Anti Skid ops

[jamesbalch]

Hello people!

Have been a Prius owner for all of 7 weeks or so. Has anyone had the anti skid operate in a somewhat violent manner?

I was proceeding downhill on a wet roadway...no leaves or debris in road...doing about 25-30 MPH. Approaching a stop sign, I began to gently apply brakes and for about two seconds, thought the car was going to come apart! Bright orange annuciator under "ready" light (antiskid) illuminated briefly and car shook violently.

A week after I had bought the car, I was in a traffic situation where I had to apply heavy brake pressure on a wet roadway and did see (and feel) the anti-skid operate....but NOTHING like this last time!

Just curious - thanks for any reply. :P

[Tideland Prius]

Keep in mind that traction control is different from stability control even though they use the same light. The "slip" indicator comes on when traction control is activated. If you see the light AND hear a beep, then it's the stability control. Chances are, you activated traction control and thus ABS as well.

[Pinto Girl]

I hate to admit it, but I get this weird sense of accomplishment every time I take a corner really fast and the little "skidding car" light comes on...

...but that's just me.
[smile]

[chogan]

[quote=Jim B. @ Oct 29 2006, 12:48 PM) [snapback]340317[/snapback]</div>

Hello people!

Have been a Prius owner for all of 7 weeks or so. Has anyone had the anti skid operate in a somewhat violent manner?

I was proceeding downhill on a wet roadway...no leaves or debris in road...doing about 25-30 MPH. Approaching a stop sign, I began to gently apply brakes and for about two seconds, thought the car was going to come apart! Bright orange annuciator under "ready" light (antiskid) illuminated briefly and car shook violently.

A week after I had bought the car, I was in a traffic situation where I had to apply heavy brake pressure on a wet roadway and did see (and feel) the anti-skid operate....but NOTHING like this last time!

Just curious - thanks for any reply. :P
[/b]

Several people in several threads on this board have mentioned variations on your situation, where the key element is "I was braking while going downhill." For me, if I hit (say) a small pothole while braking downhill, the car will totally disengage the brakes for a split second and thereby scare the poo out of me. You are the first one to have mentioned violent shaking that I've seen, though I can believe the ABS might (properly) do that under the right circumstances.

Having seen a lot of people (including experienced Prius drivers) mention issues with having the stability control or ABS cut in in odd, undesirable ways while braking downhill, I'd be likely to attribute this to a generic shortcoming of the design, not to anything particularly wrong with your car.

Several people here have mentioned training themselves to live with it, and I guess I now fall in that category. I actively dodge small potholes when braking.

On the other hand, I keep finding new situations that I have to be careful around. Last week I nearly rear-ended a parked car when trying to pull off the pavement and onto the nice, smooth, dry gravel/grass shoulder. Didn't give it a second thought -- it was not at all a dangerous situation. Or, at least, would not have been dangerous in any other car I've driven. But when the wheels went onto the shoulder, the car disengaged the brakes. Again, just for a second. Luckily I tend to drive conservatively and was going pretty slowly at the time. No damage done except to my heart rate.

So, what I think I learned is that I can't trust the car's handling on anything but smooth pavement. Which is OK -- that's what I drive it on. I just have to be cautious in all other situations. It's a pity because it's not a problem with the suspension or brakes, just with the electronic controls.

And I'm willing to believe that hey, this is what the car does, and it's my attitude that needs adjustment, not the car. Obviously, this can't actually be too dangerous or we'd have heard about it by now, more than just the occasional anecdote. I'm just having a hard time adjusting to it.

Other contributors here have said that, in the event of such a braking loss, you can get the brakes back by, in effect, mashing the brake pedal to the floor. Or, as with a traditional car, letting up and applying the gas for a second. Either because I'm too old (learned to drive before ABS) or whatever, I've never had the wit or reaction time to try mashing my foot to the floor, and, while I have the sense to let off the brakes in a regular, old-fashioned skid, as I was trained to do, the stability/ABS brake cutout just doesn't seem to trigger that reflex in me. It's not a skid, its a loss of braking. By the time I've said "what the]#$#@?", it's too late for me to do much anyway.

So I tend to view the stability/ABS/traction control systems as an inherent design flaw, and try to drive in such a way that I never trigger them. At this point, I think I've found all the situations on my normal routes that will set them off, but you never can tell.

[SomervillePrius]

If you brake lightly (i.e regen braking) and hit a pot hole so that a wheel locks-up (and you get that orange warning light) and the prius will disengage the regen braking and apply friciton brakes instead. For a split instance you can feel the brakes disengage (which is a hart stopping moment) as the prius switches from one system to another. The prius will not engage the regen brakes again until you let go of the brake pedal.

As for the violent shaking, I've never felt that! You sure the road didn't have a lot of pot holes in it?

[jamesbalch]

<div class='quotetop'>QUOTE(SomervillePrius @ Nov 1 2006, 10:47 AM) [snapback]341886[/snapback]</div>

If you brake lightly (i.e regen braking) and hit a pot hole so that a wheel locks-up (and you get that orange warning light) and the prius will disengage the regen braking and apply friciton brakes instead. For a split instance you can feel the brakes disengage (which is a hart stopping moment) as the prius switches from one system to another. The prius will not engage the regen brakes again until you let go of the brake pedal.

As for the violent shaking, I've never felt that! You sure the road didn't have a lot of pot holes in it?
[/b]

Negative on the pot holes - smooth roadway. But thanks for the info!

[eagle33199]

<div class='quotetop'>QUOTE(Pinto Girl @ Oct 31 2006, 04:40 PM) [snapback]341585[/snapback]</div>

I hate to admit it, but I get this weird sense of accomplishment every time I take a corner really fast and the little "skidding car" light comes on...

...but that's just me.
[smile]
[/b]

Same here... especially on this one turn on my commute to work - there's the tiniest of pot holes there, so you're guaranteed to engage the light.

[hyb07]

Hello,

Normally the traction control will not kick in above 20mph, atleast thats what on my Odyssey 02 van. But it do send a wave of shudder thruout the van from front to back, I guess that comes from the breaks being activated and deactivated on all the 4 wheels.

Iam just new to Prius like you still on the first tank of gas and thanks for the caution. Its alway better to be perpated than surprised.

happy hybrid driving.

hyb07