2012 Toyota Prius Electrical System Problems

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.

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.

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.

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.

I am writing to express a complaint regarding the issues I have experienced with the brake system of my Toyota Prius C, 2012 model. For the past several months, I have noticed that the brakes exhibit strange noises, soft pedal sensation, reduced braking efficiency, were driving and the ABS, traction, brake, and that other light turned on and the brakes became slow these issues have been observed on multiple occasions and pose a safety risk to myself, other drivers, and pedestrians. I have taken the vehicle for inspection, but the problems persist or have not been definitively resolved. I believe these faults may be related to defects in the braking system, and therefore I request a thorough inspection and necessary repairs at no cost, considering that the manufacturer could be responsible for manufacturing defects.

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.

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.

While my daughter was driving brake pedal faded and rear brakes locked up causing her to lose initial control of car . Steering felt tight . Many warning lights , check hybrid system , brake lights , steering warning lights , along with abs lights came on . Took car to Toyota dealer to diagnose it needs brake booster and master cylinder module . Service consultant said known issue with TSB but it had expired . Many , many complaints of this same incident of Toyota and Prius forums .

The hybrid system was shut down while driving. The symptoms are like the description in this recall (NHTSA Campaign Number: 18V684000). However, my VIN is not on the recall list.

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Our 2012 Toyota Prius experienced brake failure due to the Accuator and Accumulator. I contacted Toyota Corporate office, which advised it is a known problem and had a customer support program that expired last year. The Toyota rep advised me to not drive the vehicle because of the brake failure and opened a ticket advising it is a known issue. After researching online, it is a very common issue. https://www.aboutautomobile.com/Consumer-Complaint/2010/Toyota/Prius/Brake

In September 2022, my car, a 2012 Toyota Prius V with 79, 056 miles, began making noises in the engine area and the brakes became loose, meaning it took more pressure on the brake pedal to engage the brakes. In November 2022 the following warning lamps on the dashboard came on: Master Warning Light, Brake System Warning Light and Warning Buzzer, Brake System Warning Light, ABS Warning Light and SLIP Indicator. I took it to the Toyota Dealership near me: Lipton Toyota in Ft. Lauderdale, FL, and they diagnosed car with the trouble code of C1391-Abnormal Leak of Accumulator, Internal ABS Actuator Failure. To fix this problem, Lipton Toyota will charge $3124.29 for the repair. Toyota Motor Sales, U.S.A., Inc. issued a customer support program notification that would cover this repair if the malfunctions happened before coverage ended. Primary Coverage was applicable until December 31, 2021 with no year/mileage limitation. Secondary Coverage was applicable for 10 years from the vehicle's date of first use or 150,000 whichever occurs first. Date of first use on my Prius V was 03/01/2012 and my mileage is 79K. So as you can see, I am just out of the coverage window. My private mechanic and myself have appealed our case to Toyota that this problem should be a recall with no limits on coverage. (Toyota Motor Sales, U.S.A., Inc. - case reference # 230206000678) I believe that if I had driven my car more, (which was not done because of the Pandemic 2020-2021) this issue would have come up before the cut off date for repair coverage. I also believe that this problem with the Brake Booster and Brake Booster Pump Assemblies on certain 2012-2014 model year Prius V vehicles should be a recall.

I was driving on the expressway and experienced a sudden loss of power. The internal combustion engine suddenly stopped and did not deliver any power to the wheels. I immediately received a message on the system that said 'Check Hybrid System Stop Vehicle in a Safe Place'. The electric motor still continued to provide some power with the available battery charge. I was able to make it to the shoulder of the road but it was challenging to get to the shoulder with no power or warning and high speed traffic. My wife and I were in the vehicle. The vehicle had no engine or error codes until the failure on the expressway. The vehicle has the code P0A1A and P0A94. This is consistent with the error codes in the NHTSA 19V491000 recall and Toyota Safety Recalls E0E and F0R.

My breakes failed when driving. I almost got in accident. Code C1391. Brake Actuaror Failure. car has 200,000 miles. Toyota is denying to repair the car. It is well known problem with that but still not fixing.

Faulty brake and ECU assembly failure. A safety issue when driving. Was told by mechanic NOT to drive car as it could suddenly stop. Took car in 9/11/15 for software update for motor generator ECU and power management ECU as recall letter suggested. This is apparently common and needs to be corrected without cost to driver.

on the pasenger side front low beam light if the headlight does not sit correctly it melts the headlight housing and or the headlight is dimmer my damage wiring harness in past dealership blames owner feel like this is a part defect the heat from a bulb should not melt or damage housing assemblies damage was found during a new headlight install

Bought the car from a dealership in january 2022 with 158,000 miles and heard buzzing noise that I was told was normal with hybrid cars.no codes showing on car and passed dealer inspection.Driving down a highway and heading to a stop brakes are hard to mash and caused skidding. No brake lights or abs lights are on. Couple days later brake lights and traction lights come on and then went back off. Take to Tires Plus and I am told I have to schedule appointment with toyota dealer as they do not have the software to diagnose. Take to toyota dealership to see codes 1391c for brake system. After searching issue there was a recall/customer warranty extension for replacement of this part for 150,000 miles /march 19,2022 whichever comes first. This did not show up on a report for dealer to inspect before selling vehicle and causes a huge safety concern to people that did not own this car before 150,000 miles. If a less experienced driver would not have known to reduce brake pressure applied it could have slid and caused collision or if brakes would have been needed during an emergency situation. Car is now sitting at toyota dealership and advised not to drive as brake pressure was lowered while being diagnosed. After talking with toyota they cannot provide assistance due to car being slightly over the 150,000 mile mark. Also if the brake pedal is mashed for an extended period of time the dash lights for brake system and traction control go off and will not come back on until it is driven for awhile

.The contact owns a 2012 Toyota Prius. The contact stated while driving 35 MPH, the ABS, brake lights, and traction control warning lights illuminated. The vehicle was taken to a dealer but was not repaired. The manufacturer was notified of the failure and informed the contact that the vehicle had exceeded the 150,000 warranty. The failure mileage was 152,900.

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