2012 Toyota Prius: brake failure

Filed Jan 25, 2026 · Brakes · MO

Vehicle: 2012 Toyota Prius Mileage: Approximately 217,000 miles While driving normally in traffic, the vehicle experienced a sudden and unexpected brake system failure. Multiple warning lights illuminated simultaneously, including the red BRAKE warning light, ABS warning light, traction control light, and warning symbol (!). Shortly after, the vehicle began emitting an audible warning/beeping, and there was a sudden loss of power brake assist. The brake pedal behavior changed abruptly: the pedal became very soft initially, then became suddenly hard halfway through travel, This failure occurred while approaching another vehicle in traffic, and I narrowly avoided rear-ending the vehicle in front of me. The unexpected loss of brake assist created an immediate and dangerous situation, as the vehicle did not decelerate as expected when the brake pedal was applied. Due to the seriousness of the brake failure and safety risk, the vehicle was removed from service and towed. This incident represents a critical safety defect, as sudden loss of braking assist while driving poses a significant risk to vehicle occupants and other road users. I am reporting this incident to document the hazard and request investigation into the reliability and safety of the brake system design. I am requesting you to please issue a recall and reimburse me , as these parts are very expensive , it affected my financial situation, Thanks

Filed Oct 31, 2025 · Brakes · MD

While driving 60 mph in highway, ABS, traction control and brake lights lit up and vehicle lost its effective braking power. There were no prior warnings prior to this failure. It was a sudden incident. Since it wasn't rush hour, I could safely reduce speed and bring the car to stop. Situation could have been much different if it was normal hours. After taking the car to dealership, it indicated DTC code 1391, Brake Assembly Failure. The car was fixed at dealership at cost of $3,000. When researched further, it appeared that there is broader pattern of failures. Numerous reports have been made by owners of 2010–2015 Toyota Prius, Prius PHV, 2012–2015 Prius V, 2012–2014 Camry Hybrid, and 2013–2015 Avalon Hybrid vehicles, all of which share the same brake booster pump assembly design manufactured by Advics Co., Ltd. Dealerships, including Capistrano Toyota and Claremont Toyota in California, have previously petitioned the federal safety agency regarding this very defect. Their 2019 letter to the agency documented that Toyota: * Knowingly excluded hundreds of thousands of hybrids from prior safety recalls (DOH 13V‑235 and KOL 19V‑544) despite identical failures. *Issued “post-failure” repair programs (Warranty Enhancements ZJB, ZKK, ZKC, ZLM, 20LE03, 23TE06 and 23TE07) only after owners experienced brake failure. * Identified the same DTC codes (C1252, C1253, C1256, C1391, U0293) in both recalled and unrecalled vehicles—codes that correspond to accumulator leaks, loss of brake pressure, and failure of brake assist and stability control systems. * Admitted through Technical Service Bulletin TSB-0130-19 that these defects caused loss of hydraulic pressure, increased stopping distance, and total loss of brake assist in affected hybrids. In short, the defect pattern across multiple hybrid models is identical to those already recognized by Toyota and the federal safety agency under prior recall campaigns, but for reasons unexplained, Toyota limited the recall population and left many consumers unprotected

Filed May 15, 2025 · Brakes · CA

I am reporting a sudden and dangerous failure of the brake booster in my 2012 Toyota Prius. While driving, I experienced a loss of braking power, accompanied by several warning lights including ABS, Brake, and the Traction Control system. The brake pedal became extremely stiff and unresponsive, significantly increasing the stopping distance. This failure nearly caused an accident, as I was unable to stop quickly enough when traffic slowed unexpectedly. This issue happened without warning and is a serious safety risk. I later discovered this is a common and widely reported defect in 2010–2015 Toyota Prius models. Toyota issued an extended warranty (Customer Support Program ZE3) to cover this known brake booster defect — but only for vehicles within 10 years or 150,000 miles. While my Prius has well under 150,000 miles, it is just over 10 years old, which disqualifies me from coverage, leaving me with a repair estimate over $4,000 for a well-documented manufacturer defect. This seems grossly unfair, especially for responsible owners with low-mileage, well-maintained vehicles. Toyota’s refusal to issue a formal recall and instead offering only limited support puts millions of Prius drivers at risk. A brake system failure of this kind should qualify as a safety defect and trigger a mandatory recall, not a quietly limited program with arbitrary expiration dates. I urge the federal safety agency to investigate this issue further and consider a recall of the defective brake booster system in these Prius models to protect public safety and ensure fair treatment for affected owners. Thank you.

Filed Apr 8, 2025 · Brakes · TX

Toyota installed known faulty brake booster and master cylinder systems in Prius C models manufactured 2012-2014. Knowing these systems would fail, but not wanting to pay for their mistake, they created a basically secret "extended warranty program" for owners to get their brake booster replaced ONLY IF for a specific 2 year time frame their brakes failed with a certain DTC code. Knowing that many prius owners would not actually receive the notification nor had driven their vehicle enough miles for the braking system to fail, they got away without having to correct their issue. The brakes literally just fail and stop working in the middle of the highway, causing extreme safety concerns and accidents with no responsibility from Toyota.

Filed Mar 27, 2025 · Brakes · OH

Subject: Safety Complaint – 2012 Toyota Prius Brake Booster Failure (C1391 Code) I am writing to formally report a serious safety defect in my 2012 Toyota Prius involving the brake system. Recently, my vehicle’s dashboard displayed the ABS, traction control, and brake warning lights, indicating a critical braking issue. Upon diagnostic testing at a Toyota dealership, the vehicle was found to have DTC Code C1391 – Brake Booster Leak/Accumulator Failure. I later discovered that Toyota acknowledged this defect and issued a Customer Support Program (CSP) to cover repairs. However, I was never notified, despite always servicing my vehicle at Toyota dealerships. When I contacted Toyota, they confirmed that my vehicle has been flagged in their system, yet I was never received anything in the mail about the potential brake failure. Toyota initially set the CSP expiration in 2023, later extending it to May 2025, but they have refused to repair my vehicle under this program. The estimated repair cost is $4,680.09 along with a diagnostic fee of 206.09, which is a significant financial burden for an issue stemming from a known manufacturing defect. Most importantly, this is a major safety hazard: My brakes now produce a loud hissing sound when pressed, indicating imminent failure. If the brake booster fails completely, it could result in a loss of braking power, endangering myself, passengers, and others on the road. Numerous Prius owners have reported similar failures, yet Toyota has not issued a formal recall. I urge the federal safety agency to investigate this defect further and push Toyota to issue a full recall instead of a limited support program that many owners were unaware of. Given the life-threatening nature of brake failure, Toyota should not be allowed to limit coverage or deny repairs for a problem they have long recognized. I respectfully request that the federal safety agency take action to ensure Toyota addresses this safety defect responsibly.

Filed Mar 16, 2025 · Brakes · KY

Brakes failed

Filed Feb 18, 2025 · Brakes · MI

I accidentally slid out into traffic as my brakes failed as I pulled up to stop at the edge of the parking lot. I was nearly hit driver's side on a pickup. Fortunately, it was able to swerve around me and there was no immediate following vehicle. I was able to pull out and back into a nearby parking lot to address the problem with my brakes. Upon speaking to my mechanic and local Toyota Dealership I was informed that the brake booster/accumulator had failed and that this was a known issue on my vehicle. Toyota extended a special warranty on these parts several times but did not notify owners of the safety risk. That warranty coverage has expired for my vehicle. I believe it is an inherent safety risk and they obscured it by covering the parts under this extended warranty. I believe they should be recalled and at the least owners should be warned of the risks. All communications were done over the phone or in person, I have no electronic records. I submitted an identical request on my 2011 Prius by accident, as I used it's VIN when I meant to use the VIN on my 2012 Prius. Regardless, I am now concerned for my safety in both vehicles.

Filed Jul 5, 2024 · Brakes · CA

In 2019, I took my Prius in for service. I reported that when I suddenly brake, the pedal feels spongy as if the brakes will not stop vehicle and lights on dash lit up. Toyota did diagnostic, no action taken by service department at Toyota dealership. I have service history documentation. On June 29, 2024 we had routine maintenance and the service department of the Toyota dealership recommended brake fluid serviced. On July 1, 2024, I was driving my child home from his summer camp and when I tried to stop the brake did not work. I started pumping the brakes several times until the car slowed and came to a stop. The lights on the dash lit up again. The brake failure put my son and I in danger. We had the car towed to the service department of the Toyota dealership. The service department sent the following information after their diagnostic. "The warning lights re-appeared after we drove it a few times. Now regarding the brake fluid service we performed, it is not related to those warning lights. Your accumulator is internally failing. The accumulator is a computer that distributes and controls the amount of pressure going into the brake system, and the computer was not untouched. Unfortunately it was bad timing and the computer started to internally fail. These vehicle's are known to have bad brake actuators, and Toyota created a type of recall for it to get replaced under no charge. Unfortunately they only cover up to 10 years and your warranty expired last year." My husband and I did not receive information regarding this recall. We did an online search to find out more about this recall and found several pages and posts of people describing the same situation.

Filed May 22, 2024 · Brakes · MO

Decreased braking performance. Sudden loss of ABS and Traction Control capabilities. (ABS light and Traction Control lights are now permanently illuminated on the dash). During the drive home, the brake response changed dramatically. More force is now required to operate the brakes. This failure occurred during a merge into traffic while on a merge ramp, going about 35 mph. It took what felt like a few seconds for both the vehicle and myself to adjust to the new braking requirements. During this time, it felt like a brief loss of braking ability. I continued to depress the brake pedal, and finally noticed a slowing of the vehicle. The pedal clearly requires much more effort and depress distance to begin slowing down the car. This decreased braking performance appears to be sustained until repairs are made to the vehicle.

Filed Mar 31, 2024 · Brakes · MS

Brake pressure actuator defect leading to major brake failure. No warning until it's too late.

Filed Dec 13, 2023 · Brakes · AR

Brake failure

Filed Aug 21, 2023 · Brakes · TN

My teenage daughter was driving and almost had an accident because the brakes failed. No warning lights came on until the brakes failed. I am learning now that it is a brake booster pump that Toyota knows about it as they had issued an extended warranty on the same thing that expired last year. Toyota confirmed that my Pruis was included in the customer service program but it has now expired.