Toyota Prius loss of power problems

Filed Nov 7, 2026 · Brakes · AR

ABS pump failure. This is a known issue for Toyota Prius owners. My Prius ABS pump is failing and I am losing power brakes.

Filed Oct 30, 2026 · Engine · IN

The front exhaust pipe assembly (heat exchanger) on my 2016 Toyota Prius leaked engine coolant internally into the exhaust system. Toyota has documented this condition in Technical Service Bulletin T-SB-0135-19 ("Low Coolant, MIL ON DTC P148F00, and/or Poor Heater Performance") for 2016-2019 Prius vehicles and released a redesigned replacement part (17410-37D40). In [October 2026], at about [97,000] miles, I found the engine coolant reservoir was emptying about every night (nearly a full reservoir) with no external leak. A shop pressure test found no leak. Coolant collected inside the tailpipe after the car sat overnight, and white steam came intermittently from the exhaust while driving. The car stored code P148F00. On XXX a Toyota dealer ([DEALER NAME], [XXX]) confirmed coolant leaking from the front exhaust pipe heat exchanger, per T-SB-0135-19, repair order #[RO NUMBER], and quoted $1,870 to replace the front exhaust pipe with the updated part. My concern is that a vehicle losing coolant this fast can run low without warning and overheat while driving, which can cause engine damage or loss of power, and the white steam from the exhaust may reduce visibility for drivers behind. I also worry that coolant entering the exhaust damages the catalytic converter. The car has been serviced regularly, and the leak was not caused by an accident or impact. Toyota covered this repair under its emissions warranty for 8 years/80,000 miles, but my car is past that and Toyota has declined goodwill coverage (Toyota case #XXX). I'm reporting this so the federal safety agency can see that the failure is happening in vehicles outside that warranty period and can evaluate whether it is a safety defect. Vehicle: 2016 Toyota Prius, VIN [XXX] Component: Engine and engine cooling / exhaust system Crash: No. Fire: No. Injuries: No. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 6, 2026 · Brakes · VA

While driving, my brake pedal would randomly lose power assist. The pedal would get hard and I couldn't press it down normally, and I had to push as hard as I could just to get the car to slow down. This happened more than once while driving and I almost crashed because I couldn't stop the car in time. A scan later showed codes C1252 (brake booster pump motor on-time abnormally long), C1253 (pump motor relay fault), and C1256 (accumulator pressure low), pointing to a failure in the brake booster pump/accumulator system. A repair shop confirmed this and said the brake booster assembly with master cylinder and the brake booster pump assembly with accumulator both needed to be replaced. I also contacted Toyota and was told my car was previously covered under a Warranty Enhancement Program for this exact part, which has since expired meaning this is a known issue with this component. The part is available for inspection if needed.

Filed Sep 14, 2026 · Brakes · VA · crash

I am filing this complaint to report an active, severe safety defect involving a sudden, un-warned loss of power braking assist due to a failing factory brake actuator/booster pump assembly. My vehicle is exhibiting the exact internal hydraulic seal failure, pressure drop, and audible hissing/sipping sound outlined in Toyota's prior technical service bulletins. Because the onboard ECU computer only triggers warning lights once a complete, catastrophic failure threshold is met, the system is currently masking the defect from the dashboard. However, the physical hardware is actively failing, requiring the high-pressure pump to run constantly to maintain braking pressure. This component failure dramatically increases stopping distances and presents an immediate, unreasonable risk of a crash. Toyota previously acknowledged this widespread manufacturing defect via Customer Support Program ZJB (20TA02). However, because Toyota chose to manage this critical safety hazard through a time-limited warranty extension rather than a mandatory safety recall, hundreds of thousands of vehicles are now left with a catastrophic braking hazard because the consumer coverage expired in 2022. I urge the federal safety agency to open a formal defect petition review to investigate these post-warranty failures and mandate a retroactive safety recall to protect the public.

Filed Jul 1, 2026 · Brakes · TX

I am filing a formal safety complaint regarding a catastrophic brake component failure on my 2013 Toyota Prius, occurring at less than 83,000 miles. The vehicle’s Brake Master Cylinder/Actuator Assembly has suffered an internal hydraulic pressure leak, causing the electric booster pump to run continuously to prevent a total loss of braking assist. This is a well-documented manufacturing defect that directly compromises passenger safety, drastically increases stopping distances, and threatens a complete loss of power assist while driving. Toyota explicitly acknowledged this inherent design flaw through its Customer Support Program (ZJB). However, they limited coverage to a strict 10-year expiration date from the first date of use. Because my vehicle has exceptionally low mileage and was driven gently, the component took longer to degrade, causing it to fail just outside Toyota's arbitrary time limit. Limiting safety coverage based on time rather than mileage penalizes owners of low-mileage vehicles for an engineered factory defect.

Filed May 28, 2026 · Brakes · CA

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.

Filed Mar 22, 2026 · Brakes · HI

Subject: Brake Booster/Pump Assembly Failure – Toyota Program ZJB / 23TE07 Description of Incident: I am reporting a failure of the brake booster and pump assembly on my 3rd Generation Prius (82,000 miles). While the vehicle is 11.3 years old, it is well under the 150,000-mile threshold of Toyota’s Customer Support Program ZJB. The brake pump began cycling every 13 seconds, indicating an internal pressure leak in the accumulator. This is a documented precursor to a total loss of power-assist braking. Despite the clear mechanical failure, no warning lamps or Diagnostic Trouble Codes (DTCs) were triggered, creating a safety hazard where the system could fail without prior electronic notification. Repair and Cost Details: Because the vehicle was 1.3 years past the arbitrary 10-year "Secondary Coverage" window, I was forced to pay $3,461.18 out-of-pocket for a known manufacturing defect. I would like to highlight a discrepancy in labor billing: while Toyota’s own technical bulletins (ZJB/23TE07) state the repair should take approximately 5.3 hours, the dealership charged 8.9 hours of labor for the same procedure. Safety Concern: By limiting coverage to 10 years, Toyota has left many low-mileage owners with a critical safety defect that degrades over time regardless of mileage. I request that the federal safety agency transition this from a "Customer Support Program" to a formal Safety Recall to ensure all affected vehicles are repaired and owners are reimbursed, regardless of the vehicle's age.

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 Nov 6, 2025 · Electrical · NC

The hybrid system fails to enter “Ready” mode with no SMR engagement audible from the junction box. Dashboard displays ABS, brake, engine, and master warning lights. OBD codes include U0142, U0155, and previously U0073 . Rear brake lights function normally when pedal is pressed. Dealer said to pay 250$ for diagnostic and diagnosed incorrect voltage from brake light switch and quoted $348.94 to replace, but refused to proceed with open safety recall J0V / 18V684 (the federal safety agency 18V684000) citing inability to achieve “Ready” mode. Recall covers inverter failure leading to loss of motive power. Dealer declined to jump 12V battery or use external power to perform required software update and inverter inspection. Vehicle remains inoperable and poses safety risk due to sudden power loss potential. Component (inverter G9200-47141) available for inspection. Problem confirmed by dealer diagnostics. No police or insurance inspection. Warning lamps appeared after 12V battery replacement three months ago.

Filed Jan 25, 2025 · Engine · NY

I own a 2010 Toyota Prius hybrid 4 door sedan. I am the second owner of the vehicle. I purchased it in 2018 from a used car dealer. The vehicle ran well up until 2022 where a “check hybrid warning would appear on the dashboard along with a yellow triangle and service engine light would come on and the vehicle accelerator would not respond and the car would have to glide to the side of the parkway. This problem would happen when the car speed is between 60-70mph. It is very dangerous to lose power on the highway because many times there is no where to pull over. In 2024 I changed the water pump because the fault code on the cars built in diagnostic code read error “P216B” which is the cars electrical water pump signal. I researched it on google and a lot of 2010 Prius owners are complaining of the same thing. Also the changed water pump from April 2024 died again in January 2025. It is very scary that the cars accelerator pedal goes unresponsive and all the fault lights come on. My vehicle has 155,000 miles runs great and my family loves the 40mpg it gets. However, this stalling problem is being ignored by Toyota and could lead to a fatal car accident if not recalled by the manufacturer. To conclude, I would like for your office to possibly conduct an investigation with the 2010 toyota Prius hybrid for this ongoing problem that the company is ignoring. This is a serious issue and can possibly lead to a fatal accident. THANK YOU FOR HEARING MY COMPLAINT AGAINST TOYOTA.