Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2012 Toyota Prius owners, lightly cleaned up (personal details are redacted by NHTSA).
The engine caught fire while sitting in my garage. I had driven it for a few hours doing deliveries for a store and parked it in my garage around 2:30pm. About 1.5 hours later, my wife was coming home and opened the garage door and saw smoke above the hood of my car and then a few seconds later it burst into flames. I believe that it was smouldering for a while and the gust of wind when the big garage door opened gave it the extra push to ignite. The car was bought used and had a front end accident prior to my purchasing it so the electrical system could have melted and started the fire but the inspector that Toyota sent did not give me any copy of his report. It is a 2012 model. I bought the car in 2014, and had it for about 5 years until this happened and completed burned up the car and all the contents of my garage. …
The contact owns a 2012 Toyota Prius. The contact stated while attempting to use the horn, the horn failed to operate as needed. The contact also stated that the front passenger's air bag warning light illuminated and then turned off. The vehicle was taken to the dealer to be diagnosed. The contact was informed that the clock spring failed and needed to be replaced. The vehicle was also taken to an independent mechanic who confirmed the cause of the failure. The vehicle was not repaired. The manufacturer informed the contact that the vehicle was not included in the manufacturer communications regarding the clock spring assembly repair. The vehicle was not repaired. The approximate failure mileage was 90,000.
The contact owns a 2012 Toyota Prius. The contact stated that while driving at various speeds, the ABS warning light illuminated and the vehicle skidded while depressing the brake pedal. The contact stated that the hazard lights independently activated and caused the battery to drain, and the vehicle would stall. The vehicle was taken to a dealer where the contact was informed that there was a Customer Satisfaction Program for the failure, but the Customer Satisfaction Program had expired. The manufacturer was notified of the failure but offered no assistance. The vehicle was not repaired. The failure mileage was approximately 120,000.
Odometer Fraud. The contact's son recently purchased a 2012 Toyota Prius. The vehicle was a private sale. After the purchase, it was discovered that there was a mileage discrepancy based on the Carfax report. At the time of purchase, the vehicle displayed 137,000 miles. However, the Carfax report listed the mileage as 281,586 miles, and the current mileage on the vehicle was 151,103.
Odometer Fraud. The contact purchased a 2012 Toyota Prius. The contact stated that while attempting to register the vehicle, it was discovered that there was a mileage discrepancy. The vehicle was a dealer sale. At the time of purchase, the vehicle mileage was 187,000, and at the time of registration, it was discovered that the mileage was 227,000.
There has been a safety recall on my vehicle for the years 2004-2009 models of the Toyota Prius, but my model year is 2012 and I have the exact same issue. 1) My check engine light comes on and off and it appears to be the hybrid electric water pump issue related to the coolant. The cap pops off and spills out. 2) When the light comes on, I am assuming the car is starting to overheat and is putting myself and my 3 year old daughter at risk as this is the primary car we use to transport her. We have just stop taking her out at all due to this issue. When the car overheats, I pull over and it can be risky as sometimes, I am on the highway or local streets. I do not want this issue to cause problems for other other drivers as well while I am trying to pull over where ever I am. 3) The problem as I stated above has been acknowledge by you and Toyota but just for 2004-2009 models. …
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 (NHTSA 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. …
The accelerator wasn't pushing down after I turned a corner then the lights in attached photo appeared. The power inverter needs to be replaced and since my car had the J0V software update in 2/2019, and the recall update came out in 3/2019, it was not linked to my vin as it should've been. The update to J0V (attached) should have been posted w my vin, correct? They are fixing it under customer support but refuse to tow it or give me rental bc they are saying it isn't a recall issue, when the document below says it applies to all cars that needed J0V. I want to be sure all cars that had recall service before the March2019 update get this update linked to their vin.
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
I was driving on highway & the vehicle stopped accelerating as I was pressing the gas. I put my hazards on & got to the side of the road. Then the eps light came on & the dash stopped showing the mph. The ac stopped blowing cold air & the windows were working slow. I turned car off then back on a couple of times then more lights came on. No lights were on prior to this & I haven't had any problems w the vehicle before this. I just got this car & I feel like it has something to do with a recall but no one wants to take responsibility for the issue.
Related recalls
Electrical system › Software
Toyota is recalling certain model year 2010 through 2014 Prius vehicles. 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.
Remedy: Toyota will notify owners and dealers will update the software for both the motor/generator control electronic control unit (ECU) and the hybrid control ECU, free of charge.
NHTSA investigations
Pedestrian alert sounds
NHTSA received a petition on or about July 18, 2022, requesting that Federal Motor Vehicle Safety Standard (FMVSS) 141 be applied to all electric and hybrid vehicles operating in the United States. The petition can be reviewed at NHTSA.gov under ODI Number 11486072. FMVSS 141 establishes performance requirements for pedestrian alert sounds for motor vehicles.
Electrical complaints in other Prius years
Frequently asked questions
How common are electrical problems on the 2012 Toyota Prius?
NHTSA has 52 complaints about the electrical system of the 2012 Toyota Prius, 12% of the model year's 424 complaints. The component named most often is instrument panel › speedometer/odometer (2 mentions).
Is there a recall for 2012 Toyota Prius electrical problems?
Yes — NHTSA recall 14V-053 (software, Feb 12, 2014). Recall repairs are free at authorized dealers.
At what mileage do 2012 Toyota Prius electrical problems start?
Half of the complaints with a recorded mileage happened before about 40,000 miles, and 43% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 2 fires and 2 injuries to electrical system 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.