2012 Toyota Prius fuel system problems

Filed Dec 25, 2025 · Brakes, Electrical · NY

While driving, the vehicle experienced a sudden brake system malfunction without prior warning or gradual degradation. The vehicle was being operated under normal driving, road, and weather conditions. No recent brake service, repairs, or aftermarket modifications had been performed prior to the failure. Multiple warning lights illuminated on the dashboard, including the ABS warning light, brake warning light, and traction control warning light. Shortly after the warning lights appeared, the vehicle began emitting continuous warning beeps. Audible buzzing or pumping noises were also present from the brake system during the malfunction. During this event, brake performance was reduced and braking felt inconsistent. The brake pedal became hard at times and spongy at other times, requiring increased effort to slow the vehicle and resulting in unpredictable braking response. This created a safety concern while the vehicle was in motion. The driver was forced to alter driving behavior and exercise extreme caution due to reduced braking confidence and unpredictable pedal feel. The malfunction has occurred intermittently during normal driving. The condition temporarily resolves on its own and later reoccurs without corrective action. The suspected failed component is the brake actuator / ABS actuator assembly. A diagnostic scan retrieved fault codes C1252 (Brake Booster Pump Motor ON Time Abnormally Long), C1253 (Pump Motor Relay Malfunction), and C1256 (Accumulator Low Pressure), which are consistent with brake actuator malfunction. The failure occurred at approximately 154,000 miles. This vehicle model and generation have a documented history of premature brake actuator failures with similar safety-related symptoms reported by other owners. The condition places the driver and others at risk due to unpredictable braking behavior, reduced braking effectiveness, and repeated warning alarms while driving. Warning lamps and audible alerts continue intermittently.

Filed Aug 14, 2025 · Fuel system · 137,000 miles · IL

The contact owns a 2012 Toyota Prius. The contact stated that while driving at an undisclosed speed, the accelerator pedal was depressed; however, the vehicle failed to accelerate as intended. The contact stated that the check engine and the hybrid warning lights were illuminated, and the vehicle decelerated. The contact received notification of the federal safety agency Campaign Number: 18V684000 (Hybrid Propulsion System). The vehicle was taken to the dealer; however, the contact was informed that parts were not yet available for the recall repair. The contact was informed that the parts might be available within a week. The manufacturer was made aware of the failure but provided no assistance. The failure mileage was approximately 137,000.

Filed Aug 28, 2023 · Electrical, Fuel system · 120,000 miles · MS

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Filed Aug 7, 2022 · Fuel system · OR

I was driving my 2012 Prius on the highway at around 55 MPH. The Hybrid System Warning came on and the car lost all power and immediately began to coast. I was fortunate not to have been in or caused an accident but cars behind me had to swerve to avoid hitting me. I was able to coast to a middle median lane. After waiting 15-20 minutes, the car never regained power. We were finally able to push it off the road and into a parking lot. It never regained power.

Filed Feb 24, 2022 · Electrical, Fuel system · NY

I brought the car to the Toyota dealer already 3 times for the same problem,now happened again,they told me the first time,nothing wrong with the car,and I paid them,the second time nothing wrong they said,the third time they said it’s the 12 v battery has to be replace it,I did replace it,but still the same problem I have,the HYBRID SYSTEM problems ,the Toyota company should fix it ,because it’s something very unsafe it’s happening with my car,please help me to resolve this problem….. the car drive but stop anytime,I almost have a very bad accident with my daughter ON board

Filed Feb 2, 2022 · Electrical, Fuel system · CA

Hi, I have a 2012 Toyota Prius with around 120k miles that is completely inoperable. A local Toyota dealership is charging $3400 to replace both computers, but the more I research the more apparent it becomes that this is directly linked with past issues that were never fully resolved during previous recall attempts. The following article describes the exact situation my car is in (https://www.latimes.com/local/california/la-fi-prius-overheat-inverter-defect-20190414-story.html). When you combine that with the previous recalls back in 2014 & 2018, this quickly becomes a pattern. That pattern suggests that past software issues (1 & 2 below) were never fully resolved, and/or already caused premature damage to internal/computer components that then fail regardless. I spoke with the California Bureau of Automotive Repair who referred me to the federal safety agency. The agent I spoke with noted that because the Inverter wasn't actually replaced back in 2014 (Toyota only performed a software update), this part definitely could have been already damaged due to the software issues, which could then cause problems with the computers later on (which is what occurred). --- 1) the federal safety agency CAMPAIGN ID: 14V053000 - In the affected vehicles, the Intelligent Power Module (IPM) inside the inverter module (a component of the hybrid system) contains transistors that may become damaged from high operating temperatures. 2) the federal safety agency CAMPAIGN ID: 18V684000 - Excessive voltage in the Intelligent Power Module (IPM) within the inverter may cause the hybrid system to shut down, causing the vehicle to stall while being driven. --- General: - Computers both failed, not currently available for inspection as they are being replaced - If this computer failure happens again later (while on the road - as it has for other consumer), it's very dangerous as the car essentially shuts down on the spot - Dealer is dismissing this due to the car's age - No previous warning lights or messages

Filed Aug 2, 2019 · Fuel system · 69,500 miles · GA

Tl* the contact owns a 2012 toyota prius. While driving 20 MPH, the vehicle began to stall and a warning indicator signaled the contact to pull the vehicle over. The contact was able to coast the vehicle into a parking space. The vehicle was towed to marietta toyota (750 cobb pkwy s, marietta, ga 30060, (470) 938-8436) where it was diagnosed that the hybrid inverter needed replacement. The vehicle was repaired. The manufacturer was not notified of the failure. The failure mileage was unknown *bf .

Filed Apr 15, 2019 · Engine, Fuel system · 75,000 miles · IL

Soon after getting a recall software update for the hybrid system, the car displayed hybrid system check message and lost power. Car had to be towed. Created an extremely dangerous situation due to nature of problem while driving on the road and had to pull over right away.

Filed Dec 12, 2018 · Fuel system · CA

Tl* the contact owns a 2012 toyota prius. The contact received notification of the federal safety agency campaign number: 18v684000 (hybrid propulsion system). The dealer (south bay toyota, 18416 s western ave, gardena, ca 90248, 310‑323‑7800) was contacted and confirmed that the parts were not available for the recall remedy. The contact stated that the vehicle only accelerated to 9 MPH when the accelerator pedal was depressed. The manufacturer was not notified. The failure mileage was unknown. Vin tool confirms parts not available.

Filed Apr 2, 2018 · Fuel system · 79,000 miles · CA

My husband was driving the car preparing to turn to enter the freeway when the prius lost all driving power spontaneously at the same time prompted with a warning on the screen 'check hybrid system and park in a safe place'. The car lost all driving power including power steering but my husband was able to glide the vehicle across several lanes to a parked position before the freeway entrance. The car never resumed its ability to drive despite turning it off and an attempt to restart. The prius was towed to the house and towed again to the dealership the following day for an assessment and repair. As a toyota customer, we were informed the vehicle had experienced inverter/component failure. My vehicle had a recall years earlier to reflash software in the prius inverter, but this did not resolve/prevent the spontaneous inverter failure we experienced on wednesday, march 28, 2018. It has been brought to my attention that toyota corporation is aware of several customers reporting similar or near identical circumstances, but are not issuing a recall to prevent this from happening to a toyota driver on the road. Toyota is agreeing to replace parts at no cost to me, with no guarantee this will correct any inverter failure. I have requested the system be replaced based on toyota's corrective action on the newest prius models, but they have denied my request. If toyota is acknowledging cost for this vehicle failure, why is it not a recall? If toyota has made attempts to correct this vehicle failure in newer prius models by installing improved inverter systems, why am I being denied the safety of also having an improved and new inverter system installed in my prius after what we have experienced and reported to both the toyota dealership and toyota corporation? Please investigate before injury or fatality comes from this corporate neglect of an identified problem.