Which parts fail
Components named in complaints (accelerator pedal, throttle, sudden acceleration, cruise control).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2004 Toyota Prius owners, lightly cleaned up (personal details are redacted by NHTSA).
I need your help to get Toyota to fix 2 items: -ABS Accumulator: I understand Toyota at one time had a recall on the 'ABS Accumulator', that may have expired. At that time, I did not have any issue, nor was I aware of the recall. Now the 'ABS Accumulator' has gone out and is really hurting the braking. I had to get new brakes & they get locked because of the ABS malfunction. It is an expensive item - more than the cost of the car. I intend to keep the car for a long time, if Toyota can help me get the ABS Accumulator fixed? -MFD: The Multi-Functional Display (MFD) in the middle of the dashboard, has gone blank. It used to just partially blank out before, but now the whole screen is blank all the time, making it very hazardous to drive. Obviously, there is nothing I have done & it is a manufacturing defect, because it should last the life of the car. …
This occurred to me yesterday while traveling 60 MPH in 94 f heat on I-76 e just before the 676 / 76 split. I was traveling in the far left lane when the car suddenly lost power. Looking at the dash I noticed the shifter had moved itself into n (neutral), it would not move back into drive. I applied my hazard lights and began forced my way rightward across three lanes to the shoulder, speed rapidly decreasing and seemingly more sluggishly than a normal coast. I think the emergency brake was automatically being applied or I was fighting a braking system. One lane from the shoulder, a ups truck was headed for me from behind. Luckily, he was able to swerve into the shoulder and pass me there as he could not move left into other traffic. We only narrowly avoided a collision with me or the elevated barrier on the side of the road. I had only 10 MPH left and no ability to redirect my vehicle. …
Speedometer & other control information display went blank. Pulled over to side of road but unable to turn off engine. Contacted Toyota & was told problem is known & warranty extend to 9 years & unlimited miles. However, my vehicle is older than nine years, so I must pay estimate $1400 to fix & car will be unavailable for estimate 2 weeks. The vehicle is unsafe to drive, prior to this known problem occurring car was operating perfectly ( averaging 50 mpg per tank of gas, documented). This appears to be a safety problem that was known by the manufacturer, however they seems to be trying to hide this by making the statistical estimate that by extending the warranty the majority of these cars would be off the road and their lawyers & legal insurance would cost less than the few humans kills after this arbitrary 9 year risk period. I could have been killed as a result of this failure! …
Tl contact owns a 2004 Toyota Prius. While driving approximately 55 MPH the vehicle accelerated on its own. The vehicle crashed into a concrete divider on the highway. The contact stated that the air bags did not deploy. The contact was able to drive the vehicle after the crash. The driver and the passengers sustained injuries to their back and neck and were under going therapy for their injuries. There was no police report filed. The contact stated that the crash caused damage to the front bumper and the front passenger side door which would not open. The manufacturer stated that an inspector would inspect the vehicle. The inspector stated that there was a problem with the ABS brakes. The contact received the report from the manufacturer and they did not indicate that there was a safety failure and were unable to provide further assistance. The body damage was repaired. …
I am the owner of a 2004 Prius. After buying my car used 2 years ago I noticed that once in awhile the display, including fuel consumption, speedometer, odometer, and more, would not light up and that the car would not turn off easily several times I have been in situations where I have little gas an am unable to see my gas gauge or know how fat iam going on the highway. I understand that this was once covered by Toyota under the warranty extension but is not considered a safety concern. The warranty extension is expired. In what universe are a functioning fuel gauge and speedometer not considered a safety concern? I am also concerned that this will deteriorate further and cause an accident.
Tl* the contact owns a 2004 Toyota Prius. While driving in clear, normal road conditions at speeds of 50 MPH, the contact attempted to accelerate into the flow of traffic. She then applied the brake pedal, however the vehicle did not decrease in speed. The brakes would not engage and the rear of the vehicle spun out of control or fish tailed. The contact could not maintain control of the vehicle and crashed into a guard rail and a nearby tree. The vehicle was destroyed. The VIN was not available at the time of the complaint. The current and failure mileages were 100,000. Updated evoq. 05/27/10
My wife was coasting into a parking space with her foot on the brake. The engine apparently experienced a power surge causing the car to shoot forward violently going through a fence and over a two foot retaining wall, across a driveway and crashing into another car. Whether it was the gas engine or electric drive is not clear. Our daughter who was in the front passenger seat observed that my wife's foot was on the brake the whole time. Both my wife and daughter received neck injuries requiring treatment.
Tl contact owns a 2004 Toyota Prius. When he applied pressure on the brake pedal at 50 MPH in the dark, the vehicle would not stop. The anti-lock brake system activated, but the vehicle did not stop. Consequently the vehicle crashed into a tree. The vehicle was completely destroyed. He sustained injuries. The failure mileage was 62000. The vehicle identification number was unavailable.
Tl contact owns a 2004 Toyota Prius. The contact was driving approximately 40 MPH when the vehicle suddenly accelerated and crashed into a vehicle as she attempted to slow down. The air bags did not deploy and the contact was injured. The vehicle was destroyed. The failure mileage was approximately 74,000.
Dt:.how long and at what speed was the consumer driving before the vehicle lost power? Had driven about 10 minutes on commuting home was driving at least 50-60 MPH. B.was the consumer accelerating, decelerating, or driving at a steady- state when the vehicle lost power?driving at a steady state. C. Vehicle lost power, was the driver able to continue driving the vehicle? If so, how long and at what speed?not able to continue driving, could not restart vehicle. Did any warning lights appear before and/or after the incident occurred? An odd beep and then some symbols illuminated on control panel but can't remember what symbol, thinks it make have been a car with an x through it. Referred to owners manual. Called for help. . Came to a complete stop just seconds after the beep and warning lights. F was unable to restart vehicle. G. No restart whatsoever. H. Was the vehicle towed? …
Related recalls
Vehicle speed control › Accelerator pedal
Toyota is recalling certain model year 2004-2010 passenger vehicles. The accelerator pedal can get stuck in the wide open position due to its being trapped by an unsecured or incompatible driver's floor mat.
Remedy: Toyota filed an amended defect report on November 25, 2009, stating that dealers will modify the accelerator pedal and, on certain vehicles, alter the shape of the floor surface under the pedal.
Acceleration complaints in other Prius years
Frequently asked questions
How common are acceleration problems on the 2004 Toyota Prius?
NHTSA has 52 complaints about the speed control & acceleration of the 2004 Toyota Prius, 9% of the model year's 610 complaints. The component named most often is accelerator pedal (4 mentions).
Is there a recall for 2004 Toyota Prius acceleration problems?
Yes — NHTSA recall 09V-388 (accelerator pedal, Oct 5, 2009). Recall repairs are free at authorized dealers.
At what mileage do 2004 Toyota Prius acceleration problems start?
Half of the complaints with a recorded mileage happened before about 62,000 miles, and 29% before 25,000 miles.
Is it dangerous?
Owners linked 10 crashes, 0 fires and 9 injuries to speed control & acceleration 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.