NHTSA Tracking Braking Loss on Prius Hybrids

[RobertMBecker]

Article published today in The Detroit Bureau.

[Bobsprius]

I do understand your concern and the article is quite interesting reading.

I do hope that Toyota does investigate the issue and either come to some sort of fix for this issue that you seem to experience on a most often basis.

I don't get your justification for the following, from your article:

"(While he initially was looking for a fix for the problem, Becker now wants a full refund of the purchase price of the vehicle, something the company is unwilling to do thus far.

“It makes me question Toyota’s commitment to customer service and safety,” Becker says

Because there MAY be some sort of issue you want a Full Refund of your Purchase Price???

The correlation is certainly not clear to me. But I hope Toyota will look into this issue since many experience it and either come out with a fix or TSB to resolve it.

[aapoppa]

I've experienced this just one time in 12.000 miles in my Gen III. I don't recall it ever happening in my '05

It'll be interesting to see how this plays out.

[bighouse]

I have felt this loss of braking as well- right in front of my house! There's a rough transition from the aspalt road into my gravel drive and one day, coming home from work, I pulled off the road and pressed on my brakes- and the second I felt the front right tire drop down off the asphalt my brake pedal bottomed out. It went from feeling like a brake pedal to feeling like a clutch pedal! I thought I was going to continue to move forward and take out my mailbox and garbage cans, but I pushed harder and it stopped. Another person might have fared worse and it has caused me to adjust my driving/braking behaviour when on roads that are anything less than smooth and pay particular attention for tracks or potholes!

Toyota really needs to look into this!

[DetPrius]

Interesting timing to see this. I've been thinking that I should file a complaint, though not sure of who to file it with, about this very issue. If I am in an accident someday because of this, I want to be able to say I have already raised the issue. I have experienced it numerous times and it is easy to recreate.

[yardman 49]

Originally Posted by RobertMBecker

Article published today in The Detroit Bureau.

I did a quick search on anti-lock brakes and found the following quotes from an article on brakes published by the "Manitoba Used Car Dealer Association"

"Road hazards that will cause the ABS to function unexpectedly are gravel, sand, ice, snow, mud, railway tracks, potholes, manhole covers, and even road markings when it is raining.

The ABS cannot make up for road conditions or bad judgment. It is still the driver’s responsibility to drive at reasonable speeds for weather and traffic conditions. Always leave a margin of safety."

This article was not written about the Prius, but about anti-lock brakes in general. It actually is a fairly good article, so I'm including the link here:

Anti-Lock Brakes?

As I've posted elsewhere on the forums, I've never had any problems with the brakes on my G2 Prius. In fact, the few times that I've really had to stop quickly, the car stopped so quickly that it took me by surprise. If I hadn't been wearing my seat belt, I would have hit the steeing wheel.

I can't speak for the G3. But I can speak for the many rental cars that I've driven for work over the years. The cars that I've had AB problems with, when traveling over dry but uneven roads, were not Priuses. Most of the time they were Fords, and they gave me quite a scare the first couple of times. But now I know what to expect when driving those models.

[DetPrius]

I never feel the pulsing of the antilock brakes when this problem occurs. It simply feels like a delay between the time regen brakes cut out and friction brakes cut in. It's less than a second but CLEARLY noticeable and WILL wake you up. ABS may be involved but it does not appear to activate as I've activated ABS on ice and know what it feels like.

[brad_rules_man]

It's not just the ABS. It's because the newer model has better regenerative braking and it relies on it a lot. So when your braking heavily and one of the two tires braking slip, it seems like a really big loss before the friction brakes kick in. I've felt it too, and it is jarring. It worries me because it does seem like enough to cause a wreck, but at the same time, I want that awesome regenerative braking. /shrug

[cthindi]

Thps issue definitely exists and I am sure ut is bot ABS kicking in. It has happened atleast 10 times in 18000 Mi I have driven. First time it was scary. Now I am not scared anymore, but the issue is definitely noticeable.

I agree Toyota should most certainly look in to this. I feel it should be more of a software issue.

[bwilson4web]

It sounds as if a small, skid pan is needed to replicate this problem:

1. cardboard-on-cardboard - two cardboard sheets with one on top of the other and brake so one wheel passes over the stacked sheets. Does not require special weather.
2. ice patch - find a frozen puddle and again brake so one tire will pass over the frozen patch. Requires sub-freezing temperature.

Christmas Day promises to be dry and the work parking lot will be empty. Cardboard is in ready supply (or soon will be.) Setup a video record on a tripod and 'do the experiment.'

Bob Wilson