Braking Under Heavy Snow.

[Sico2]

In the recent winter break out I noticed a puzzling thing about my Yaris' brakes that I forgot to mention. It only came up to me today after reading an article about Prius' brakes problem in USA.

I went out for a spin (to Tesco's :P) in a really bad weather condition (snow, mud, -°C temperatures etc.) as I love to drive in snow. As I approached a crossing with red light I started to brake gently. I know ABS prevents the wheels from blocking on slippery surface, but as I started to push harder on the pedal to slow the car down a bit harder a very strange thing started to happen.

As I've never driven an ABS equipped car before I'm wondering if it's normal. Mainly, the pedal backed off my foot a bit, lost it's braking feeling completely(very soft, loose with no pressure under it) and started to rattle. It was a quite loud, sharp, numb plastic-y noise. As if you were rubbing with force with something over a plastic gear (like a pullback toy cars you play with and you pull them too much). You could hear some mechanism being overdriven, overrun or something not really right. It's hard to describe.

I noticed that at this moment the wheel most probably started to slide over the surface as I were loosing control over the car and that was what caused the ABS to go bonkers.

I let the pressure off the pedal, and started to push on it back again, but a bit more gentle. The braking feeling came back with proper braking until you pushed it in again. It happened at only icy road, never again.

Anyone knows if I should be worried about that?

[Madasafish]

Anyone knows if I should be worried about that?

Sounds normal ABS behaviour to me.

[Raeman]

Sounds like normal ABS behaviour to me aswell. I hate the ABS in my Yaris, it just feels like i have no control compared to older cars without ABS when driving on icy roads.

But then again, i hate the snow & ice more than the ABS!

[Shappers]

sounds just like the ABS kicking in. Gives a very odd sensation through the brake pedal.

I do find the ABS in the yaris is very sensitive, seems to come on at the drop of a hat.

[Vitz_man]

Esentially what is happening there is the ABS is controlling your brake pedal to stop the brakes locking, which is the vibration you feel when you use it. You can try using it on a completely dry road in nice sunny conditions by braking as hard as possible at about 40mph (make sure there's nothing behind you) and you should feel the same thing. Its weird when it first happens but at least you know what to expect next time. Nothing out of the ordinary with what you experienced as far as im aware. And I also like it how im not the only person who loves driving in snow! :P

Since my car doesn't have ABS I couldn't comment on Toyota's ABS system, but I learned to drive in an 09 plate mini which did the same thing when I was doing emergency stops and when I was dicking about in the snow in a loan car from mini while my dads Cooper S gets fixed. (Apparently they don't know whats wrong with it, and its 3 weeks old! :S) Primarily its designed to stop you locking under heavy braking on roads where conditions are not prime, allowing you to steer to avoid accidents or whatever, but we all know snow and ice are a little bit different! :P

[Sico2]

Thanks guys for all your answers.

So according to Toyota, disabling braking possibility, while you actually need it the most, is normal... weird policy they have.

[Sagitar]

Thanks guys for all your answers.

So according to Toyota, disabling braking possibility, while you actually need it the most, is normal... weird policy they have.

There is no way that abs disables brakes. It makes it possible to keep the car under control while braking hard - especially on slippery surfaces.

Have a look at this video.

[Cyker]

Yeah, the idea is to maintain braking force but preventing the wheel from locking.

A good ABS system would allow you to steer even while driving the brake pedal practically through the floor; In a non-ABS system, that would lock up your car's wheels and no amount of steering would change your course - You're just a passenger after that

The Yaris' ABS works okay when there's grip, but it's not great on ice as I found out not that long ago

Certainly wouldn't be able to replicate what Tiff does in that video!