Problems · by component
2012 Toyota Prius V electrical system problems
73 owner complaints to NHTSA about the 2012 Toyota Prius V cite electrical system, 12% of all 615 complaints for this model year.
Complaints
73
12% of all complaints
Crashes
1
Reported by owners
Fires
3
Reported by owners
Injuries
2
Reported by owners
What owners say about the electrical system
Verbatim from NHTSA complaints, newest first
“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. No police or insurance inspection. Warning lamps appeared after 12V battery replacement three months ago.”
“Brake getting stuck on the floor would have to press on brake really hard just to get a response, this will happen out of the blue! Driving in highway or just driving off the driveway. I almost hit a car in front of me due to lack of brake, i had to swerve to the side! First appear 1 day after buying the car..This issue needs to be worked on right away.”
“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 am writing to bring attention to a critical safety issue affecting the 2012 Toyota Prius and other Toyota models equipped with the brake booster and actuator system. These components are failing at alarming rates, leaving vehicles with no functional brakes, ABS, or traction control. Additionally, this failure compromises the hybrid system due to the regenerative braking no longer working, potentially causing further damage to hybrid components and resulting in repairs costing several thousand dollars. Toyota issued Customer Support Program ZJB, which covered these issues for a limited period. This program was in effect from August 31, 2021, with no mileage or year restrictions, but offered secondary coverage for up to 10 years or 150,000 miles from the vehicle’s first use. Unfortunately, my vehicle, with approximately 130,000 miles and 12 years of age, was denied coverage when brought to a dealer after the program had ended. Despite the brake booster and actuator failing, the dealership did not advise me not to drive the vehicle, further emphasizing the gravity of this oversight. This is a significant safety hazard, as vehicles with these failures lack the…”
“Wednesday morning I went to start my car to go to work. I noticed the brake would not go down. It was difficult to press. I was unable to go to work safely. I brought my car to a mechanic where I was informed it was a faulty brake booster. When I researched online, I saw many many other Toyota owners went through the exact same issue. There is no recall but it’s a huge issue and a a safety problem.”
“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.”
Showing 6 of 73 reports. Read every report on NHTSA.gov.
Data from NHTSA Complaints API (owner reports, unverified) · synced Nov 9, 2026NHTSA vehicle page
Complaints are unverified owner reports to NHTSA and are not normalized for sales volume. One complaint can cite several components.