicle. The brakes failed to operate without warning as he hit the vehicle in front of him. The air bags did not deploy upon impact. A police report was filed and both the contact and the other driver were able to drive away from the scene. No injuries were reported. Prior to this failure, the contact stated that the same failure occurred months prior while traveling at 20 MPH in the rain. The contact stated that the brakes failed to operate without warning as he depressed the brake pedal to the floorboard; he hit an unknown object on the road due to the failure. …
I bought this car brand new and have had it serviced regularly at a Greensboro Nc Toyota dealership. It has 127,000 miles on it. I starting hearing a grinding whirring noice a lot lately and determined it is a brake actuator/brake booster. Took it to the dealership and they confirmed it to be a brake booster going bad. Engages at least 4 times a minute. There is a customer support program for this repair from Toyota ZJB and covers the part up to 10 years or 150,000 miles. I am in the covered period but it has to break first before they will cover it even though they confirmed it is going bad. It has to "throw a code" before Toyota will pay. I reached out toToyota and they reached out to the dealership which is Greensboro Toyota in Greensboro, NC and their regional office won't fix it because it would come out of their pocket and Toyota won't fix until it breaks. …
The contact owns a 2015 Toyota Prius. The contact stated that while driving at an undisclosed speed, the ABS and the traction control warning lights illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with a leak in the brake fluid hose. The contact was unsure what repair was performed, but the vehicle was repaired. The contact stated that the failure reoccurred with an abnormal sound. The vehicle was taken back to the independent mechanic, and the contact was informed that the vehicle needed to be taken to the dealer for a complete diagnostic test. The vehicle was taken to the dealer, where it was diagnosed with brake booster failure. The contact was informed that the brake booster needed to be replaced. The vehicle was not repaired. …
On the morning of December 11th, 2024, the brake system warning light (ABS, yellow) illuminated on the dashboard along with the red BRAKE indicator and the yellow Vehicle Stability Control (VSC) system light. I consulted a mechanic who performed a computer diagnostic and informed me that the ABS module booster had failed. He said that will order the part to change it but meanwhile he advised me to drive more cautiously and maintain a greater distance from the vehicle ahead, allowing extra space for my car to stop due to the increased braking distance caused by the failed ABS module booster. Later that day, at approximately 5:30 PM, I was driving home in heavy traffic, with speeds not exceeding 40 miles per hour. The vehicle in front of me began to decelerate abruptly. When I applied firm pressure to the brake pedal to slow down my car, it lost all control. …
My mom was involved in an accident in her 2015 Toyota Prius on April 19, 2022, which she advised lurched forward at a stop and when applying the brakes to stop the vehicle, she said was unresponsive, causing her to clip a vehicle and sending her vehicle into a ditch totaling her car and injuring her passenger and her. I would like to have this investigated and hold Toyota responsible. This could have been much worse and lives could have been lost. She is now without means of transportation, and she is now possibly responsible for damages to property and bodily injury because of this. Through my research I have discovered multiple class action lawsuits brought against Toyota for the same exact models. I asked the police officer to run a scan on the computer, but he advised it was only for serious accidents. There was no indication of the problem or messages.
The contact owns a 2015 Toyota Prius. The contact stated that while driving at various speeds and depressing the brake pedal, the brake pedal went to the floorboard, and the vehicle hesitated while responding. The traction control, ABS, BRAKES, and cruise control warning lights were illuminated. The vehicle was taken to Gasket Masters Inc, where it was diagnosed and determined that the ABS assembly was leaking fluid into the braking system, and the ABS module had failed, causing the brake pump to fail. The vehicle was not repaired. Additionally, the malfunction warning light was illuminated. The vehicle was taken to the dealer, but was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 186,000.
The contact owns a 2015 Toyota Prius. The contact stated that while driving approximately 15-20 MPH, the ABS, brakes, and the traction control warning lights, and the malfunction indicator light were illuminated. Additionally, the vehicle hesitated to respond while depressing the brake pedal, causing the braking distance to be extended. The vehicle was taken to the dealer, where it was diagnosed with an abnormal leak in the accumulator and a leak in the brake booster pump. The dealer determined that the brake master cylinder and the brake booster pump needed to be replaced. The vehicle was not repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 94,100.
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.
The brake assist. Driving and suddenly no brakes. Happened 2x in this vehicle and had to get a tow each time, even after getting new brake pads the first time it happened at my mechanics. The dealer confirmed today that they would fix the problem at $2700. The lights for traction and abs went off with a warning sound. Pulled over both times and called aaa for tow.....each a separate incident.
While driving my 2015 Toyota Prius, the brake pedal became extremely stiff and hard to press. I was on the way to the dog park with my dog in the back seat when I had to press down very hard just to slow the car at a traffic light. It felt like I was stepping on a rock. The brakes barely engaged, and I had to use far more force than normal to get the car to stop in time. When I hit the brakes, they finally caught hard and suddenly and my dog went flying off the back seat and landed on the floor. She's fine physically, but now she's terrified of getting in the car at all. It was scary for both of us and felt totally unsafe. If I had been going just a little faster or if someone was walking across that intersection, it could've ended badly. I later found out this issue is tied to a known defect with the brake booster and accumulator system, specifically related to code C1391. …
NHTSA investigations
Brake Actuator Valve Wear
The Office of Defects Investigation (ODI) has received a petition dated September 19, 2023 from the owner of a 2012 Toyota Prius V requesting that ODI reevaluate its decision to deny DP19-004. In the letter, the petitioner reported experiencing an unexpected and complete loss of brake power while driving, accompanied by multiple dashboard warning lights.
Brake Actuator Valve Wear
On September 19, 2019, the Office of Defects Investigation (ODI) received a defect petition from Mr. Roger Hogan requesting that the Agency investigate and recall certain Toyota Prius, Prius PHV, Camry Hybrid and Avalon Hybrid vehicles for a brake actuator valve wear condition covered under Toyota Customer Support Programs ZJB and ZKK (subject CSP?s).
Brake complaints in other Prius years
Frequently asked questions
How common are brake problems on the 2015 Toyota Prius?
NHTSA has 93 complaints about the brakes of the 2015 Toyota Prius, 56% of the model year's 166 complaints.
Is there a recall for 2015 Toyota Prius brake problems?
No. NHTSA lists no brakes recall for the 2015 Toyota Prius, though it has 1 recall for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2015 Toyota Prius brake problems start?
Half of the complaints with a recorded mileage happened before about 41,000 miles, and 30% before 25,000 miles.
Is it dangerous?
Owners linked 11 crashes, 0 fires and 6 injuries to brakes problems on this model year. If you notice symptoms, have the car checked before driving further.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.