accelerator problems

The issue from the brake recall, perhaps?

 

I have found that Toyota totally stonewalls on this one - I've gone to the dealer multiple times, called Toyota Corporate and even had a regional rep speak to me. "They all do that" or "That's the way ABS works" is the answer. Total BS. File a complaint with the NHTSA https://www-odi.nhtsa.dot.gov/ivoq/ If they get enough complaints, and Toyota hasn't bought them too many lunches, maybe something will finally get done.

 

Since you are so frightened by what happened, run down to the dealership, complain loudly and demand your money back.

What you are experiencing is an issue with the ABS slip control of the vehicle over a rough surface. Read the info that "krelborne" is pointing to.

 

Your getting this from the regen braking noticing slip in the front tires. With regen it uses the drivetrain to slow the car down and charge the battery. Once it notices slip in the front tires it stops regen and applies the 4 wheel disc brakes. Your noticing the short gap betwen this happing. It's not the car going faster it's the loss of the braking froce making you think the car is taking off but its not.

I guess if all you guys complain enough they can remove regen braking and lower the mpg on the window sticker. I hope they don't and even though it has happened to me two times i understand what is going on and feel safe.

Don't take this the wrong way but if there is a really rough bumpy, pothole area of road, you should go slower and be cafefull. Most if not all of cars will kick on the abs in the same situation and cause part if not all of the sensation that the prius gives. No car can get good traction on a crappy road. They will all loose traction and take longer to stop. If you can't understand or deal with this you should sell your car, and not buy another hybrid cause they all do this, Even the ford fusion.

 

That is not what happened. Your car did not accelerate, it merely failed to brake along the continuum that you anticipated. Since it left that continuum, you "felt" that as acceleration, but in fact the car did not gain additional speed.



You felt that the car should have decelerated along the red line as you applied pedal force. When you hit the bump, the brake reset and thereby failed to brake for a second or so, and then continued to brake. Had you left your foot on the brake pedal, it would have continued along the blue line, but eventually stopped without accelerating more. If you removed your foot from the brake to re-apply pressure after you hit the bump, then the flat spot on the blue line would have extended further, but in no case was additional speed gained.



I think what happens is that most people drive without thinking about what the car is doing (and who should?) and so anticipate a "flat" brake force line. If there is a deviation from the brake force line, it is "felt" as acceleration, or a gain in speed, when in fact the car did not accelerate (as in the second graphic.)

So rest assured your car did not accelerate, just failed to brake at the rate you anticipated. Just keep your foot on the brake next time when it happens, if you don't sell your car instead. I have had the brake fix applied before I purchased my car, and there is still a bit of it going on.

 

This is just the car's way of saying, "Hey, wake up & pay attention to me." When you intend to stop on rough pavement or a piece of metal (plate or grate) use a "moderate" or "heavy" pressure on the brake pedal to trigger friction braking sooner. If you are just cornering then light pressure is OK.

You can go to www.toyota.com/owners to see if your car is subject to the Brake ECU reflash.

 

The same thing happened to me the first day I had the vehicle. It was a little unsettling and did feel like acceleration but obviously wasn't, just loss of braking for a split second. I learned to go a little slower coming to a stop.

 

About how fast were you moving when this struck? About how hard was the braking -- hard, medium, soft, very soft?

 

this is another genIII problem that is barely noticeable on the genII.

 

No, not all hybrids do this .......

only those based on Toyota's HSD design.

 

And also Toyota non-hybrids. The FJ Cruiser does this.

Tom

 

My '09 does this sometimes, too...but I know that Adamace1,
mmcdonal and JimN are correct in all respects.... Just know the
car does this every once in a while with rough roads...esp. after winter and there are pot holes. But there's nothing wrong with the car and nothing to be alarmed about, just be AWARE.

 

And the 2000-2002 GM trucks

 

For anyone who may have some doubt and wants to show themselves that your brain can make you think the car is speeding up while slowing down...

If you shift into neutral at some point while at speed with the engine off (with no one around), then press on the accelerator for several seconds, when you take your foot off the accelerator (all still in neutral), you will feel as though the car just accelerated at the moment of pedal release. Of course it did not at all, but our brains expect a certain sensation with certain input, and when the car continues at the same speed, or even lightly decelerates provided you're not going downhill, you're fooled into thinking the car just went faster without your control.

 

Sorry but it is a fact other hybrids do this too. Ford Had the same "service compain" Toyota did with their prius it included all Ford fusions Hybrids. They were getting alot of complaints too and did the same thing toyota did, tried to make it better with a software update. I don't have time to show you all hybrids has this problem but i will back up my claim about the ford fusion.

http://www.hybridcars.com/safety/ford-admits-hybrid-braking-problem-26594.html

 

Yep, mine did.

 

Another test to give you the sensation of loss of deceleration that feels like acceleration:

When it is safe to do so and while braking to a stop at around 45 mph, shift to neutral. You will feel the transition from regenerative braking to friction braking. On my car, there is a definite loss of deceleration when this happens, albeit small, and I have to increase the pedal pressure to get back to the same deceleration rate as before.

I understand that doing this under controlled circumstances is not the same as when this happens unexpectedly, and not as pronounced as when you hit a rough or slick spot, but it will give you the sensation of acceleration so you will at least know what to expect if it happens again.

 

Yep, it happens. But so long as you are looking at the road (hopefully that's all of us) you'll see the potholes and know it's coming. I have one on the way home from work, and if you either brake very lightly or very hard over it nothing happens. it's just a middle ground of braking where you'll feel the switch.

It's not great, but it does -not- affect the cars ability to stop. if you have that pedal on the floor when you hit the bump it mkaes no difference.

 

If you decelerate before the pothole, or before that 90 degree corner and then keep your foot OFF both the gas pedal and the brake pedal, you will find that the cars stability is perfect. I often try to slide the car and cannot. When the traffic situation is right I often take the turn at 15-20 MPH. Just the act of turning also slows the car down dramatically. I suppose it has something to do with vector forces and momentum. As for imaginary acceleration I have never experienced it. Method of driving may be a big determining factor. I have observed drivers going 3 blocks and hitting the brake pedal 10 times, WHY? :cheer2: