Car 'slips' when braking.

We will have to agree to disagree.

You should not feel "slippage" when ABS is activated on dry pavement even if it is uneven. Remember, the sole function of ABS is to maintain maximum breaking power at all times independently on each wheel up to the the point a wheel would begin to lock. On a properly operating system if one wheel lost traction while braking, say by running over a wet manhole cover, the other three wheels will continue to have full braking power. The temporary lose of braking on one wheel only should not be felt inside the car as "slippage".

 

Take a service rep with you and show them. I experienced the same before the fix (but could not reproduce at will). My understanding is that the duration of the slip is reduced from about 0.8 sec towards 0.2 sec by the fix.

 

If braking with regen only, there will be complete loss of braking as soon as either front wheel loses traction. There used to be a time gap after this happened and before the friction brakes kicked in. I believe the fix shortened this gap.

 

I had mine fixed or they said they did. Before the fix and after the fix mine still does it. Toyota is a BS artist and they are getting away with it. There is no fix and all the new Prius's have the issue. It's a Fu&&&k up from Toyota and that's it, period.
So what are we going to do about it??

 

i have heard several folks talk about not getting the correct software install. this is a dealer issue, not a corporate Toyota issue. if you think you still have the problem, take it to a different dealer. explain to them your concern. it is not a difficult process for them to plug in your car and check the software, or even reinstall it for your piece of mind. i got mine after the software update, so i have no comparison. but, i do have a bumpy offramp that i have checked to see the brakes react on, and it is perfectly normal, and exactly what i would expect from the brakes. same as every other car we have.
take it to a different dealer. get it verified. relax and enjoy the ride.

 

For what it's worth, I have the recall version of the 2010. Took it in last Saturday, they told me 45 minutes to reset and it took 20. I've driven over the same bumps that caused the problem before and so far (can you hear me knocking on wood?) no problem. The service guy did say this problem occurs with most Anti Lock Braking Systems.

 

My car before and after the fix never ever experience any of the braking issues mentioned. My guess is that you just will have to bring your car back into the dealer, or better yet another dealer, and ask them to reverify that your car's ABS ECU was flashed properly.

 

And that is unacceptable. The system wasn't ready for prime time.

 

90% of any systems aren't ready for primetime. almost every first year model of anything has bugs. it is impossible to work out all the bugs without a mass of real world use.

 

loss of traction = loss of braking.

You can't change physics.

 

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Agreed but a partial loss of traction should not result in a total loss of braking.

 

I tend to agree all cars do this to some extend. Been driving BMW 3 and 5 series for over ten years. Just that bimmer suspension is so much better that the car barely moves over a bump while the Prius flies in comparison. And when that happens, you get a lot more flying sensation in a Prius. Am I worry? Not really. But I understand how people would be concerned. I have a good bump near my house where I can reproduce this every single time. Have not done my recall yet, so it would be interesting to compare before and after. Can't wait till my 5k oil change to get that done. ;-)

 

The problem I have with the endless fixation on this "issue," is that it draws attention away from what may be a real and present danger: the reliance (in ALL modern cars) on electronic throttle control (fly-by-wire) systems without adequate fail safe mechanical over-ride.
In itself, this issue (ABS) is more like a "quirk" (my wife's term) than a serious safety concern.
Unintended acceleration is something else.
IF it is caused by computer malfunction, fail-safe devices NEED to be developed to over-ride the computer if it locks-up or fails.
The back-up needs to be something other than another software command, or even another microchip.
Some kind of hardware emergency stop device that doesn't need electricity to function needs to be developed and applied.
Meantime, we practice putting it in neutral and pushing the button for 3 seconds--just in case.
And we realize that trading the Toyota for a Chevy or Ford won't reduce the risk...

 

My 2010 Gen III also slips and sometimes seems to have some acceleration especially when going over a bump on a wet road. I wanted to point out here is that the Gen III has ABS (Anti-lock Brake System), Brake Assist, Enhanced VSC (Vehicle Stability Contol) and TRAC (Traction Control). The vehicle also has both regen braking and hydraulic braking which transitions at low speeds. The Gen III Prius is constantly being managed by automated systems. There is the human input on the brake and accelerator pedals, the input of the sensors for the automated systems and the mechanical/electrical system trying to extract the maximum mileage from the fuel. The automated systems must constantly manage all the sensor inputs and human inputs and decide how to control the car. Slip or unweighting one wheel during braking or acceleration in a slippery environment has to be a challenge for the control systems. I have about 11K miles on my Gen III and feel secure when driving. The small slip or acceleration in certain circumstances has not eliminated the overall feeling of a safe car. I remember getting used to my first ABS on a Volvo many years ago. The first time the ABS kicked in I was really scared. I realize that the issues we are discussing with the Gen III may seem a little more worrisome but overall I am willing to live with what I consider to be minor problems in order to get the benefit of ABS, Brake Assist, VSC, TRAC and regen braking.