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KLUNK
KLUNK

2012 Toyota Prius

The Verdict

15 Total Klunk

The 2012 Toyota Prius has 685 owner complaints filed with NHTSA. The most reported issues are brakes (322 complaints) and body (128 complaints). With a Klunk Score of 15/100, it earns a "Total Klunk" rating. If you're shopping for a Toyota Prius, consider the 2021 model year which has 99% fewer complaints.

Safe Bet

The 2021 has 99% fewer complaints

View the 2021 Toyota Prius dashboard →

15

Klunk Score: Total Klunk

Among the most complained-about vehicle years on record. Strongly consider alternatives.

How is this calculated?

The Klunk Score ranks this vehicle year against all others in our database based on total owner complaints filed with NHTSA. 100 = fewest complaints (top tier), 0 = most complained-about. Scores above 60 are better than average; below 40 means more problems than most.

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Under the Hood

Each number is a complaint. Darker = bigger problem.

YearBodyBrakesElectricalEngineTransmission
2001941426325
200211826201712
200364167177
2004657233110933
200516627347310433
200613520310196318
200736231912077934
200824737770911250
2009901931534917
2010351190227822661
2011682581215813
20121283221248625
201371232474612
20145510144287
20153186231410
20161002127247
2017521212214
20181541061
2019109470
202064211
202130030
202275831
2023111502
2024152501
202562611

By Category

Brakes
322
Body
128
Electrical
124
Engine
86
Transmission
25

By Severity

1
299
2
306
3
6
4
73
5
1

Worst Problems

Complaints

Electrical 4

The contact owned a 2012 Toyota Prius. The contact stated that while making a left turn at 10 MPH, another vehicle crashed into the vehicle and t-boned the front passenger's side door of the vehicle. The air bags did not deploy. There was no warning light illuminated. After the impact, the front windshield slowly cracked. A Police report was filed. The contact and her husband were transported by ambulance to the hospital. The contact suffered a fractured sternum, five fractured ribs, a crushed left wrist, and two fractured bones in the left ankle. The contact's husband had a fractured neck and five fractured ribs. The vehicle was towed to a tow yard and was declared a total loss by the insurance company. The manufacturer was not made aware of the failure. The failure mileage was approximately 140,000.

24d ago
Brakes 2

Brake lights icons stay on mechanic at Toyota dealership state need new brak master cylinder and booster

1mo ago
Brakes 2

Brake warning lights on, buzzing sound every 10 seconds. Likely a known actuator and master cylinder issue

1mo ago
Engine 1

Unknown. There were a multitude of codes that appeared on the diagnostics causing problems with engine. The temperature, brake, tire sensor lights are all on. The cruise control is not working. White smoke emitting from tail pipe and engine. Main engine coolant leaking. Car overheating rapidly.

2mo ago
Brakes 2

My 2012 Toyota Prius is experiencing brake actuator pump failure, presenting diagnostic trouble codes C1253 (brake actuator pump motor stuck/locked) and C1256 (brake actuator pump motor overcurrent). These codes trigger ABS, brake, and VSC warning lights and disable ABS and stability control. Toyota previously acknowledged this exact defect under Customer Support Program ZJB, which covered 2010-2015 Prius vehicles for brake booster and brake booster pump assembly failures triggered by these specific codes. I am the original owner of this vehicle, purchased new in 2012. I never received notification of CSP ZJB despite being the registered owner at the time notifications were distributed in 2019-2021. My current mileage is under 150,000 miles, within the secondary coverage mileage limit established by the program. Toyota has declined to provide goodwill coverage citing program expiration. This is a known safety defect that reduces braking effectiveness and disables ABS — it should have been addressed through a mandatory recall rather than a voluntary program with an expiration date that left original owners without recourse due to failed notification.

2mo ago
Brakes 2

The power brake unit and actuator are failing.

2mo ago
Brakes 1

Almost had an accident due to the brake master, actuator and booster pump assemblies, failing. There were no warning lights alerting me to an issue. Just lost ability to break and car shut off completely while in motion.

3mo ago
Brakes 1

The brake booster and brake booster pump assembly (also referred to as the Accumulater or Accentuater) have failed in my vehicle the same as Toyota's known defect that was mentioned in their Customer Support Program 20TE07 (part numbers can be found within the filing of their CSP 20TE07). I am reporting that this issue appears to have affected more than their initial estimate of ~118,960 states impacted vehicles.l because Toyota is declaring my vehicle is outside of their CSP 20TE07 although their defect endangers my safety (and the safety of others) and attempts to put their defective vehicle brake parts as my financial burden. This issue should have been/should be a larger recall. Thank you.

4mo ago
Brakes 1

2012 Prius with 174,344 miles in great condition, with regularly scheduled oil changes. ABS/Break Actuator failure on freeway with no warning other than a beep a few seconds before the breaks disappeared completely. Break pads changed 4 months ago and new wheels installed as well. This is a known problem with Toyota under the TSB002419 where Break booster actuator was put on a customer service program to be fixed by the dealerships, but has since expired since 2022. The cars are still known to have their breaks go out due to this malfunction but it is now not covered by Toyota and cost $4K-$5K to fix which is more than the market value of the car today. This needs to be fixed and regulated.

4mo ago
Electrical 1

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.

5mo ago
Brakes 1

The contact owns a 2012 Toyota Prius. The contact stated while driving at an undisclosed speed, several unknown warning lights illuminated, with an abnormal sound coming from the vehicle. The vehicle was taken to the dealer where it was diagnosed with brake booster failure. The contact was informed that the brake booster pump needed to be replaced. The vehicle was not repaired. The contact stated that the failure was a known failure with the vehicle. The manufacturer was made aware of the failure. The contact was informed that an undisclosed Extended Warranty Program had expired. In addition, the contact was informed that the repair was not covered. The failure mileage was approximately 175,000.

6mo ago
Brakes 1

My Brake Booster/Actuator failed on me while on the freeway with out any warnings. It made it really hard to stop the car. I didn't find out what it was untill I took it into a repair shop and they told me it was the Brake Booster/Actuator.

6mo ago
Brakes 2

The vehicle is experiencing a suspected brake actuator / brake booster failure. Multiple warning lights appeared simultaneously, including ABS, Brake, Traction Control, and Master Warning lights. The vehicle produces a frequent buzzing noise from the brake system, especially at low speeds or when stopped. The noise occurs repeatedly when pressing the brake pedal, indicating the system is struggling to maintain hydraulic pressure. This condition raises serious safety concerns because it may reduce braking performance and increase stopping distance. Brake system failures present a significant risk to vehicle occupants and others on the road. After researching the issue, I learned this appears to be a common failure in Toyota Prius vehicles of similar model years, and Toyota previously issued extended warranty coverage for the brake booster/actuator assemblies. However, many vehicles now exceed the coverage limits despite the safety nature of the defect. I am submitting this complaint because a failing brake system is a critical safety hazard, and this issue appears widespread.

6mo ago
Brakes 2

Vehicle check engine code C1391 (Antilock Brake System - abnormal leak in accumulator) came up on 2/5/2026. Recommended repair is to replace the Brake Booster Pump and Assembly, Brake Booster - over $1000 in parts alone. This WAS covered by an Extended Warranty by Toyota (10 years / 150K miles). I only have 120K miles at this time but am past the 10 year mark. However, it seems that this part will fail in every Prius given time and encourage NHTSA to monitor these failures and hold Toyota accountable to address post the 10 year / 150K mile mark.

7mo ago
Brakes 2

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

7mo ago
Brakes 2

My 2012 Toyota Prius plug in hybrid had just passed state inspections and was even looked at by a dealership a year ago with no reported issues. I brought up a whirring issue at the dealership when breaking but the dealership said that’s normal for a hybrid. In a matter of minutes while driving, the traction light, brake light, and ABS light came on as well as a groaning, whirring sound when breaking. Over time, the breaks failed and I could not stop the car, almost causing a wreck because I could not stop without putting all my body weight on the break pedal. When taking it to the Toyota dealership for a whole diagnostic, they said it was a break actuator and break booster failure that is known to happen with Prius’s. They quoted me $3000 for a repair and then marked my breaks as yellow not red on their sheet implying I could still drive it despite the dangerous situation of driving without functioning breaks. When looking into it, this seems to be a known and common problem with Prius’s due to a faulty manufactured part. Codes were c1391, wc1256, and c1252. I believe this part should be recalled and Toyota should fix these faulty parts, especially considering they inspected my car and did not mention it as an issue despite it being a known issue. I got a second opinion from Mavis Tires and they concurred with the diagnosis but could not fix it.

8mo ago
Engine 1

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.

8mo ago
Body 2

The contact owns a 2012 Toyota Prius. The contact stated that while reversing, the driver's side rear wheel flipped over. The vehicle was towed to the dealer, where it was diagnosed with a corroded I-Beam assembly on the rear wheel. The contact was informed that the driver's side rear hub and the BRG assembly, rear suspension, and bolts needed to be replaced. The vehicle was repaired. The manufacturer was made aware of the failure. The failure mileage was approximately 196,347.

9mo ago
Electrical 1

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.

9mo ago
Brakes 2

While driving on a city road below the speed limit, braking was compromised leading to loss of traction and failure of the ABS system. During the incident, the brake, ABS, and engine warning lights all turned on and a collision was only avoided due to pumping of the brakes. Further investigation by a mechanic revealed a failure of the brake actuator system. Failure of this system has increased the stopping distance of the vehicle considerably and makes braking unreliable and unpredictable.

9mo ago

685 total

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