Traction Or Stability Control?

[phil4]

I'm pretty sure I saw in the marketing material that the new prius has traction and stability control, think they called it VSC+ or similar.

Having driven on icey carparks and the like over the past couple of weeks, one thing I've noticed is a definate lack of either of the above, the car will understeer wildly on ice when going too fast, and spin up the wheels when accelerating. No lights lit, no beeps, just loss of control.

Yes, I can drive slower, used to have an MR2 roadster, much more prone to spinning, and no VSC or similar.

Is this another item that is mentioned but not present (eg. dual zone aircon)? Is it not very good? Perhaps it just lets you get a long way out before it dips in?

[ian rooke]

hi both my Gen 2 and Gen 3 would react when one wheel went over a wet manhole cover when accelerating the warning light on the dash would also come on

[reece]

Do you have the pre check lights come on when the ignition is turned on? You should see ‘VSC’ and a symbol of a car sliding?

[timberwolf]

hi both my Gen 2 and Gen 3 would react when one wheel went over a wet manhole cover when accelerating the warning light on the dash would also come on

Following on from that, if you lose grip to all four wheels at the same time, then (If I recall correctly) the skid ECU doesn't know that there is a problem as it compares the wheels against each other.

Yes, the traction control was made less aggressive on the Gen 3, possibly because some owners complained - perhaps a case of be careful what you wish for?

[reece]

if you lose grip to all four wheels at the same time, then (If I recall correctly) the skid ECU doesn't know that there is a problem as it compares the wheels against each other.

Incorrect. The yaw sensors, wheel sensors steering wheel sensors and speed sensors will pick that up before you even realise that you are going sideways and keep you in a straight line. Try it

[timberwolf]

Incorrect. The yaw sensors, wheel sensors steering wheel sensors and speed sensors will pick that up before you even realise that you are going sideways and keep you in a straight line. Try it

I take your point about the other sensors. Although, if all four wheels have lost grip, how is any system that operates through the tyres and requires some friction, going to keep the car in a straight line?

[reece]

Incorrect. The yaw sensors, wheel sensors steering wheel sensors and speed sensors will pick that up before you even realise that you are going sideways and keep you in a straight line. Try it

I take your point about the other sensors. Although, if all four wheels have lost grip, how is any system that operates through the tyres and requires some friction, going to keep the car in a straight line?

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[Sagitar]

I'm pretty sure I saw in the marketing material that the new prius has traction and stability control, think they called it VSC+ or similar.

Having driven on icey carparks and the like over the past couple of weeks, one thing I've noticed is a definate lack of either of the above, the car will understeer wildly on ice when going too fast, and spin up the wheels when accelerating. No lights lit, no beeps, just loss of control.

Yes, I can drive slower, used to have an MR2 roadster, much more prone to spinning, and no VSC or similar.

Is this another item that is mentioned but not present (eg. dual zone aircon)? Is it not very good? Perhaps it just lets you get a long way out before it dips in?

The VSC+ indicator lights up when I first switch on the car (just above and to the right of the seat belt indicator on the right hand side of the display) and the behaviour of the car on snow and ice in the last two weeks has been exemplary. However, I do try to drive it in a way that gives it the best chance.

If you are spinning up the wheels when accelerating perhaps you are giving it too much wellie? And if it understeers wildly on ice when going too fast, doesn't that make you ask why you are going too fast? Modern systems can help, but they can't obviate the laws of physics.

Earlier versions of traction control could bring a car to a complete halt by reducing power when there was reduced traction, even to the point of stalling the engine and would give you no chance of re-starting. More recent systems will allow the wheels to spin in a limited way, so that you have a chance of moving, but they do require sensible use of the accelerator.

[phil4]

The VSC+ indicator lights up when I first switch on the car (just above and to the right of the seat belt indicator on the right hand side of the display) and the behaviour of the car on snow and ice in the last two weeks has been exemplary. However, I do try to drive it in a way that gives it the best chance.

Yep, think I know what you mean, beleive this also blinks when you use the hill-start approach.

If you are spinning up the wheels when accelerating perhaps you are giving it too much wellie? And if it understeers wildly on ice when going too fast, doesn't that make you ask why you are going too fast? Modern systems can help, but they can't obviate the laws of physics.

Completely agree, far too fast or brutal. However, I've always wanted to know how the car I drive reacts "on the edge", hence an icey carpark rather than a road. I really don't want a nasty surprise, right when I'm in the middle of another. In this case, was expecting something to cut in/out, but it didn't.... or certainly wasn't noticeable.

Perhaps as you suggest, the laws of physics can't be overcome (I remember a phrase to that effect in the last car's manual), and so understeer continued as there was nothing more the car could do.

Earlier versions of traction control could bring a car to a complete halt by reducing power when there was reduced traction, even to the point of stalling the engine and would give you no chance of re-starting. More recent systems will allow the wheels to spin in a limited way, so that you have a chance of moving, but they do require sensible use of the accelerator.

And there perhaps is the answer, too subtle for me to notice, though as mentioned, expected the VSC+ to light up, but didn't.

More testing required I'd think.

[connoleg]

My VSC+ has been going like the clappers throughout the recent weather. So it appears that its working for me at least. As to whether its any good?, I haven't hit anything (yet!)

'59 T4Spirt