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really awful
Crashes / Fires:
10 / 0
Injuries / Deaths:
9 / 0
Average Mileage:
44,925 miles

About These NHTSA Complaints:

This data is from the NHTSA — the US gov't agency tasked with vehicle safety. Complaints are spread across multiple & redundant categories, & are not organized by problem.

So how do you find out what problems are occurring? For this NHTSA complaint data, the only way is to read through the comments below. Any duplicates or errors? It's not us.

2004 Toyota Prius engine problems

engine problem

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2004 Toyota Prius Owner Comments (Page 1 of 3)

problem #45

Jul 092015


  • 200,600 miles


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! fortunately I was not, however I am left with a vehicle that is undriveable (with no warning!) and can only be repaired by Toyota at a cost I am not able to afford!

- South Pasadena, CA, USA

problem #44

Feb 012012


  • miles
2004 Toyota Prius. Consumer states unintended acceleration the consumer stated the sudden acceleration happened three times, over a six year span. He managed to put the vehicle in neutral, coast to the side of the road, and turned the vehicle off. Once the vehicle was restarted, all worked fine. The consumer stated a few weeks ago his vehicle was about to reach 300,000 miles, as he reached for his camera, he realized the odometer never went past 299,999 miles. However, within five miles, the vehicle suddenly lost power brakes, the air condition stopped working, the hybrid drive shut off and the fan for the hybrid battery came on, as well as yellow and red lights appeared on the dash. Also, two warning graphics appeared on the navigation screen, one indicating trouble. The consumer pulled over, and shut the engine off. He then restarted the vehicle and everything went back to normal. It appeared that by shutting off the engine and restarting it, caused the main computer reboot. The consumer stated it continued several more times, until he arrived home. The dealer informed the consumer the vehicle was a large computer, and when one component stops working, such as the odometer, other components cease too. The dealer explained an odometer limit was placed on the vehicle by the factory.

- Orange, CA, USA

problem #43

Mar 012011

Prius 4-cyl

  • 160,000 miles
When ambient temperature is cold, sometimes dashboard lights and speedometer do not come on when the car is started. Car runs but with no instrument panel. Sometimes when the car is in this state the car cannot be turned off by pressing the start button. Car can only be turned off by pressing and holding the start button down for several seconds, and even this does not always work. This problem has been getting worse over time. Toyota dealership refuses to investigate the problem, but it is documented in their warranty repair T-sb-0172-09 combination meter intermittent display bulletin. Instead, the dealership tries to sell us a new car!

- Pine Grove, CA, USA

problem #42

Oct 052011

Prius 4-cyl

  • 86,360 miles


While driving slowly in traffic, after a particularly rough transmission shift, the large red exclamation mark warning inside a triangle lit up on the dashboard, along with the yellow "check engine" and "vsc" (vehicle stability control) warnings. The car was pulled over to a safe location and stopped. The engine was turned off and on a few times and the warnings continued. On the fourth or fifth turn-on, the problem cleared itself and has not recurred. This is the second electronic glitch that has occurred on this vehicle while driving. The first was reported as ODI id number 10407518. Both times, the problems, which had different symptoms, corrected themselves after turning the engine off and on a few times. Since the dealer was unable to duplicate the problem in the first case, the dealer has not yet been informed in this case. It has been exceedingly fortunate that both of these electronic glitches, neither of which were related to floormats by the way, were not of the sudden-unwanted-acceleration variety. The randomness of both the timing and the symptoms of these electronic glitches suggest that sudden unwanted acceleration could easily have been the result.

- Roanoke, VA, USA

problem #41

Oct 052010


  • 120,000 miles
The 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. The contact stated that she did not feel safe driving the vehicle after the failure. The approximate failure mileage was 120,000.

- Kennewick, WA, USA

problem #40

Apr 192010

Prius 4-cyl

  • miles
2004 Toyota Prius. Consumer asserts that vehicle accident was caused by a computer malfunction the consumer stated prior to the accident, on one occasion, the vehicle bolted and jerked slightly as she stopped the vehicle. When she attempted to take off, the vehicle responded sluggishly and then accelerated quickly. The day of the accident, as the consumer approached the stop sign, the vehicle started bucking and jerking violently. After she pulled off from the stop sign, she crashed into a large SUV. The consumer stated she saw the SUV pass, so she purposely waited so she could make a left turn, but ended causing severe damage to her vehicle.

- Monte Rio, CA, USA

problem #39

Jul 242010


  • 63,000 miles


While heading up my driveway in my 2004 Prius, the car began to accelerate, I threw it into reverse and turned back toward my garage where it crashed thru the wall.

- Bellingham, WA, USA

problem #38

Jul 072010

Prius 4-cyl

  • 92,345 miles
1) events leading to failure: Post-"90L campaign" recall maintenance performed on 2004 Toyota Prius, vehicle driving at ~15 mph on a flat clear road. 2) the failure: Unintended acceleration observed. Accelerated, without accelerator depressed, to ~27 mph. Brakes successfully applied. Release of brake resumed unintended acceleration. "rode the brake to deliver vehicle to safe parking location. Consequence: Unintended acceleration controllable by braking. 3) nothing has yet been done to correct failure. Vehicle has not been driven or moved since failure, since deemed unsafe to drive by owner pending any useful response to notification of this incident by Toyota Inc. (no useful response as of yet.) the dealer was unable to duplicate the consumers concern. Updated 08/30/10 update IVOQ 09/01/10

- Mesa, AZ, USA

problem #37

Jul 102010


  • 45,000 miles
The automobile was stopped at a intersection and the pavement was wet from a light rain. I applied normal pressure to the accelerator and felt the car move forward as expected. Then the problem occurs, I felt the tires slip due to a lost of traction with the wet pavement. At that point the anti-skid/traction control engaged and stopped all power to the wheels. This left me part way into the intersection and no power to the wheels. Pressing the accelerator even to the floor resulted in no change, no motor or engine power. This has occurred three time in similar conditions, with mixed results. Twice the problem could of lead to an major accident. In summary this problem disable the drive train in a unpredictable manner that takes the driver out of the process.

- Houston, TX, USA

problem #36

Jul 132010


  • 44,500 miles
2004 Toyota Prius accelerates due to gas pedal getting stuck in the floor mat. This morning I was driving my Toyota Prius 2004 that I bought from the original owner who mentioned all recall issues were addressed by Toyota dealership. He mentioned the dealer shaved off the gas pedal to make it shorter. But today, while on I 495 going eastwards just before entering the hov lane, I pressed the gas pedal all the way down to over take another slow vehicle. The car engine kept raising noise, and car started to accelerate on its own. I braked, the car slowed a bit but engine kept running fast... I realized this is potentially same issue that people reported on press and with lot of struggle trying to brake and slow down, realized and put the car into N, neutral position. I am lucky to know this from media reports, otherwise I would have been another dead guy on a Prius! while I was still on highway, needing to maintain speed I put the car back on drive mode, D and the problem continued. I realized, I can lift the gas pedal with my left foot, and succeeded in untangling the pedal from the floor mat. After I did that it was fine. I arrived at work, but with extreme shock and disappointment. I am wondering how this problem can still remain after a recall repair is done on this vehicle. This is completely unacceptable and my life was in total risk and I survived today purely because of my technical skills and knowledge about this car issue. I am an engineer in profession, a mechanical engineer with a masters degree and I understood how to react. If it was for my other family members in this situation the outcome would have been totally different. I am very very disappointed with Toyota corporation and also with you, the NHTSA for not making sure that all Prius out there are safety compliant. This is really terrible !...because its a known issue, and old issue that should have been corrected. [xxx] information redacted pursuant to the Freedom Of Information Act (FOIA), 5 U.S.C. 552(B)(6).

- Astoria, NY, USA

problem #35

Feb 072010


  • miles


2004 Toyota Prius. Consumer states acceleration problems when the consumer attempted to stop at a red light, the vehicle continued to accelerate. The consumer swerved into the next lane to avoid hitting the vehicle in front of her. The motor revved and the vehicle began to fishtail. Then the motor returned to normal and the vehicle stopped. The consumer called the dealership to make an appointment, but was told the vehicle was not a part of the recall and the diagnostic testing would not be covered by Toyota. The dealer was unable to find anything wrong with the vehicle.

- San Mateo, CA, USA

problem #34

May 282010


  • 102,595 miles
The contact owns a 2004 Toyota Prius. While driving at approximately 55 mph the contact depressed the accelerator pedal and the vehicle surged forward. The vehicle would not stop until repeated pressure was applied to the brakes. The contact called the manufacturer who stated that the issue was not a big deal. The failure and current mileages were 102,595.

- Rockton, IL, USA

problem #33

Jul 152005


  • 14,000 miles
Within the first year of owning my 2004 Prius I experienced unintended acceleration. In the old days (I'm 71) if you experienced unintended acceleration you would right off check your gas pedal and floor mats. That kind of problem wasn't all that uncommon when you owned old cars. If you didn't find a problem in the area of the gas pedal you would pull off the side of the road and usually find the throttle spring on the carburetor messed up in some way or something along those lines. Well, when it happened on my Prius going about 40 mph on a stretch of road not so far from my home I instinctively checked my floor mats and throttle shaft for interference or sticking. No problems found. I got the car stopped - don't remember how (with years of driving experience you instinctively try things until you find something that works). Anyhow, after that I went directly to mytoyota dealer where they checked it out but found nothing. The problem never occurred again. Now I see this claim that it's not an electronic problem on this drive-by-wire car. I don't believe it. If you think about it, if it happens just one time on my one Prius in thousands of miles of driving, that makes an incident of this sort pretty rare, rare enough to where it's unlikely to occur under controlled tests (it would be infinitely easier to find the proverbial needle in a haystack). Virtually every microprocessor controlled product I've ever used has required a reset now and then. Usually there's no indication of why the product locked up (or whatever). If you use satellite tv, a dss modem, or own a pc I'm sure you've experienced it. Why it should be any different with car microprocessors is beyond me. The answer is for the government to require some kind of fail-safe apparatus on every drive-by-wire car in the future (I see Toyota is already implementing this concept into their 2011 cars). Heck, my life or the life of my children or grandchildren might very well depend on it.

- Albuquerque, NM, USA

problem #32

Apr 052010


  • 74,000 miles
The 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.

- Hanover, NH, USA

problem #31

Jan 242010


  • miles
S10 appropriate handling re Toyota vehicles recall, owner of a 2004 Toyota Prius experienced sudden unintended acceleration. The consumer stated as he was driving, he approached a slower moving vehicle, but when he attempted to apply the brake, the vehicle instead accelerated. As he hit the brake harder, the vehicle accelerated even more. The consumer had to avoid an accident by crossing over the double yellow line into oncoming traffic. The consumer managed to avoid an accident and quickly moved back over to the correct side of the road. The consumer stated the gas pedal was not stuck as Toyota is claiming there is a quick fix and placing the blame on the accelerator pedal. Prior to the incident, the consumer stated as he was waiting in a line, with his foot firmly on the brake, the engine seemed to suddenly rev up and the vehicle lurched forward but did not move due to his foot being firmly on the brake. The consumer also stated on several occasions when he hit the brake the radio and air condition would come on. The dealer claimed there was nothing wrong and that the consumer must have hit the radio and climate control buttons on the steering wheel. The consumer believed that the braking system influences the electronics or computer and causes the acceleration of the vehicle.

- Doylestown, PA, USA

problem #30

Mar 252010


  • miles
While driving to work this morning in rush hour traffic, my car suddenly accelerated as I was merging to my left. As I was merging I felt the car accelerate and the decrease in pressure against my foot as the pedal depressed on it's own. I was able to regain control of the car after forcefully stepping on the brakes twice, at which time the gas pedal came back up.

- Whitestone, NY, USA

problem #29

Jan 012010


  • 42,154 miles
The contact owns a 2004 Toyota Prius. He experienced sudden acceleration twice on January 16, 2008 and March 6, 2008. While he was driving at approximately 30 mph the vehicle suddenly accelerated up to 100 mph. He continuously applied pressure to the brake pedal until he was able to bring the vehicle to a complete stop. The vehicle was towed to the dealer. The dealer stated that the vehicle accelerated, because the floor mat was trapped under the gas pedal. The dealer replaced and secured the floor mat. The manufacturer was contacted. The manufacturer stated there were no related recalls. He has not experienced the failure again. The failure mileage was 42,154 miles and the current mileage was 61,000.

- Cherry Hill , NJ, USA

problem #28

Mar 152010


  • 135,000 miles
I was turning my 2004 Prius into a parking garage at between 2-5 miles an hour, applied the brakes as I was going in over a small lip/bump in the pavement, and the car accelerated on it's own. I was lucky enough to swerve and reapply the brakes in time to avoid hitting an oncoming exiting car. It was very scary and I almost hit the other driver. I have never had this happen before. There has been a couple similar incidences where I was braking while coming up to a stop, hit a bump or pothole in the road and the brakes felt like they stopped working for a split second and then seemed to have resumed. It is a strange sensation when you are expecting a stop. The car has always been serviced at a Toyota dealership every 5,000 miles since it was new and will be due again in about 2 weeks.

- Oakland, CA, USA

problem #27

Jan 242007


  • 37,294 miles
I was entering a major highway from a parking lot when the engine suddenly accelerated at full speed. Visibility was good. There was a small pothole so I did touch the accelerator. Next I was in the middle of the highway & hit by a car going 65mph. I do not think I hit the accelerator rather than the brake although that was the only explanation at the time.

- Culpeper, VA, USA

problem #26

Oct 052007


  • miles
The contact owns a 2004 Toyota Prius. While the contact was driving 12 mph she was hit by another vehicle damaging the brake line which caused the contacts vehicle to contunially move after the crash. In order to stop the vehicle the contact had to engage the emergency brake. The contact called the manufacturer and was informed that the vehicle was difficult to stop due to the damaged brake line. The failure and current mileages were not available.

- Kenton, OH, USA

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