2011 Toyota Prius electrical system problems

“I was driving my car at over 70 mph on a highway, no check engine, no issues, just had oil changed when check hybrid system alert came on with check engine light. I started to change lanes to get to shoulder when my car just died, completely. It died in the middle of the highway merging with another major road, so I was stuck between 2 lanes of 70mph traffic on either side. The time to react to the sudden warning to my car dying was less than 2 minutes. I quickly called 911 to ask for help and was told someone had already reported my breakdown as well because my car had died in a horribly dangerous area. I was very lucky that a state trooper came quickly and blocked off my car until it could be towed for repair. I was told that I need a new Hybrid Battery. The fact that I had no signs of failure before complete shut down makes for a very dangerous driving situation and makes me second guess ever buying a Prius again.”

“Odometer Fraud. The contact purchased a 2011 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 mileage was 145,000 and at the time of registration, it was discovered that the mileage was 227,000. The contact stated that while driving at 60 MPH, the check engine warning light illuminated. The contact took the vehicle to Auto Zone and was informed that the catalytic converter had failed and needed to be replaced. The contact was informed that it was not a new failure and that there was a possibility that the dealer may have removed the check engine light prior to the sale.”

“Around 14 months ago (march 2024) I purcheded a replacment battery pack for our 2011 Toyota Prius form NexPower Energy (also going by, project lithium, sodiumhybrid) based out of CA. The battery pack is a lithum pack that replaces the orginal nickel metal hydride pack. In the beginning of June 2025, the car through an battery error and went into limp mode wile my wife was driving, when i go home and plugged in my scanner to check the battery out i noticed that the cells were out of balance and some were becoming very over charged. My fear is that if the cells were continued to be overcharged an thermal runaway event might occure due to BMS not being included with the overall pack.”

“The contact owns a 2011 Toyota Prius. The contact stated that while operating the vehicle, the check engine warning light remained illuminated, the vehicle had unexpectedly shut off. Additionally, the transmission failed to shift into the intended gear. The vehicle was towed to the local dealer who replaced the catalytic converter, but the failure persisted. The vehicle was towed back to the dealer who diagnosed that the inverter was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure, but no assistance was offered. The contact was informed that the VIN was not included in the NHTSA Campaign Number: 14V053000 (HYBRID PROPULSION SYSTEM, ELECTRICAL SYSTEM). The contact stated that the vehicle had experienced the failure listed in the recall. The failure mileage was 117,000.”

“In 11/2024, I started experiencing intermittent noises coming from the engine compartment of my 2011 Toyota Prius. The initial sound resembled the buzzing noise generated when first starting the vehicle. Then the noise started to persist for extended periods after the vehicle was turned off. It would oscillate between buzzing for approximately 10 seconds & remaining dormant for about 1 minute, repeating this cycle. The duration of these cycles could extend for up to 20 minutes. Concurrently, I experienced several instances where the brake pedal would abruptly become stiff & difficult to press. Notably, no warning lights were illuminated on the dashboard. Recognizing these symptoms as unusual, I conducted online research and discovered that the issue could potentially stem from a malfunction in the “brake booster pump and assembly.” Given the potential for a loss of braking power and the risk of personal/public safety, I scheduled a diagnostic inspection at Toyota of Poway, Poway, CA, on 12/18/2024. It confirmed the presence of a problem with the brake booster pump and associated components. In light of this diagnosis, I made the decision to refrain from driving…”

“The low-beam headlamps on thousands of 2011 Toyota Priuses were burning out very prematurely (a matter of weeks, not months). Toyota Corporate said they created a customer support program to replace the headlight wiring harness free of charge, but this program ended in 2019. I believe that Toyota should be compelled to issue a recall to replace the wiring harnesses on all 2011 Toyota Priuses, because working headlights are a critical component of a safely traveling vehicle. The cost of replacing the wiring harness is more than $700, a real dent in a working family's budget. For now, we are replacing the burned-out bulbs. However, we believe a recall initiated by NHTSA is warranted in this case.”