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 2005 Toyota Prius owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2005 Toyota Prius. The contact stated that while driving at an undisclosed speed, the left turn signal was activated, however, the left turn signal failed to function as intended. In addition, the contact stated that the four-way flashers failed to function as intended. The vehicle was taken to the dealer where it was diagnosed with a computer failure. The contact was informed that an unknown part needed to be replaced, or an unknown software update was needed. The vehicle was not repaired. The manufacturer was made aware of the failure but provided no assistance. The contact referenced an unknown recall with a similar failure description; however, the VIN was not under recall. The failure mileage was approximately 143,500.
The contact owns a 2005 Toyota Prius. The contact stated that while driving at an undisclosed speed, the brakes seized. In addition, the contact heard a squealing sound and the ABS warning light illuminated. The contact used the parking brake to stop the vehicle. The vehicle was not diagnosed or repaired by an independent mechanic or the dealer. The manufacturer was not made aware of the failure. The contact stated that the odometer was inoperable and failed to display the correct mileage. The contact stated that the odometer was stuck on 299,999.
The contact owns a 2005 Toyota Prius. The contact stated while starting the vehicle, the instrument panel failed to light up or show any electrical functions. The contact restarted the vehicle however, the failure persisted. The contact was concerned with not knowing the speed, mileage, fuel level, or engine performance while driving. The vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The failure mileage was approximately 129,000.
The contact owns a 2005 Toyota Prius. The contact stated when the vehicle was started, the instrument panel was inoperable. The vehicle was taken to the local dealer however, the mechanic was unable to determine the cause of the failure. The vehicle was not repaired. The manufacturer was not contacted or informed of the failure. The VIN was not available. The approximate failure mileage was 25,000.
When driving the vehicle multiple lights came on (ABS, VSC, & brake)! Brakes became hard to push at times and didn't feel normal. Took it to shop and had both ABS speed sensors replaced. Warning lights went away and brakes were normal again. After a day, the lights came back on and a constant alarm started sounding! The brake system failed and the vehicle was super hard to stop! Came very close to having a major accident on the interstate when this happened!!! It took pumping of the brakes and full force on the pedal to bring it to a stop!! Went back to the shop and was told that the ABS control module/actuator went bad and needs to be replaced. Was also told that this system is a known problem in Toyota Prius's for a long time!!!!!!!!!!!!!!
I had lost functionality for some buttons on the steering wheel that didn't directly impact safety. On replacing the clockspring mechanism inside the whweel I decided to inspect the old unit. Four of the lines in the flex cable are impacted by corrosion, three have already failed. The fourth line is one of the airbag's electrical lines. I'm filing an issue report because the airbag would be next impacted by this failure and I believe there's a fair chance the corroded line could fail during the vehicle's attempt to fire the airbag on the wheel.
The red triangle keeps coming on with engine repair light when ever I'm driving from Los Angeles. My mechanic said that there's a recall from 2004 for the water pump. Please advise. Thank you, [redacted]
On 2/27/09, my 2005 Toyota Prius' brakes completely failed. I was going downhill in an highly transited urban road (rte 123 in va, close to tysons corner). Thankfully I was only going about 40mph when the light changed to red. The 2 vehicles in front of me stopped. I pressed the brake pedal and my car accelerated initially, and then nothing. Brakes are meant to work. Always. I kept pumping the pedal hoping to engage the breaks, but they did not engage. What stopped me was the rear of a BMW x5. Thankfully I was the only injured party, and my injuries are mostly muscular. I could have died or I could have killed someone. In January, I had taking my car to the dealer because all the alert lights on the dash would sporadically go off. They kept the car for a week and claimed that the secondary battery needed to be replaced. I got my vehicle back and on 2/23/09 the issue restarted. …
I am currently experiencing troubles with my front passenger headlight. The problem first occurred about a year ago (jan. 2014) when I purchased the car used from a car dealer in tysons corner va. I took the car back within days of noticing the light kept going out and asked them to repair the issue since I had just purchased the car. They did so and said that it was most likely a faulty light and replaced it. It is a little over a year now and the same light is going out again. What is happening is that when I turn the car on and turn on all of the car lights to drive it at night, they turn on, but about 15-20 minutes down the road and unbeknownst to me, the right passenger light goes out. Because of the shape of the car, you cannot tell that it is out. The only reason I knew it was out again was because I got pulled over and given a ticket. …
Tl* the contact owns a 2005 Toyota Prius. While washing the vehicle, the contact noticed 2-3 drops of water entering the front passenger side window. The window was closed at the time of the failure. Additionally, when the vehicle was started, the contact noticed that the instrument panel failed and would not illuminate. The contact engaged the push-to-start button with the brakes applied to shut off the vehicle, but to no avail. The contact then shifted into park and attempted to exit the vehicle when the vehicle abnormally accelerated. The contact was knocked to the ground by the driver side door and sustained minor injuries. As a result. The dealer stated that the instrument panel computer needed to be replaced. The dealer failed to perform a diagnostic to determine the cause of the electrical failure or the acceleration failure. …
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 2005 Toyota Prius?
NHTSA has 178 complaints about the electrical system of the 2005 Toyota Prius, 17% of the model year's 1,051 complaints. The component named most often is instrument cluster/panel (7 mentions).
Is there a recall for 2005 Toyota Prius electrical problems?
No. NHTSA lists no electrical system recall for the 2005 Toyota Prius, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2005 Toyota Prius electrical problems start?
Half of the complaints with a recorded mileage happened before about 100,000 miles, and 22% before 25,000 miles.
Is it dangerous?
Owners linked 4 crashes, 3 fires and 8 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.