braking in reverse

I really do hope the recall will fix this otherwise nice car. I had folks in the car with me when this "grabbing" started again. Needles to say they thought I was joking. Really guys if the dealer or Toyota is not listening, a formal complaint should be filed. It is way to many complaining about this but not doing enough to force them to fix it.

 

There's too many pages here for me to read all of it, so maybe someone who's been following the thread can smack me if this has already been brought up.

I've had sticky brakes twice (in reverse on mostly level ground). Both times, I was sitting in the car for a bit before turning it on. I don't remember if it happened the last time, but this morning, I also noticed that the pedal was a lot lower than usual (sank lower when I stepped on it to start). My guess is that it has something to do with the accumulator.

When you open the door, it pumps up the brakes. If you let it sit long enough, it probably loses pressure. Now that the pedal is lower, the computer thinks that you're trying to brake harder. I don't recall if the pedal was "firmer", but it was definitely more sensitive.

 

The pedal is not lower in my car. The pedal travel is greatly reduced during the episodes and then goes back to normal travel when the episode ends. See video:

[ame=http://www.vimeo.com/9170569]Strange Brake Issue on 2010 Prius on Vimeo[/ame]

 

Hi Gary,
Thank you so much for this post, it is hugely helpful, because the exact same thing happened to me twice last week. Now I know I am far from alone. Can't believe how many of us out there are experiencing this problem. I wanted to ask if anyone at Toyota has diagnosed or fixed the problem for you yet? I am really shaken by all of this, have little faith in Toyota at this point (after being a fan for 25 years) and don't feel safe in the car.

Here's my notes I've typed up so far, just to document all the insanity with Toyota, should I need to return the car :

I just bought my 2010 Prius on 1/25/10. On 2/2/05, I was leaving a parking space after the car had been off/sitting for about 10 minutes (no passenger). The weather was mild (65-ish) and dry and the ground was level and pothole-free. I turned the car on, waited til "ready" lit up, put it in reverse and began to ease off the brakes with the intention of slowly backing out of the parking space. As soon as I started to ease off the brake, the car shot backward at an alarming speed (my foot was still partially on the brake and it should have been going very slowly). When I pressed the brakes to stop the momentum, they jerked very hard and slammed on unnaturally. I had to do this about 4 or 5 times--start to release the pedal/unintentionally shoot back/get jerked by the brakes, to get out of the spot. Had a car or person been close behind, they would have been hit. After I put it in drive and drove off, the problem went away.
On 2/5/10, the same exact thing happened. Conditions were identical--level ground, backing up after just starting the car and same jolting back/jerking forward response of the car. The only difference is this day, it was raining and the car had been sitting for approx 1.5 hours. Again, it was very scary and thank God, no one was walking behind.
I called the dealership to report the issue on 2/3/10--we phone tagged and spoke in person on 2/4/10. I opened a report with Toyota (800-331-4331) on 2/5/10. I told the service manager I did not feel safe driving the car and wanted it looked at ASAP. He kindly offered a rental on 2/6/10, but we were able to use my husband’s car over the weekend. On Monday 2/8/10, the service mngr. came to my house and rode with me to the dealership. The problem did not present itself at that time. We test drove another 2010 Prius, with the same package as mine (IV) and again, the problem did not replicate. I left my car with him and was given a rental. On 2/8/10 the 2010 Prius recall became official, but for a different braking issue. On the evening of 2/10/10 the dealership called and said my car had received the recall software update and was otherwise ready for pickup. I was dumbfounded and asked what had been done to fix my specific brake problem and he said the car checked out fine, and that the computer showed the gas and brake were applied simultaneously, so I must have done that myself to cause the incidents! I found this not only wildly implausible, but deeply insulting!! I was steaming mad and utterly speechless. I have been driving for 23 years, have a perfect driving record and certainly have never applied the brake and gas at the same time! If the computer is saying that, it’s either wrong, or the car has a defect and is applying the accelerator on its own in this circumstance.

Next, I googled, “2010 Prius brake problems in reverse” and found this fantastic forum. I let the dealership know there are hundreds of other Gen 3 owners out there with the identical problem and clearly, we are not all driving around with our feet on the gas and brakes! At this point, I told them I will not pickup the car unless the problem is properly diagnosed and fixed, otherwise, and I hate to say this because I love the car...I'd have to seriously consider returning it.

Just curious if anyone out there has actually been able to pinpoint and fix this issue. And do you feel your Gen 3's are otherwise safe?

Thanks so much,
Nettie

 

I've had this happen once while braking in reverse after sitting in the car in ACC mode for 5-10 min. It wasn't worse than my previous car which would sometimes activate ABS in a rattling noise when smoothly braking in reverse.

I'm 100% sure that this is a minor pb and that the car is perfectly safe, despite all the media non-sense going on right now.

 

The number you provided is a scam!!!! DO NOT CALL THAT NUMBER!

Google that number if you don't believe me. You will be charged for calling it.

The real toyota number is: 1-800-331-4331

I will give you the benefit of the doubt that you are not here to spread this scam. I too would like to fix this brake sticking issue.

 

Oh jeez, that was 100% a typo on my part, I am so sorry!!! The # I called was indeed 800-331-4331. I waited on hold over an hour and then had a nice guy help me open my case.

 

Re: braking in reverse UPDATE

Hi Everyone,
Just an update on the reverse braking/acceleration issue. I picked up the car at the dealer today and spoke at length with the Parts and Service Director. He told me he had just had a conference call with Toyota last night that shed some light on things. In a nutshell, even though the recall is technically about the braking reaction on icy/bumpy roads, he said that the software update should also fix my problem. The update is toning down aggressive programming that was causing the gas and electric systems to shift roughly between one another. Also the RPM's were set too high. The two times I had the reverse incidences, the car very clearly clunked between modes as it was shooting back/jerking forward. While I wasn't completely convinced by his assurances, it did make logical sense to me. I agreed to try the car for a few days and see how it felt. I drove a few miles around town and it felt fine--though the acceleration from a stopped position did seem more sluggish and the brakes a bit more sensitive. I ran a few errands, backing up a few times with no problem. Then, about 5:15pm today. I got in the car (after is had been sitting no more than 10 minutes), pressed the brake and pushed power. I knew before I even put it into reverse, the jerking backup was about to occur--the brake felt totally different and extremely stiff. I eased off the brake and lo and behold--it happened again. This time, thanks to all of you, I knew to put it in park, turn it off and then on. After that it was fine. I will say that the incident was much milder than my other two, so the new programming definitely seemed to help. I called the dealership and filled them in and at this point, I'm just gonna drive the car for a few more days and see if it settles in or if problems persist.
Just wanted to update you all in case it helps.

Nettie

 

Re: braking in reverse UPDATE

My first post! This thread has been really helpful to me although I am not very impressed with my dealer.
I had a reverse braking incident. My driveway has a downhill incline. A couple of weeks ago, as I was backing out of the drive, I noticed that I was getting too close to my trash bin and didn't want to hit my drivers' door mirror. I pushed on the brake and the car accelerated backward before the brakes suddenly grabbed. Bad news is that my mirror snapped during the accelaration. I had only experienced this weird back up jerkiness 1 previous time in my 1800 miles on the Prius.
I bought a new mirror and it was $320 for part and labor at dealer. When I went to pay, the guy in the service department said I was the 3rd person in a week to have a mirror replacement in 2010 Prius due to backing into something.
After the fact, I found this Prius Chat about the reverse braking issue. By chance, the dealer had a new owner welcome event last week. I attended and brought up the info I had seen on this site about the reverse braking issue. The dealership told me that they had never heard a peep about this issue until I mentioned it.
Anyway, I like but don't love my Prius. I'm averaging 37 mpg for the 1800 miles driven-- a lot less than I was expecting. I haven't received any notification yet about the recall. Dealership scheduled me for a 3000 mile oil change "just to keep an eye on it." Now I understand there is a 10000 interval. Dealer says they will never recommend more than 5000 miles bteween oil changes because Eastern Washington is dusty.
Anyway, I have found this site helpful. Thank you.

 

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I to have this problem. It has happen many times. I had the brake recall done and hoped it would fix it. I stopped at the dealership yesterday, went into the parts department and made a purchase. When I went out to the car I put my foot on the brake and started the car, I felt the brake pedal become very hard and the backup problem happen again. Please get a fix for this before someone is run over when I back up or I crash another car. Does someone have to be killed to get a recall?

 

Generally yes.

Tom

 

Umm, how do you run over someone or crash another car if the grabby brake syndrome makes it difficult to get the car moving?

 

I've seen one complaint of this a lady said it had done it like two times with her.
Drove the car but did not feel it. For the ones that have had this happen and then had had the SSC AOB done see if it still does it? I'm thinking it may affect it or get rid of it.

 

I noticed this problem again the other day after a car wash complete with someone wiping down the windows from the interior. He left the doors open for a good 10 minutes without starting the car, for those collecting data points about potential triggers. I've also been suspicious that putting the car into gear before the start-up transient is complete (i.e., yellow triangle is gone on the HUD) could be related, but I haven't taken the time to test for repeatability yet.

 

That definitely isn't the cause. Every time I had the problem it was after the car was sitting for an extended period (several minutes) with the ignition on listening to the radio and then backing out of the parking space. It doesn't happen every time I did that, but it only happened under those settings and has never happened right after I started the car up and immediately backed out.

 

I've never read this thread before tonight. Earlier today, this happened to me. I have 5,000 miles on the car so it was pretty jarring. Anyway, all I did was press park, shift back to reverse, and problem solved.

 

It is the abrupt, substantial, unexpected acceleration (just after first starting and easing up on the brake pedal) that is the danger, not the "grabby" brakes trying to stop it.

 

I now have about 7,500 miles on the car. I thought the problem stopped after 5,000 miles, but it occurred again yesterday. It seems to happen when the car isn't warmed up, although more often then not, I put it in reverse right away and there's no problem. When it happens, I stop, put it in park, wait a little, then it's OK.

 

I made this post(s) on "grabbing brakes in reverse" in July and it has continued unpredictably 2-3 times a week since then. I read and tried some of the tips other members made, all w/o success. I made several trips to my dealer in Santa Monica, who took my complaint very seriously, but couldn't duplicate my problem. Eventually, I wrote and talked with Toyota in Torrance, CA and they decided to send one of their Quality Control people out to check out my complaint. As I expected, he was unable to duplicate my problem, but said that he thought the new ABS software update change would probably solve my problem. He was right.

Two weeks ago, they put in the ABS change and my problem was completely solved. I have not once experienced any grabbing. To reiterate, they took my problem seriously, even though it was not the same as the majority Prius owners in the US were experiencing.

My recommendation is that all owners of the 2010 models have the new ABS software upgrade installed as soon as possible. I believe Toyota has had an unfortunate bad run of problems lately, but I truly believe they have been both professional and diligent in trying to resolve them.

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