Last post on Sep 03, 2013 at 5:22 PM
You are in the Toyota Prius
What is this discussion about?
Toyota Prius, Brakes, Hatchback, Sedan
Go to NHTSA to file a safety complaint.
Or call Monday-Friday (8 am to 8 pm ET) (888) 327-4236 TTY: (800)424-9153
#172 of 370 2005 Prius Sudden brake problem too
Feb 13, 2010 (9:34 am)
Might as well add my two cents worth here. My 2005 Prius (bought new) acts as if I have slammed on the brakes with only a very light touch on occasion. Mostly mornings. This since the very first year I had it. Toyota of Tampa Bay says they know nothing unless they see the problem. Even just an amateur search on the web shows this is fairly common problem. I filled out the little complaint form at the DOT site of "Office of Defects " and I received back a notice saying if I wanted to file a complain .......call this number.That after already filling out a complaint form. LOL. I notified Toyota but they have yet to give me any indication that this is something they are interested in fixing. It's OK though I have kept records and so if we get in a wreck at least my kids can sue everyone involved and maybe get a few bucks out of the criminals.
#173 of 370 Re: 2005 Prius Sudden brake problem too [phydo]
Feb 13, 2010 (2:46 pm)
Do the brakes WORK; i.e, do they stop the car?
#174 of 370 A0B appears to fix problem
Feb 14, 2010 (7:35 am)
I'm still testing but preliminary data indicates A0B fixed the brake pause. I used the following pothole for pre-patch testing:
The pothole, near side, was used for testing: ~4-5 inches deep and 7 feet long. I approached the pothole at ~20 mph since 19 mph is a documented threshold for braking transition. Before the patch, the regenerative indicator showed ~75% but after the pothole it dropped to ~20-15% and there was about a 50% reduction in braking force:
After the patch, the same test scenario showed ~50% regeneration and no reduction in regeneration after the pothole. Accelerometer testing showed no reduction in braking force:
It took a while to realize that the brake pause was not the same as our rain-slick Huntsville streets. I have one more test to run but it will take drizzle wet streets. But based upon the pothole tests run on Saturday, Feb. 13, the patch A0B works.
#175 of 370 Re: 2007 Prius [avucarguy]
Feb 14, 2010 (8:29 am)
I have a 2007 and a 2010. The 2007 has always had this type of issue. Living in NJ I also notice it on snow and ice bumps..especially with the recent snow accumulation.
The 2010 has not engaged the VSC or AB as much as the 2007...but it has happened.
I honestly take this as normal...a Prius may start with a P but it ain't a Porsche.
#176 of 370 Re: Prius Brake Failure/Delay - Dallas, TX [kcbcarmichael]
Feb 14, 2010 (12:48 pm)
Couldn't figure out how to edit my original post, so I just replied to it. I did find that the ABS brakes were working BUT only if I pushed the brake pedal down far enough. On snow and ice, I don't mash them - I have always applied them lightly. Anyway, I still apply lightly, but if I need the ABS to kick in, I'll go ahead and push them down til the ABS kicks in. It does help me stop. My dealer also disabled the beeping in reverse for me. They tried to use the "but how will others know when your backing up" line, but when I responded that I wasn't sure how an internal sound was going to help those outside of the car, they agreed and did it for me.
#177 of 370 Brakes Disengaging, surge, whatever
Feb 14, 2010 (1:52 pm)
I have also experienced the surging (brakes disengaging) in my 2010 Prius II. Like others, it happened as I was braking and ran over some rough spots in the road. It really felt like a surge, but I can see how it was the brakes disengaging. It's happened twice now - I can totally see how someone could rear end someone.
#178 of 370 Re: Prius Brake Failure/Delay - Dallas, TX [kcbcarmichael]
Feb 14, 2010 (2:42 pm)
"..It does help me stop..."
Pushing down harder on the brakes will always help you stop.....EXCEPT if you push so hard or the road is so slippery that ABS activates. There is no condition known to man wherein Anti-lock braking will not extend your stopping distance.
The idea behind ABS is to "reserve" a portion of your front wheels' roadbed traction coefficient for directional control. The bad news is that it will do that regardless of whether you need, or use, that "re-apportioned" lateral traction.
Some day soon I expect that VSC will be used to activate ABS only if it is needed.
#179 of 370 Re: Brakes Disengaging, surge, whatever [kcbcarmichael]
Feb 14, 2010 (3:38 pm)
I have also experienced the surging (brakes disengaging) in my 2010 Prius II............ It really felt like a surge, but I can see how it was the brakes disengaging. It's happened twice now - I can totally see how someone could rear end someone.
That's one of the reasons why it's not good to tailgate.
#180 of 370 Re: Brakes Disengaging, surge, whatever [carnaught]
Feb 14, 2010 (4:58 pm)
Trust me, you don't have to be "tail-gating" in order to rear-end another car, all it takes is a momentary release, TOTALLY UNEXPECTED momentary release, of FULL/PANIC braking.
#181 of 370 Prius Brake Over-ride--Here Now
Feb 15, 2010 (10:38 am)
I had the ABS recall appointment this morning on my 2010 and learned from the dealer's service staff something I must have missed in the 450-page manual and all the media coverage and blogs.
The car does have brake over-ride. It only works at >30mph. Feet on both accelerator and brake pedals simultaneously will stop the car.
I have not experienced any unanticipated acceleration on this car bought in December, but I know the complaint shows up in NHTSA complaints, but not to the degree of cars being recalled for UA. I had already practiced shifting to N and killing the engine by holding the start button for 3 seconds; yes, I know the brakes can overpower any engine surge.
I continue to like this car a lot and have confidence in the company. The bashing from the GM crowd is pretty entertaining, in any case.