Consumer Complaints


Fail datemilesoccurencesPurchase date
UNKNOWN OR OTHER
01/21/201329995
 Today, 1/21/2013 at approximately 245pm while drive back from disney with my family on the florida turnpike(mile point marker 294 nb) at approximately 65-70 mph our 2010 prius suddenly lost power and check hybrid system came on. mind you i was traveling on a major road when the car suddenly kept decreasing in speed and i just turned on to the median and the car rolled to a stop. luckily there was a florida safety patrol behind me who put on his flashing lights until i was safely off the turnpike. car would not restart and had to be towed. car arrived at xxx(dealer) toyota at 502pm and i am awaiting a call back on the problem. this is a safety issue. also, there was no warning before the car failed. thank you. this is what i filed with toyota minus identifying data
11/20/201266395
 While making a u turn the vehicle lost power and the check hybrid system warning illuminated. the car died in the middle of the road. the dealer claimed that there was oil in the throttle body caused by overfilling and this is a common occurance with oil overfills on prius vehicles. the last oil change had been 8,000 miles and more than 2 months previous. the place that performed the oil change agreed to look at car and clean the throttle body. they also checked the oil and made sure it was correct level. three weeks later the same thing occurred. this time the car lost power and the check engine light illuminated. the car died on a freeway transition over pass and we were stranded on the freeway in a very dangerous situation. the car was towed to another toyota dealer and they claimed it was the same thing. the oil change place says absolutely no way is this the problem since they looked at it very closely the last time. i requested toyota to send out a field representive to confirm that this was the cause. they refused. computer codes p3190 and p0a0f hv.
10/06/201230000
 Panel light dimmer inoperable when parking/head lights are turned on (i.e., there is no display on instrument panel for current speed, fuel volume, fuel consumption, etc. when driving with head lights on). this similarly affects the audio/hvac display.
07/18/201226500
 The unintended acceleration accident happened on 7/18/2012, ~6:20pm at company
01/03/2012
 The autodim rearview mirror does not reduce glare from headlight of cars behind my car. autodim functionality is not affected by turning the autodim feature on or off (it is the same either ways). the only option i have to prevent glare hitting my eyes is to turn the mirror away so i do not see anything. toyota customer service says that i should have it checked by the dealership. the dealership shines a flashlight on the rear view and reports that it is working fine. the problem is that the shape of the car's rear glass and spoiler prevents the headlinghts from hitting the sensor on the auto-dim mirror.
07/30/201110000
 Having a car accident on highway. this accident raises the concern about safety issue of toyota prius.one part of main battery cable underneath the car was not well protected or covered. when a solid objective right hitting the cable with blast sound , the cable was broken apart., we lost all the power, the car totally was dead on the highway.we have 3 people in the car,my 85yr old mother,my wife and me.it is horrible.
05/07/201020000
 I was making a sharp right turn to pull into a parking space, slowing to a stop. the car suddenly and unexpectedly accelerated forward out of my control. i applied the brakes as hard as i could, with no response. as the car was racing into a tree, i shut off the engine by pushing the power button to off. the car knocked down a tree and came to a stop on top of it.
06/11/20116525
 I was driving with to passengers on the new jersey turnpike at 65 mph when i heard a loud noise from under the car. the plastic front engine cover had come loose and was dragging on the pavement. a aaa mechanic removed the part and the toyota dealer is replacing it at not charge. i think it is a safety defect.
05/02/20111
 2010 toyota prius. consumer writes in regards to rapid acceleration issues *tgw the consumer wants to know did the investigation into this matter examine the interrelationship between the accelerator, braking system and cruise control. *jb
04/15/201145000
 After approximately 4 oil changes the oil access door breaks off the vehicle. the oil has been changed 9 times in my prius and after 4 oil changes the oil access door has now broken off twice. each time i heard it break loose like i drove over some debris and i could see it in my rearview mirror go flying across the highway lanes. the oil access door does not have a hinge. it is all plastic and is bent/folded to gain access to the oil filter and drain plug. i changed the oil the first 4 times and the dealer complained i was doing something wrong. the dealer was reluctant to replace the entire engine undercover assembly, stating they would only do it one time. the dealer changed my oil the next 4 times and it happened again right before i scheduled my 5th oil change. after the second occurrence, i retrieved the oil access door to confirm since the vehicle is so low you cannot see it under the car unless it is raised up.
03/11/201123002
 Dear sir or madam, a few days ago i found abundant evidence of mice activity in the cabin of my 16 month old toyota prius. after some internet research i found out that this is unfortunately an extremely common problem with prius model cars and other toyota models. the presence of rodents in the engine area is of course unavodiable but this is the first time i hear about the car design allow mice to easily move into the cabin. this obviously has severe consequences: i already have to replace the air filter and the padding behind the gloves compartment and i am not sure if any other parts have been chewed away. more importantly this is certainly a health and safety concern. i have to get the car detailed and the air system flushed to avoid toxic contamination from mouse excrements, and this endangers me every time i drive: a mouse crawling in the cabin of the car while i am driving is a major safety issue! it appears that the placing of screens in as few as 4 parts of the air system would stop the mouse access to the cabin, but toyota, both my local dealer and the national service center, claim there is nothing the can or will do, and that, despite the abundant evidence to the contrary, this is a normal occurrence in all cars. many people have posted online about mice and rodents in their prius cars. a feel this is a major safety issue with the car, and i am extremely disappointed that neither the local dealer nor the toyota corporate services are willing to helo me solve this situation and prevent it from happening again. i think the consequences of this design defect should be covered under the warranty and toyota should design a scree part to cover the vents where necessary to prevent this from happening in the future.
11/05/2010
 Gas pedal does not accelerate when foot goes down on it 4 times -- i do not have exact dates 1. early november, 2010 1 incident 2. january, 2011 2 incidents 3. unknown unknown 1. coming down the 405 at the 101 interchange, my gas pedal did not propel my car forward. i coasted to the side, turned off the motor, started again and all was fine. i reported it by phone and got an appt. to have the car checked. the dealer said there was nothing wrong. 2. it happened again as i was coming down the 101 into camarillo. i stopped, restarted and went on my way. 3. it happened again but not on an incline. i was going about 10 miles an hour on a flat parking lot. gas pedal did not respond and i created a traffic jam because i could only coast into the parking garage. here are my notes regarding this problem made calls to toyota corporate totally unresponsive- take it to dealer and leave it there or just consider it reported . there were calls to the dealer and corporate regarding 3 of the incidents. toyota customer service the car was checked 3 times- once after the first incident and then the dealer brought in a company inspector - each time they found nothing wrong. they told me that the
02/08/20111500
 2010 toyota prius-while approaching stop light with brakes slightly engaged, left front tire struck a pot hole approximately 15 in diameter and two pavement layers deep. vehicle brakes got soft and car accelerated briefly for less than one second. braking then returned to normal feel and acceleration ceased.
12/18/201010870
 2010 toyota prius was placed in parking in my home garage, as i turned off the heating switch to the seat, the car rolled forward on its own and hit a work bench chair in front of the vehicle. no personal injury was sustained, but the car had some dents to the front end,
11/16/20101500
 My wife was driving our new 2010 prius home on 16 nov 2010. as she was turing the car into our driveway at approx 5:30 pm the vehicle lunched forward at great speed on its own. we have a long driveway, it took her about 30 to 40 feet the get the vehicle stopped. while pressing on the brakes the drive tires kept spinning and left rubber marks in the driveway. bought the vehicle from rick hendrick toyota in sept 2010 in fayetteville, nc.
11/05/20105600
 My 2010 toyota prius would not start after a brief 45 minute lunch with friends. when i released the parking brake and let off the brake pedal i didn't know the car was stuck in nuetral. this error was on the dashboard malfunction when parking, park in a flat place and apply parking brake securely. when i let off the brake the car rolled back into the middle of the parking lot. i had two coworkers in the car with me; they got out and pushed the car out of the way to a flat location. car still was disabled. i called toyota roadside assistance and waited an hour for a tow truck; after about 45-50 minutes of waiting i was hit by a woman that wasn't paying attention; she backed into the side of my disabled car. i was pressing on the horn and she didn't hear. the impact must have freed some stuck componant or something because 2 hours later when the tow truck finally came, the car worked again; no warning lights etc. toyota looked at the car and says there is nothing wrong. i took a photo to document the warning message (plus have 2 witnesses).
10/07/20101800
 I own a new 2010 prius. it has 1800 miles on it. while driving with someone else in the prius, there was a braking problem. we both felt a loss of braking by the prius when i was braking for a right turn and went over a bumpy section on the road surface. the prius experienced a momentary complete loss of braking over the bumps. it felt like we actually accelerated for an instant. in any case, the brake pedal was engaged firmly the whole time. the prius then slowed down normally, and i made the turn at the corner. but we both looked at each other in surprise at what we felt during that braking event leading into the turn. i called the dealer and had them look up the computer patch history on this car. the dealer stated that all the computer patches had already been applied to this car before it was delivered as new. so far, this has only happened once. i have been driving the new prius for only 1800 miles. it was purchased new off the dealer lot aug 2010. it happened in oct 2010. extreme loss of braking over bumpy road surface. i have many years of driving experience in many types of cars on many different road surfaces. i have never experienced this type of momentary complete brake loss before.
06/06/201010000
 2010 toyota prius, no accidents, but close calls. when i am slowing to a stop, and if the vehicle hits a rough spot in the road, for example a pothole, the brake pedal lowers slightly and the car appears to have the anti lock braking take over and the car speed decreases slowly under the control of the abs and may not stop in the remaining distance to a stop sigh or traffic light. at least 4 times, 3 since the software update for my car, i have been stopping and within about 20 feet of the stop sigh there was a significant bump or pothole and with my foot on the brake continuously i noticed that the brake pedal depressed slightly and my rate of slowing decreased and my car drifted past the stop sign. this all happend with my foot still on the brake. i told the toyota dealer about this and was informed that it is the way the car is designed, that any time that the computer senses a wheel slip, the abs takes over. but on dry road conditions, this is problematic because in my area there are often un repaired roads with ruts, potholes, bumps and etc. near the intersections. having the abs take over provides a lag time in the stopping of the car and each time i have gone past the stop sign and slightly into the intersection approximately 5 feet into the path of other vehicles. i am an engineer with nasa and know what i am doing and have been told that this is a design feature, but this feature can and has left me exceeding my planned stopping distance and could have lead to an accident.
10/07/20101800
 I own a new 2010 prius. it has 1800 miles on it. while driving with someone else in the prius, there was a braking problem. we both felt a loss of braking by the prius when i was braking for a right turn and went over a bumpy section on the road surface. the prius experienced a momentary complete loss of braking over the bumps. it felt like we actually accelerated for an instant. in any case, the brake pedal was engaged firmly the whole time. the prius then slowed down normally, and i made the turn at the corner. but we both looked at each other in surprise at what we felt during that braking event leading into the turn. i called the dealer and had them look up the computer patch history on this car. the dealer stated that all the computer patches had already been applied to this car before it was delivered as new. so far, this has only happened once. i have been driving the new prius for only 1800 miles. it was purchased new off the dealer lot aug 2010. it happened in oct 2010. extreme loss of braking over bumpy road surface. i have many years of driving experience in many types of cars on many different road surfaces. i have never experienced this type of momentary complete brake loss before.
06/06/201010000
 2010 toyota prius, no accidents, but close calls. when i am slowing to a stop, and if the vehicle hits a rough spot in the road, for example a pothole, the brake pedal lowers slightly and the car appears to have the anti lock braking take over and the car speed decreases slowly under the control of the abs and may not stop in the remaining distance to a stop sigh or traffic light. at least 4 times, 3 since the software update for my car, i have been stopping and within about 20 feet of the stop sigh there was a significant bump or pothole and with my foot on the brake continuously i noticed that the brake pedal depressed slightly and my rate of slowing decreased and my car drifted past the stop sign. this all happend with my foot still on the brake. i told the toyota dealer about this and was informed that it is the way the car is designed, that any time that the computer senses a wheel slip, the abs takes over. but on dry road conditions, this is problematic because in my area there are often un repaired roads with ruts, potholes, bumps and etc. near the intersections. having the abs take over provides a lag time in the stopping of the car and each time i have gone past the stop sign and slightly into the intersection approximately 5 feet into the path of other vehicles. i am an engineer with nasa and know what i am doing and have been told that this is a design feature, but this feature can and has left me exceeding my planned stopping distance and could have lead to an accident.
08/22/201019000
 We were backing down our driveway in our 2009 toyota prius. as we approached the street our car suddenly made a loud whining noise and started accelerating backwards. before we could do anything, we backed into the car parked across from our driveway. after we collected ourselves, we decided to move the car out of the street into our driveway. the sudden acceleration happened again, but this time my husband reached over and hit the park button and we stopped before we hit anything. i have driven our other two cars down our long driveway since, and we only use the accelerator to start the car moving. after that, we are braking all the way down the drive. the acceleration occurred near the street where we pause to check on the traffic. now that i have checked myself with our other cars, i am sure i did not have my foot on the accelerator pedal at the bottom of the drive, as i brake all the way down. our prius is over at the dealer, and we have filed a complaint with toyota. we are afraid of the car. we did have the car fixed at the recall.
06/24/20102000
 I was backing my 2010 prius out of the garage and the vehicle lunged quickly when i let off the brake. when i pressed the brake to stop, it jerked to a stop. i let off the brake again and it took off. this process of lunging and jerking repeated until i backed all the way out of the driveway and put the car into drive. it scared me. i did some research and a lot of other people have experienced similar issues. in fact, there are 27 pages of people with similar problems at the following link http://priuschat.com/forums/gen-iii-2010-prius-main-forum/65875-braking-in-reverse-16.html#post995838
06/03/20103000
 Grabbing brakes: parked and sat in the car on a slight inclined driveway for some time listing radio. when i started backing up and tried to brake, there was no braking and then clunk clunk noise and car stops, tried again, same thing no braking and then little more pressure on brakes, clunk clunk noise cars stops. there was no way to smoothly glide the car down. this happened around 5 times. during last service i explained dealer about the problem but they could not reproduce it.
09/25/2009
 I have a 2010 toyota prius purchased in july 2009. during ownership i experienced when there was a crease, hole or bumpt in the road when braking - it accelerating and lunges. i avoided situations like that and when the recall came, i took it to butler toyota (also had the floor mat hooks installed prior), on april 5, 2010. they supposedly fixed it. about a week later, i came upon a manhole cover in a road while braking and making a turn so going slow, and the same thing happened. the next day i purposely went through it to test and it did the same thing but lunge into the other lane. i was scared and called butler toyota. they told me to call national toyota to report. they contact butler and i went back in may 21, they did not repair it and shrugged their shoulders saying it's the abs. they offered to have a field tech person come drive my car. i called national again and they seem to be mediating this with butler. i found a report from consumeraffairs.com that this very similar issue was occuring back in 2008 and they called it traction control. no one from toyota has told me this. i want it fixed or a different car. i have a teenage with a permit and if he was driving this and it occurred, he would probably run into someone because it takes you by surprise. i do fear him driving it due to his inexperience and i frankly am concerned and am very cautious as a result.
05/23/20107195
 At about 7:45 am sunday may 23, i was driving west on hamburg turnpike in wayne, gently accelerating to get better mileage, the light at berdan ave and hamburg had just turned green, so i accelerated slowly to about 40 mph. at this point, i hear a shrieking beep and the car lurches forward as the brakes were applied. the dash lights up with the usual message square and the word brake! in the box. i look in all directions and saw nothing until i bounced over the construction plates. the box was gone, and the car resumed normal operation. i was puzzled. i thought it could be the plates. i checked with my son and he reminded me that in the model 5 we have radar crash avoidance. upon further review i wanted more information. i took my son, and a camera, and drove the route again. eureka! in all three attempts, the brakes were applied. i have pictures of the dash, and the plates. did the car perform correctly? the second plate is not flush to the road and sticks out to the left. i think other drivers need to be aware of this possibility so they do not panic when it happens. the crash avoidance system could have been doing its job correctly. i contacted wayne police about the incident and the dispatcher said after consultation
12/27/20096750
 I was on a trip to arizona and when driving in my 2010 prius from flagstaff to phoenix during the evening, the batter display's top segment glowed red many times in the descent from flagstaff. it was a very diffcult to drive to keep the top segment from turning red as the vehicle was coasting and i did not want to exceed the speed limit so i realy did not now what to do. i decided to shift to neutral so the engine was not brakng. hwever in neutral i was wearing out my vehicles brakes which also worried me because of the pssibility of overheating the brakes. i looked in my vehicle manual but nothing as in the booklet about this type of occurence. so i asked my toyota service personnel at rudy luther toyota in golden valley, mn and they had not heard of this problem. he gave me a the telephone number for customer service representatives at toyota and after discussing this incident with many people in customer service at toyota, the end result was that the battery was fully charged and when this occurs the top bar will glow red but this will not effect the battery. i do not know if this is true or toyota is just putting me off but others at the following toyota forum have also experienced this problem. is this a safety problem, i do not know. is it a battery warranty problem, i do not know. but please look at this forum thread and maybe you can discuss this more fully with toyota. http://priuschat.com/forums/gen-iii-2010-prius-main-forum/67994-all-bars-battery-indicator-4.html on the return trip and here in minnesota i have not had this problem occur as there are not many long descents.
02/19/20109950
 I have a 2010 toyota prius with braking problems, which have continued to occur even after i took it to my toyota dealer for the recall repair on february 12, 2010. three times since then the brakes did not engage for about three seconds, when i was trying to stop, on a dry surface that was slightly uneven. this was not the sudden rapid pumping of abs brakes which i would recognize from years of use with abs equipped cars. the dealer saw no problem when i brought it ack to them last week. i am worried it will cause an accident.
01/01/19011
 S10 appropriate handling-letter from regarding toyota problems *tgw
04/20/20107700
 I made a nhtsa complaint on 1/27/10 for abs/unintended accel incidents in my prius2010. supposedly toyota corrected the problem on 2/11/10. on 4/20/10 @ 12:50 pm, my prius accelerated dangerously as i was coming to a complete stop on a slight incline. the car shot forward through a red light on a busy baltimore arterial. i was braking the car and trying to turn it to avoid hitting a concrete wall or cars in the opposite lanes. i turned very sharply,unable to brake the car; i feared it may rollover. my foot was on the brake the whole time. i hopped a curb on the median and clipped a traffic sign. i then parked the car and phoned the police. it was amazing no one got hurt or killed. since this incident occured after toyota said they fixed the problem, i do not trust them or my car. i want a refund for for this car, i will not drive it again:it is a death machine.
04/08/20102520
 Was parking 2010 prius shifted into park and then car started going forward and hit building,driver applying back and car won't stop.
10/23/200910210/22/2009
 Tl*the contact owns a 2010 toyota prius hybrid. the contact was driving 30 mph when he pulled the cruise control lever up to increase the speed, the steering wheel would turn left and when he pulled the lever down to decrease speed, the steering wheel would turn to the right. he took the vehicle to the dealer who advised him to hold the steering wheel tight when increasing or decreasing the cruise control speed and it would not move. the contact was concerned that he had to hold the steering wheel tighter than normal at all times. he called the manufacturer and was instructed to take the vehicle back to the dealer. when he took the vehicle back to the dealer, they informed him that the failure could not be duplicated. the failure mileage was 5. the current mileage was approximately 7,000. updated 05/24/10 *bf the consumer was told to have a firm grip on the steering wheel when using the cruise control to adjust or set the speed of the vehicle. the consumer stated the steering was affected whenever he adjusted the cruise control lever mechanism. updated 06/01/10. *jb
01/01/19011
 2010 toyota prius. consumer expresses discontent regarding innocent lives lost and regarding toyota defects. *tgw
02/25/20107500
 Two occurrences: sudden loss of acceleration without any warning. first time dealership said it was a loose computer connection which they said they tightened and rebooted computer. second occurence, they say they don't know what happened and have contacted toyota headquarters for advice. still waiting after 6 days. concerned about this happening on a very busy freeway. we were on a highway that wasn't that busy and we were able to safely pull to the side of the road. could be disastrous on a busy freeway where everyone is going bumper to bumper at 75 mph!!!
03/20/201011201
 True! gear problem! remember airbus flipping our of control when they came out with fly by wire? the joy stick gear is default to shift into neutral when normal push bring it in to reverse. no way to put it in neutral. i thought the same thing & was in denial until i realize that its impossible to put it into neutral when thing is speeding out of control. don't take it lightly- i did bought a 2010 prius just now & realize - u can't put it - in neutral. i was in denial. also, ventilator fan suddenly accelerates when u try to switch the modes. *dt
03/15/201010000
 My 2010 prius was repaired last month. it intermittently accelerates without my prompting after hitting a bump. this accelreration is as intense as the car seems to allow, as if the pedal were to the floor or worse, and persists for at least one second and has not subsided since the abs actuator ecu was updated in the recall appointment. this acceleration is terrifiying as it can't be anticipated as it does not happen every time i hit a bump, and can't be suppressed by the braking system. i have on several occasions been safely coasting to a stop with the brakes on and experienced this problem. in a few cases this acceleration almost caused me to hit the car in front of me at stop lights. i never did experience the symptoms described by toyota relating to the delayed braking problem, but i fear this problem as much or more.
12/22/2009
 My 2010 prius was delivered on december 17, i took it on two long road trips and used my cruise control on both trips. on both trips with cruise control on there was a surge of acceleration. nothing stuck and when i applied the brakes the cruise control cut off and the car slowed. i have experienced this one other time and again it was interstate driving with cruise control on.
03/01/201012000
 Braking issues in my 2010 toyota prius- after recall fix
09/30/20091899
 I have a 2010 toyota prius - it has 6,000 miles on it. two times the brakes have failed to engage when i have stepped on the brake pedal. it takes appx. 2 to 3 seconds before the brakes engage.
01/01/19011
 Letter from attorney general concerned about the 2010 toyota prius anti-lock brake issue*cw the attorney general was very please that nhtsa is investigating the matter. the attorney general requested that nhtsa answer several questions. *jb updated 03/10/10
08/01/2009500
 This is the breaking problem i
02/02/20105000
 Brakes disengage momentarily when braking on a rough or rippled surface. it gives the feeling the vehicle is being accelerated. uncontrolled travel distance can be lengthly. i have experienced four such instances.
07/12/200956
 While braking and on uneven sufrace brakes feel like they have sropped working and then later catch, vehicle seems to actually speed up. it occures at lease 1+ a day depending on where i am driving and or weather conditiond. speed dosn't always matter, as if coming off expressway and braking, speeds can be 55mph and it still happens. luckily i have not hit any thing yet.
11/01/20092500
 My 2010 toyota prius seems to lose braking power whenever i hit a bump or slick patch in the road. not only do the brakes seem completely disengaged, but the car actually feels like it accelerates forward. i've adapted my driving, but only after i'd ended up in the middle of a couple of intersections because the car shot forward while i was ostensibly braking. fortunately, i've not yet rear ended anyone.
09/30/20094001
 I bought a 2010 prius in august 2009. when i apply the brakes on a bumpy road there is a loss of breaking for a short time. it feels like a surge in acceleration before the brakes work again. i do not know if it is a safety issue but it is very disconcerting. *tw
07/14/2009502
 While braking on roadway that has a manhole or a patch in the asphalt that is not exactly level with the rest of the asphalt, the tires feel like there is no traction and the car feels like it is hydroplaning. i have experienced this while driving on two specific roads and now i try to avoid the areas to prevent the feeling of having no control over the car. it feels like the car lurches forward and has no traction. this happens on dry roads. it is very frightening when it happens. i first noticed it when i first purchased the car in july and it has continued to happen. *tw
01/15/201055008
 I have owned a 2010 toyota prius for approximately six months. during that time i have experienced on several occasions (6-8 times) a feeling that the car is actually lurching forward while i am driving at low speeds over rough pavement and applying the brake. in my case the lurching of the car happens only when i am slowing down to make a turn. it is a frightening experience when you're applying pressure to the brake and your car feels as though it is about to take off. the sensation lasts for a second or two nevertheless it's still as i said frightening. when i first mentioned it to my local dealer the response was that it's the abs brakes and it's normal. *tw
09/01/200910001
 1.i purchased this 2010 prius in august 2010. i have experienced unanticipated acceleration two times since the last (initial) service. once with my husband driving on route 17 and the other time while i was driving on a local road. 2.as i stated in my service paperwork when the car was first serviced, there is a problem with the brakes. they do not stop on uneven road surfaces, such as pot holes, bumps, etc. your service department said that this is caused by the abs and it is ?normal?. obviously there is still a problem. please advise what will be done to correct this issue. 3.when start the engine first thing in the morning (or when the car has not been driven for a while) often, but not always, it makes a grinding noise when starting *tw
02/01/20101
 I've been hearing in the news about the potential of a braking issue with the 2010 toyota prius. just wanted to let you know that i definitely noticed this issue in my new prius. approximately once a month, when i'm braking over an uneven or slippery surface, especially if it is only one side of the car going over the slippery surface, while i'm braking, there is a moment lasting less than a second where it feels like the brakes disengage. (causes your heart to skip a beat when it happens.) i also noticed a separate quirk the other day that i want to pass on to you. i'm not sure if this was done deliberately by toyota or whether this is a defect, however, i believe my speedometer is calibrated so that it reads a speed that is 2 mph faster than my actual speed. i noticed this when i went on a trip and used my wife's tom tom, which uses its gps signal to measure the speed of the car. the tom tom is usually spot on in my wife's acura. in the prius, it was indicating that my true speed was 2 mph less than what my speedometer indicated. i'm wondering if this wasn't somehow intentionally done by toyota to get better perceived gas mileage by the driver. having the car get over the 50 mpg threshold is a big marketing advantage for them. getting over this threshold would be easier if the actual speed of the car was less than the perceived speed. *tw
02/06/201014
 When applying the brakes over a bumpy or metallic surface, there is a uncomfortable delay until the brakes kick in. this has been going on for some time.
02/06/201043081
 I was driving on pleasant grove blvd in roseville ca with a speed of 44 mph. it was about 7:16 pm. on my right a saw a black cat on the curb ahead of my walking, trying to make it's way across pleasant grove blvd. i made an emergency stop (didn't have to come to a complete stop) not to hit the cat. i pushed the brake pedal with full force in order to stop in time. there was no one behind me at the time happily. however, i noticed that the abs system didn't kick in and hence my brakes blocked shortly during the emergency stop. in la i had this happen twice to me that the abs didn't kick in and my wheels block. it's easily repeatable by making a stop that requires a short distance to stop. happily this is hardly ever necessary, but i don't feel safe doing it. i have driven two toyota corollas, they never had this issue and always the abs worked great. in the 2010 toyota prius, this doesn't work well. in addition to the braking issues on the highway, this is another problem with the prius brake. it makes me feel insecure on the road with the prius and i don't enjoy driving it due to these issues. it's just not safe! *tw
02/06/2010161
 The 2010 toyota prius that i have has very grabby brakes when backing up. this usually occurs when backing out of a parked position. it is a recurrent problem and can repeatedly jerk the car to a fast stop when backing up. such quick jerking can make one lose control of the car. *cn
02/05/2010250001
 My 2010 prius stops braking or accelerates when hitting a pothole or bump causing the car to stop later than anticipated. almost hit a person in the cross walk. *cn
01/15/201050001
 My toyota prius 2010 (5000 miles) few times already has an accelerator that goes wild, but luckily for me, i can hit the brakes. it happened only when i drive back from my garage. *jb
02/01/201098001
 Since i bought my 2010 prius i've experienced problems with the brakes. the car experiences a sudden surge of power when going over bumps or hitting potholes if the brakes are being applied at the time. this happens at any speed at any time of day, only when the brakes are being applied lightly. this problem occurs several times a week, always when hitting bumps, potholes or uneven pavement. it always is a sudden, very brief surge of power, sometimes enough to push me back into the seat. so far there have been no consequences other than very frayed nerves. i've reported this to my dealer who responded that the car was a new technology and i simply didn't know how to drive it properly. i learned in subsequent conversations directly with the mechanic that others had complained about this problem but they had no idea what was causing it. to date, the dealer has done nothing about it. the only thing that fixes the problem is to brake further from a stop or to roll over bumps before braking. i'm very concerned about a situation where i need to brake suddenly but the car surges, possibly causing a crash. *tr
07/01/20091
 When breaking my 2010 toyota prius, if i go over a bump or pot hole, it feels like the brakes cut out and my car jolts forwards. it seems to happen only when i go over a bump or something that would shake the car a bit. nothing has been done as of yet to correct the problem. tw*
01/26/20103000
 I have a 2010 prius. when i go over small bumps while breaking, the brakes stop working and the car accelerates for a bit. disconcerting. *cn
08/11/2009251
 After pushing the power button and then shifting out of park to either drive or reverse, the vehicle lunges and i have to apply the brake, which makes the vehicle jerk. sometimes the gasoline engine starts before i shift into gear sometimes it doesn't. this process is repeated over several times for a minute or so, then it corrects itself. i am just inching along lunging, braking, jerking... this has occurred about ten times over the eight weeks and 2540 miles since purchased august ll, 2009. took to dealer, on sept. 29, 2009; they kept it for about 2 hours, could not duplicate and said all systems checked out ok. at that time the problem had occurred about six times. since that date, this continues to happen intermittently. this has happened only when in my own drive or in parking lots. i am fearful that it could happen on the road and cause an accident and injury to myself and/or others. the dealer and toyota case manager say that they must be able to duplicate the problem before anything can be done to correct it. since it happens only on occasion, it will be difficult to duplicate. *tr