I own a second generationprius (2006), and it has the same brake symptoms that are being described by the owners of the 3rd generation model. When I apply the brakes while going over a rough surface, the brakes do not engage for a second or two. This has been the case since I purchased the car new, and I thought it was just a quirky characteristic of the hybrid, so I have learned to compensate by giving myself an unusually large distance between me and the car ahead of me. This doesn't always work, as people cut in front of me when the gap is large. I have not been in an accident, but there have been several near-misses with me almost rear-ending the person in front of me due to this brake problem. I hope the NHTSA is looking at all models of the Prius for this defect. In my form below, I checked air and hydraulic brakes because there is not an option for anti-lock brakes on the drop down box.

- Highland Park, IL, USA

Whenever I drive over rough surfaces the brakes won't engage for a few seconds. On several occasions I almost hit the car in front of me or I drove into an intersection and was almost in an accident. I asked a mechanic at the dealership about it and he said that is just how the car is, so nothing was done. It has been an on-going problem since I bought the car in 2006, so the approximate incident date below is irrelevant.

- Baltimore, MD, USA

I have a 2006 Toyota Prius. When I am braking on a bumpy road, or over a pothole, the brake will cut out for a brief period, leading to a sensation of sliding. This has happened repeatedly. The incident date is just an approximation of the last time it happened. It has happened since the car was new.

- Mclean, VA, USA

If I hit a bump while braking in my 2006 Prius, the brakes give-out and I have re-brake. It only happens at slow speeds, and only when I hit a bump or pot-hole. When I mentioned it to the dealership 2 years ago, they said they were aware of the issue, and I should just re-apply the brakes. It still happens today.

- Boca Raton, FL, USA

I have a 2006 Toyota Prius that seems to have the same braking problem as described for the 2010 models, when I apply brakes on a bumpy or rough road. I notice it most at an intersection in my town - I hit the brake pedal to begin slowing for a red light, the car starts to slow, I hit a patch of rough road, the car feels like it's accelerating (its rate of slowing is less, so it feels like it's accelerating), then the brakes "kick in" again and slow the car. Very surprising the first few times it happened but in three years it's happened so often I hardly even notice it. I didn't associate it with bumpy roads until reading recent articles on the 2010 Prius brake issue. No accidents yet but I hesitate to let others drive my Prius. This problem is not limited to 2010 models! I put Jan 1 2009 as "approximate incident date" because you won't accept this form without a single specific date, but it's been an ongoing problem with this car since at least March 2006 through January 2010. I have no idea if the car has electric or hydraulic brakes so I picked "service brakes hydraulic". very unclear category names for "vehicle information - details".

- Coshocton, OH, USA

2006 Toyota Prius brake failure - car suddenly accelerates forward when braking and running over a discontinuity in the road or wet pavement.

- Aptos, CA, USA

I'm filing this as it may relate to your current investigation of the Toyota Prius braking system. I have a 2006 Toyota Prius with electronic stability control (ESC). I've noticed that, at times when the ESC is activated by a bumpy/slippery road, that attempting to activate the brakes (via the pedal) at that moment (shortly after the ESC has activated, per the dashboard light) will sometimes "fail". the "failure" being that the brake pedal will depress to the floor (often with a 'clunk' noise - maybe the brake pedal hitting the floor?) without activating the brakes. I've found, every time, that releasing and re-depressing the pedal activates the brakes without fail. This has happened on numerous occasions so the "approximate incident date" I've entered is a best guess of the most recent occurrence.

- Arlington, TX, USA

My 2006 Toyota Prius completely loses braking when I run over rough road. This has happened since I purchased the vehicle new in March of 2006. I have always thought the front of the car was light and my wheels were actually jumping off the ground, but with the safety recall of new 2010 priuses for the same problem under the same conditions, I realized this is a system problem.

- Shaker Heights, OH, USA

I drive a Toyota Prius 2006. It has not been the subject of any official recalls other than the map recall. However, I am writing that this car suffers from the same brake defect which has been recently reported on in the newer Prius models. That is, whenever I drive over a pothole or a slippery surface, the brakes disengage as a result of the stabilization system. It occurs frequently, but I have become relatively use to it, such that it doesn't bother me anymore, though I know it is a serious problem. So far I have not done anything to repair the problem, primarily because there has been no official problem with it declared. I hope this changes.

- New Orleans, NJ, USA

2 brake problems: (1) brakes do not work well on snow. I have slid through 3 stop signs since purchased car in 2006. Brake applied but no or very slow response. I try to avoid driving during snowstorms as a result. (2) when braking on wet or uneven (broken pavement, potholes, manhole covers, etc.) roadway, yellow light blinks on dash and car momentarily -- for 1/2 or 1 second -- does not respond to brake pedal. Car feels like it is flying, like you are totally out of control of the vehicle. This has happened at least one dozen times since I have owned the car.

- Clinton, MA, USA

My 2006 Prius also feels like the brakes aren't working correctly when I go over a pothole, similar to what has been described in the 2010 Prius in today's news report. I suspect the problem is not confined to just the 2010 Prius, but all years.

- Syosset, NY, USA

I own a 2006 Toyota Prius. I have experienced dramatic changes in braking deceleration with the brake pedal at constant pressure, but when driving over bumpy roads or potholes (such as those on my home street). The sudden decrease of deceleration is accompanied by an indicator on the dashboard telling me I'm going over bumpy terrain, the braking change lasts on the order of a second. This phenomenon has occurred repeatedly during my ownership of the car, always under similar circumstances. It occurs both at low speeds (e.g. on my street) and high speeds (e.g. on a potholed freeway). Your reporting system asks for a specific date, mileage, and speed at which the failure occurs. I have entered arbitrary values. I emphasize that (1) this phenomenon has occurred repeatedly since just after my purchase of the new car and continued to the present (the car has 50K miles at present), and (2) has occurred at various speeds.

- Oakland, CA, USA

Brakes on my 2006 Prius do not work immediately when applying the brakes when the anti-skid feature is activated. I noticed this shortly after purchasing the car in September 2006. When I read in the newspaper today that the 2010 Prius was exhibiting this same behavior I decided to make sure NHTSA knew this was also a problem with my 2006 Prius since it was brand new. It has happened repeatedly and consistently whenever the anti-skid feature is activated and I apply the brakes. I just thought it was something I had to get used to but now I know it may be a defect. The incident date I provided below is just the most recent incident of the situation.

- Pelham, MA, USA

2006 Toyota Prius. Braking behavior identical to what has been described in the 2010 Prius models. When traveling over a rough patch of pavement or potholes at low or moderate speed, the vehicle braking seems to release. The best way to characterize this is that as the vehicle bounces over the rough pavement during breaking and the weight is applied and released from the wheels due to the up/down motion, the brakes release and re-apply inconsistent with the steady pressure I apply on the brake pedal. This is beyond the behavior expected by the ABS. No accident or damage has yet occurred, but the behavior is disturbing. Not meaning to pile on with the ongoing troubles with Toyota, but the description of the braking in my 2006 vehicle is identical to what is described in the 2010 Prius model.

- Seabrook, TX, USA

I own a 2006 Toyota Prius- I have had several incidences where I put my foot on the brake at low speed and the brakes took a very long second to engage- it has occurred when I have been turning the wheel and also when moving in a forward direction I have put one date below - however it has happened many times since I have owned the car.

- Asheville, NC, USA

You need to broaden the investigation of the 2010 Prius braking issue to include at least the gen II Prius (2004-2009). What's been described in the press (since several months ago) regarding reports of braking problems on the 2010 Prius has been a problem for me with my 2006 Prius since I got it. I checked and posted to priuschat.com on it years ago, and found many others have experienced the same problem. Note that the common wisdom on the site is that the issue is actually "traction control" that aggressively disengages the drivetrain when the wheels spin at a significant differential, in order to protect the drivetrain. This action disengages regenerative braking. The switch to conventional friction braking has a delay, and causes the (quite startling and scary) absence of braking for a brief period. This explanation is consistent with the fact that an analogous problem happens for acceleration, when hitting uneven pavement, potholes, etc. I.e., acceleration is momentarily disengaged. (this, itself, can be quite startling if one is pulling out into traffic, and suddenly loses power.) I marked the incident date as the approximate time I purchased this vehicle. As I said, it has been a problem since the outset. Before I became acclimated to the behavior, I probably experienced a startling loss of braking roughly once per week or so. Once I came to recognize what was happening, I learned to ease off the brake pedal myself, as I approached a problem feature in the road (like a pothole or manhole cover) in order to avoid it. Since then, I only rarely miss something, and experience the loss of braking problem perhaps once every few months. The matter would definitely be perceived as serious by typical drivers -- it's a heart skips a beat, worry that you're going to hit the car in front of you kind of feeling.

- Miller Place, NY, USA

Toyota 2006 Prius brake problem...I have always had the problem that jessica yellin outlined on cnn. As an engineer myself let me describe what the issue is. The short answer is that the anti-lock brake system conflicts with the traction control system on bumps and slippery surfaces. If you are braking and hit a pot hole or series of bumps (causing a wheel to spin slower than the rest) the anti-lock brake system kicks in and disables the brakes in an unacceptable manner. A yellow "traction" light on the dashboard flashes during this even, which lasts about a second unless further slipping occurs. I understand the goal of anti-lock brakes, the implementation on this car is just plain poor and unsafe. I have tapped other's bumpers in situations that I should have been able to stop in. At first I complained to the dealer, but after driving other's Prius cars I found out they all do the same thing. (at least 2005 and 2007 models.) I have driven this car since September 30, 2006...and have over 40,000 miles. I am sure that this issue could be addressed by upgrading the firmware in the vehicle. Or, disable anti-lock brake system so they work when I step on them! I have had no accelerator problems.

- Randolph, VT, USA

My wife and I own a 2006 Prius that we purchased new. Our Prius has the exact same braking problem that I read about today involving the 2010 Prius that you are starting to investigate. Applying the brakes while driving over bumps will cause repeated momentary lose of braking. I never reported it to the dealer. I just thought that was the way it was and was careful about braking on rough roads.

- Paw Paw, MI, USA

After going over significant bumps or potholes, occasionally brakes hesitate to catch. Began within a month of purchasing vehicle. Reported to dealer, test drove for approx. 5 minutes and could not repeat so they ignored my complaint. Problem persists, but to date have not had vehicle fail to stop. Have over 80,000 miles on Prius.

- Plymouth, WI, USA

I experience momentary loss of braking capability while traveling over an uneven road surface, pothole or bump with an earlier model Toyota Prius. My Prius is a 2006 model (2nd wave). This occurs every time I go over one particular spot in my usual commute, and any other spot where the road is rough.

- Camarillo, CA, USA