Toyota adds 2010 Prius braking problem to the list, recall possible

Consumer Reports News: February 04, 2010 04:42 PM

Since the U.S. and Japanese governments yesterday launched an investigation into braking problems with the 2010 Toyota Prius, news reports suggest Toyota will recall 270,000 cars to correct the issue.

In a statement, Toyota said, “…customers have complained of inconsistent brake feel during slow and steady application of brakes on rough or slick road surfaces when the anti-lock brake system (ABS) is activated in an effort to maintain tire traction. The system, in normal operation, engages and disengages rapidly (many times per second) as the control system senses and reacts to tire slippage. A running production change was introduced last month, improving the ABS system’s response time, as well as the system’s overall sensitivity to tire slippage.”

To understand what consumers are experiencing, we have mined the National Highway Traffic Safety Administration (NHTSA) complaints database for examples from the Office of Defects investigation.

  • I have a 2010 Prius which I bought in August 2009. On several occasions, approximately 8-10 times, I have been braking at slower speeds when coming to an intersection. When I put my foot on the brake and the car happens to hit a bump or hole in the road and the car noticeably surges. My foot is not on the accelerator and this has nothing to do with the floor mats because my floor mat is pinned to the floor of the car. The most recent time this happened with 12/28/2009.
  • I have a 2010 Toyota Prius, and am shocked that this car was not included in the gigantic Toyota recall. Why? Becase [sic] the 2010 Toyota Prius exhibits brake failure and sudden acceleration when slowing down on bumpy roads. For example, if you’re slowing down towards a red light, and then all of a sudden you hit a pothole, the car will suddenly accelerate and may cause a crash with the person ahead of you! This happens all the time and is extremely dangerous. Thousands of 2010 Prius drivers worldwide are also having this brake failure/sudden acceleration issue with their 2010 Prius [sic] as well! Take a look at just a few of these discussions which are taking place, where people are having uncontrollable sudden acceleration with the 2010 Prius. Will the NHTSA please do something about this?
  • I have a 2010 Prius. when I hit a pothole while stepping on the brake, the brakes let go. I have to rebreak [sic]. The car actually seems to speed up. It is very frightening. I have taken it into the dealer. They say it is the anti-lock brakes. I have had anti-lock brakes before and never have had that kind of problem,
  • I would like to add my report to your other complaints about 2010 Toyota prius brakes. I purchased mine in July and since then have experienced 4 (four) instances of this problem. In each case, I was decelerating with the brakes steadily applied, and rolled over a bump or pothole in the road. At that moment, the brakes stopped working, or the braking power was severely reduced, and the car felt as if it lurched forward. Applying more pressure on the brakes when this occurs does cause the braking to resume, but there is a delay of perhaps 1/2 second. I have not had an accident so far, but if i were behind another car which was also braking when this happened, there is a high likelihood that my car would smash into the other car's rear.

NTHSA has stated that the complaint records involve four deaths. The complaints can be found on the Web site of NTHSA’s Office of Defects Investigation.

Eric Evarts

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