Which parts fail
Components named in complaints (electronic stability control and traction control).
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 automatic braking system (ABS), vehicle stability control (vsc), brake light, and brake system warning lights (4) on the Prius all came on and vehicle became very unstable while out of town. The owner's manual indicated that the dealership should be contacted and car should be taken in immediately for service. Since no dealership was available at the immediate location, the car was driven home (60 miles) in very unstable conditions. Upon bringing it to the dealership I was told it was a miracle nothing bad had happened because the "computer skid assembly" needed to be replaced at a cost of $1570.97 for just the part!!! I found it very interesting that the part was readily available as if I were replacing an oil or air filter. After confirming the cost with other dealerships, I consented to the work to be performed. Is this just another "built in obsolescence" feature? …
I am the first owner of this 2005 Prius and have kept up with all maintenance and recall issues. This is my first complaint. On a perfectly fine weather day, I was driving my usual route home coming to a line of stopped cars in the left turn lane on a relatively flat, unbumpy surface street and was about 1 car length from the stopped car in front of me when I applied my brake. To my astonishment, with the brake fully engaged, my car kept going forward as if I had no brakes and rear ended the car ahead of me. Luckily neither of us were hurt as I had already slowed down for the stop. There was no damage to my car (my license plate holder hit her bumper and caused a couple of paint chips on hers, which will probably cost me thousands of dollars to repair) but I can tell you I was thoroughly shaken up. No emergency lights or code lights went on inside the car. …
I started the car and the speed indicator didn't illuminate. I thought it was a lightbulb or something that that had gone out since the car drove like normal. When I got to my destination I tried to turn off the car but it didn't turn off. I called the campus car service, by the time they got to me (about 30 minutes) the car had turned off by itself. This has happened about 8 times since. There was a recall on this very issue where Toyota admitted that high milage Prius' were experiencing this problem. The recall ended in 2013. I just don't understand how a know issue is no longer being fixed when they clearly stated that it affects high mileage cars. So people like me who's cars haven't reached a 'high mileage" during their recall period are basically told to guess how fast the car is traveling?
My Toyota Prius 2005 has the same braking issue as described in the media today for the 2010 model. In addition, the skid control causes a sudden power loss during acceleration in similar situations to the problems described with braking failures in the 2010 model (potholes, even small bumps in the road, rapid acceleration around curves, in addition to when there is ice on the road) that reportedly has been fixed. Although the complete power loss lasts less than a second recovery of power is slow enough to have stranded me in front of oncoming traffic waiting for acceleration in a number situations where there was no risk associated with loss of traction. I contacted Toyota several years ago and tried filed a complaint (I was really persistent), but they refused to recognize this as a design flaw saying only that the vehicle was functioning as designed. …
When approaching a light, I changed lanes into the left turn lane, applied the brake to slow down, let up on the brake to go over a depressed area where a pipe was being replaced and the road repaired. I then applied the brakes firmly to stop the vehicle. Unfortunately, nothing happened. The traction control light went on when I went over the bump and it took about 2 seconds of heading towards the back of a truck for the breaks to engage at all. When they finally engaged, the car stopped very quickly (as I would expect) and I was almost rear ended by the person behind me. I have had the brakes not engage on one other incident that also involved switching lanes and a bump. Traction control and ABS on this Prius need to be replaced with something that will not kill. I was very disappointed that the "braking problem" was "limited" to 2010 priuses. It is not. …
I first reported this to Toyota March 10, 2010. I did so after talking with a coworker who had a 2010 Prius. I have a 2005 Prius. We both experienced the same thing. Therefore, I figured I should take it more serious. The Toyota's safety incident number is [redacted] . When going over bumps and hitting the breaks I notice that instead of immediately slowing the car down, the car seems to either not slow at all and seems to accelerate. Knowing that going over bumps can cause a tire to temporarily loose contact with the road surface and that cars can electronically transfer drive from a tire that looses contact with the surface to the other wheel, there May be mixed signals happening. The brakes telling the car to stop, the traction control telling the acceleration to transfer. It seems the acceleration is taking precedence. …
We have noticed repeatedly (a dozen or more times) over three years of owning this car and 100K miles, that as we brake going over a bumpy section of road, the braking system fails and the car actually accelerates for one or two seconds. This is especially alarming when we need to brake suddenly in a curve on a bumpy road as it seems we will lose control of the car. I always brake with my right foot and my right foot remains off the accelerator and on the brake throughout these episodes. Our car is equipped with the vehicle stability system and the passenger notices that the stability system warning light comes on during these episodes. It is not simply that the car coasts when the braking fails, the engine actually sounds like it is revving up and the car noticeably speeds up. Once the bumpy section has been passed, normal braking resumes. This has nothing to do with the floor mat. …
2005 Toyota Prius loss of control over vehicle after skidding over ice or snow, traveling on local road. The car went over snow that had been shoveled to that area, or fallen from a truck. The car immediately turn sharply to the left and then right, repeating this weird action about 4 times, gathering more speed with each movement. Finally, I applied the brake with force and narrowly missed a tree by about 6 inches, and a parked van. I landed on top of a heap of soft snow, that must have been plowed into that spot, which kept the car from moving because the wheels had nothing to grip . Up to now the vehicle had performed well, with the exception of the small battery that failed when the vehicle was only a few months. I had to pay out pocket for the replacement. The vehicle now has 119,000 miles. And now I will go shopping for another brand. …
2005 Toyota Prius--experiences braking and handling failures when braking on uneven or wet surfaces. When we are braking and hit a pothole, gravel, railroad tracks or wet surfaces, the car feels as if we are losing control of it, and braking seems to temporarily stop. The "skid danger" light comes on, even at very low speeds. This happens nearly every time we brake under these conditions. Also, at idle (ie. Stoplights), the car will frequently lurch forward slightly, even with the brake pedal fully depressed, especially when engine transfers from electric to gas. We were told early in our ownership that this is normal "dieseling". …
The traction control on my 2005 Prius is dangerous. This is a well-documented problem (www.priuschat.com) . Toyota will not fix the problem. The problem is that when the car hits even a small patch of water and the tires slip, the engine shuts down for way too long. So, when accelerating rapidly from a stop, for example, if the tires happen to spin, the car just coasts for way too long. This is especially dangerous when accelerating rapidly onto a freeway from a stop, which I have to do frequently. My entrance onto the 101 in hollywood requires this type of acceleration, and I dread it every time I do it. I own a 2005 Prius. Do a search on www.priuschat.com using the term "traction control" to see many other similar complaints. This is the first complaint I have ever filed, and I really hope something can be done about it.
Traction Control complaints in other Prius years
Frequently asked questions
How common are traction control problems on the 2005 Toyota Prius?
NHTSA has 38 complaints about the stability & traction control of the 2005 Toyota Prius, 4% of the model year's 1,051 complaints. The component named most often is automatic (asc) (2 mentions).
Is there a recall for 2005 Toyota Prius traction control problems?
No. NHTSA lists no stability & traction control 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 traction control problems start?
Half of the complaints with a recorded mileage happened before about 67,000 miles, and 32% before 25,000 miles.
Is it dangerous?
Owners linked 1 crash, 0 fires and 0 injuries to stability & traction control 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.