While traveling in a rain storm at 17mph, I tried to engage the brakes to prevent from crashing into an 18 wheeler and the brakes did not work. I repeatedly tried to stop the car and the car was accelerating even thought I was applying the brakes not the gas. The car would not shut down, go into park or neutral. I did crash into the 18 wheeler because the engine was accelerating and I wanted to stop.when I crashed the airbags did not deploy. Even after impact the car was still accelerating like it was trying to push the 18 wheeler. Eventually the car powered down after repeatedly pushing every button possible. I had the car towed to a Toyota dealership. I phoned your hotline but the VIN number I gave had a number that was wrong my prior confirmation number is 10542285. Toyota is aware and I am waiting for them to call me back.

- Pearand, TX, USA

The contact owns a 2012 Toyota Prius. The contact mentioned that while driving 35 mph, the brakes failed to respond. The vehicle was taken to the dealer. The technician was unable to diagnose the failure. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure mileage was 4,600 and the current mileage was 4,900....updated 11-01-13

- Irvine, CA, USA

The contact owns a 2012 Toyota Prius. The contact stated that while driving approximately 25 mph and making a turn, the brakes failed to respond upon engagement. The vehicle came to a stop after the contact applied the brakes several times. The vehicle then resumed without the brake malfunction. The vehicle had not been diagnosed or repaired. The manufacturer was not notified of the defect. The approximate failure mileage was 12,000. The VIN was not available.

- Buffalo Grove, IL, USA

I was exiting the park and my Toyota Prius' brakes failed, careening me onto a major thoroughfare (South orange avenue) on a hill, while my car began accelerating. I hit the park button and my car slowed until I was able to get control again and turn up a hill to a stop. When I turned my car off and on again, the brakes were functioning normally.

- South Orange, NJ, USA

My Prius V five was purchased in August 2012. Location of the car is nw of wa state where temperatures are currently in the mid 50S (and below) with high level of humidity. Since the beginning of October 2012, I'm experiencing a noise that would best be described as an "OWL hooting." My problem is especially noticeable after the car has parked for an extended amount of time (eg. In the garage overnight). Sometimes, merely parking for 10 minutes on the school's parking lot is enough to make the noise appear again. The "hooting" definitely "oscillates" with the rotation of the tire and emanates from my rear right side, but is especially loud when making left turns. The noise disappears after driving a few hundred yards, but is loud enough to turn heads. I'm able to reproduce this problem every single morning since October 2012. The service techs were able to confirm the noise, but couldn't repair the defect. Instead, an open case/ticket was submitted to Toyota's headquarter.

- University Place, WA, USA

The vehicle emits a repetitive 'woo......woo.....' that varies with speed/wheel revolution (something rubbing during each revolution). To the best of my ability to tell, it sounds like the groan is coming from the rear-passenger side. The sound is usually present after the car has sat overnight or after prolonged parking and last for 100-300 feet of driving. I've even heard it after four hours of being parked at work. It will typically make this sound for a few days after a rain event. The sound has occurred in both forward and reverse and with the emergency brake on or off prior to departure. I purchased the vehicle in April and have heard it all the way to the present. During a tire replacement I made note of the issue to the dealer, who attributed it to rotor oxidation. I responded that I've heard the grind/groan of rust being worn off the rotor when first apply the brakes, and this is not that sound. I went in with a recording on my phone and the technician agreed it wasn't rust. They repaired the tire and tried to reproduce the condition without success. They did tear down the brake and found nothing out of the ordinary. The fact that this issue persists on multiple vehicles of this model is indicative of a manufacturer's defect that should be addressed.

- Marion, MA, USA

Vehicle is parked outside, and during morning cold start, the vehicle produces a moaning/wooing sound for approx. 50-75 yards with vehicle moving under 25 mph. The sound is being generated from the front wheel wells. Sound generated is related to vehicle speed. The faster the vehicle moves, the more frequent the sound being produced during the first 50-75 yards. Strange sound is gone after that, and does not return until the next cool/cold start. Owner took the vehicle back to dealership for inspection, and dealer took off the front wheel to inspect brakes, wheels, and tires, and was not able to locate or reproduce the problem. Abnormal sound is only produced during morning cold starts and when vehicle is left to cool(I.e. parking lot at work).

- San Diego, CA, USA

Repeating several-second groaning or grinding noise heard from rear wheel area upon startup motion. The noise is severe and sounds like low-pitch metal grinding. It's potentially brake related but could be suspension bushings or other components rubbing against one another. It does not sound like typical brake glazing. The noise occurs in all weather conditions and typically after vehicle has been sitting for several hours or overnight. Noise continues for several minutes at stop and start. Noise is loud enough to startle an experienced driver. The absolute severity and indication of the sound is enough to question safe ongoing functionality of braking and/or suspension systems. Multiple reports are documented online at priuschat.com. Toyota does not appear to have a fix or resolution at time of writing, 10/2012. This is for 2012 Prius V model five.

- Pasadena, CA, USA

The contact owns a 2012 Toyota Prius. The contact stated that while depressing the brake pedal, the brakes locked up. The contact continued to depress the brake pedal and shut the vehicle on and off by pushing the start button. The failure occurs intermittently. The contact also noticed the brake pedal drops to the floor board about a half inch when starting the vehicle. The manufacturer was made aware of the failure and a complaint was filed. The vehicle was taken to the dealer who was unable to diagnose the failure. The vehicle was not repaired. The approximate failure mileage was 3,000.

- Spanaway, WA, USA

As I was approaching a turn I began to brake and the brakes failed. I tried pressing the brake pedal harder and making sure that I had proper foot placement and it felt like the car accelerated at that point. Since the car was not slowing down I was unable to make the turn and ended up crossing the road diagonally and going up onto the curb. Once the car was over the curb and in the grass the brakes finally engaged and the vehicle came to a stop.

- Portland , OR, USA