Avensis Vsc Sensitivity

[frape]

HI,

I have the latest avensis 2.0 petrol sedan and have a question related with VSC. According to Toyota and their mobile electronics testers, my VSC works fine. In fact, if I drive (actually spin) the car AGGRESIVELY in an empty parking the VSC is activating (I hear the beeps). However, when I drive the car in real situations, it never activates. I have (by mistake) understeered and oversteered 2-3 times and VSC (and TRC) did not activate. Of' course in these real situations, the car oversteered or understeered less that 1 meter (a few hundreds milliseconds) but my feeling was that VSC (or TRC) should have activated, since nobody knowns before hand how much time it will take for the car to regain its grip.

Please let me know your experiences with VSC. How sensitive is your cars' VSC (in good road conditions)? What I am interested to know is whether VSC activates AFTER the car has slipped or before the car has slipped. Toyota told me that they could test drive the car only at GREECE's master technical repair site which is too far from my residence. Thus, I want to be 100% sure that VSC is not working properly before spending a day to go the repair site.

Thank you for your feedback and help.

Frank

[uumode]

I've never known VSC to activate

Traction control activates easily enough for me, usually on very hard acceleration out of a junction with front wheels turned.

Though I find the way the traction control operates a bit abrupt, it nearly totally cuts the power to the engine (or the wheels) and is not that progressive in cutting the power, it's either all power or no power, which is a bit annoying when trying to exit a junction very quickly as there is a car coming!! The delay suffered by the traction control cutting in is probably about the same as having the wheels spin on you

[D4Ddriver]

Vsc seems very senitive on my 2004 d4d 2.0 avensis on a roundabout in wet slippy conditions the beep sounds and the car recovers from oversteer with fast responce almost instant correction the back end had just started to move I found that I could play with the rear oversteer and get the car to beep at every wet roundabout. Not trying too hard either. 17 inch alloys with budget tyres on the back 30psi.

maybe you could up the tyre pressures a bit to test it.

good luck

[frape]

HI,

I have the latest avensis 2.0 petrol sedan and have a question related with VSC. According to Toyota and their mobile electronics testers, my VSC works fine. In fact, if I drive (actually spin) the car AGGRESIVELY in an empty parking the VSC is activating (I hear the beeps). However, when I drive the car in real situations, it never activates. I have (by mistake) understeered and oversteered 2-3 times and VSC (and TRC) did not activate. Of' course in these real situations, the car oversteered or understeered less that 1 meter (a few hundreds milliseconds) but my feeling was that VSC (or TRC) should have activated, since nobody knowns before hand how much time it will take for the car to regain its grip.

Please let me know your experiences with VSC. How sensitive is your cars' VSC (in good road conditions)? What I am interested to know is whether VSC activates AFTER the car has slipped or before the car has slipped. Toyota told me that they could test drive the car only at GREECE's master technical repair site which is too far from my residence. Thus, I want to be 100% sure that VSC is not working properly before spending a day to go the repair site.

Thank you for your feedback and help.

Frank

Any other opinion? How instance, how much sensitive is your VSC on dry road? Does VSC activates immediately the car slips or is there a time lag?

[Parts-King]

The main reason for VSC is to stop you losing control under heavy braking while trying to change lanes and back again, rather like the traffic stopping in front of you on a motorway, you braking too late and having to swerve from one lane to another and back again. it works with a yaw sensor dectecting how much slip there is at each wheel and controling the brakes via the ABS. along with reduced engine power, So, you may have little "slip" at each wheel in the dry, but much more in the wet, so you can never say, "it always works like this" because no two situations are the same. A quick explaination can be found here

A very complicated piece of kit we take for granted, I tested it on a race circuit in Spain under controlled conditions, it was fantastic on the Auris. Kingo

[frape]

The main reason for VSC is to stop you losing control under heavy braking while trying to change lanes and back again, rather like the traffic stopping in front of you on a motorway, you braking too late and having to swerve from one lane to another and back again. it works with a yaw sensor dectecting how much slip there is at each wheel and controling the brakes via the ABS. along with reduced engine power, So, you may have little "slip" at each wheel in the dry, but much more in the wet, so you can never say, "it always works like this" because no two situations are the same. A quick explaination can be found here

A very complicated piece of kit we take for granted, I tested it on a race circuit in Spain under controlled conditions, it was fantastic on the Auris. Kingo

Well, I live in Greece, so 95% of the days is not raining (i.e., the road is dry). So, in dry road, can you take a turn and make the car slip (all wheels, understeer situation) for 1 meter without having the VSC being activated? In my car, I can heavily understeer the car without having VSC activated. When i say heavy understeer, I mean that the car is sliping and, in the end of the turn, it is almost out of the road...

[Parts-King]

I'm not sure you could possibly measure how much distance you travel before VSC works. The way I tried it on a racing circuit was to set out some road cones, whereby you have to swerve violently to the right, then the left, whilst braking hard. If you do this in the wet, with NO VSC, the car goes all over the place, but WITH VSC, you are able to control the car, without "losing" control. It makes a terrible noise whilst under heavy braking as the ABS and VSC bleep is going off. I also think you should be on a good paved road, if you are on loose gravel, all sorts of strange things happen. There will be some sort of workshop test to see if the yaw rate sensor is working. Kingo

[Steve84]

VSC is a great bit of kit. I was leaving a roundabout from one dual carriage way to another. Your trying to get back upto 70mph in a safe but progessive way. Has i joined the carriage way from the island a car moved infront of me with no warning. I hit the brakes, the car slid i was already in the outside lane and heading for the barrier. I started to steer left to pull the car back from the slid the vsc kicked in it seemed ages but was milliseconds really, the car came back on line all was fine. Without VSC i'd of hit the barrier, and been testing the 9 airbags out, luckly enough vsc and abs worked. In my opinon VSC and tracion control should be standerd kit across all cars of all sizes and prices.

[T V O R]

The main reason for VSC is to stop you losing control under heavy braking while trying to change lanes and back again,

rather like the traffic stopping in front of you on a motorway, you braking too late and having to swerve from one lane to another and back again.

I disagree with that.

VSC is to stop you losing control in a straight line while steering and not using the brakes, either going around a bend or taking avoidance action as in your example on a motorway... aka 'Moose test'

Under heavy breaking as you have mentioned, Electronic Brake Force Distribution will kick in along with the ABS, EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining steering control

This can be confused with VSC which will do the same but without the driver touching the brakes.

[Steve84]

VSC contols understeer and oversteer. ABS and EBD sort out the braking side of things where the VSC controls and helps sort out the slid of a car. End of the day VSC EBD ABS all work together has a system giving the driver of the car has much control has possible under demanding condictions. I've drove many cars with ebd and abs, it was none of them systems that brought my slid under control, it was the vsc. (like to say it was driver skill has i do 35k puls a year, but it was not) Has i've said in my preivous post vsc should be standerd spec. I nether mentioned abs and ebd, but abs is almost standerd spec along all cars now anyway.

[Parts-King]

The main reason for VSC is to stop you losing control under heavy braking while trying to change lanes and back again,

rather like the traffic stopping in front of you on a motorway, you braking too late and having to swerve from one lane to another and back again.

I disagree with that.

VSC is to stop you losing control in a straight line while steering and not using the brakes, either going around a bend or taking avoidance action as in your example on a motorway... aka 'Moose test'

Under heavy breaking as you have mentioned, Electronic Brake Force Distribution will kick in along with the ABS, EBD can apply more or less braking pressure to each wheel in order to maximize stopping power whilst maintaining steering control

This can be confused with VSC which will do the same but without the driver touching the brakes.

Sorry I disagree with you. ABS is an integral part of the way VSC works. VSC is designed to allow you to steer the car back into a straight line, which inevitably involves heavy braking. Not many of us would take a violent lane change WITHOUT touching the brakes, it' human nature and the reason you should change your underwear after applying VSC, lol

Kingo

[T V O R]

VSC is designed to allow you to steer the car back into a straight line, which inevitably involves heavy braking.

I don’t disagree about VSC keeping you in a straight line, what I disagree with is that it does it without you touching the brakes.

Maybe this video will clarify things...

Please wait a few seconds for Video to load!

[Mitchal]

VSC contols understeer and oversteer. ABS and EBD sort out the braking side of things where the VSC controls and helps sort out the slid of a car. End of the day VSC EBD ABS all work together h as a system giving the driver of the car has much control has possible under demanding condictions. I've drove many cars with ebd and abs, it was none of them systems that brought my slid under control, it was the vsc. (like to say it was driver skill has i do 35k puls a year, but it was not) Has i've said in my preivous post vsc should be standerd spec. I nether mentioned abs and ebd, but abs is almost standerd spec along all cars now anyway.

I agree that VSC EBD & ABS all work together as a system giving the driver as much control as possible under demanding condictions.

I experienced this first hand a couple of weeks ago. I was returning from Gatwick Airport in very wet conditions on the M23 when I was a distracted by a broken down vehicle. Looking ahead again I saw loads of bright red break lights. I was doing about 70mph (honestly - cross my heart) and just thought "Oh my God!" and down my foot went quite hard. Didn't know what to expect. It felt like I was on loose stones. With the steering held firmly there was no skidding or aquaplaning. The vehicle kept straight within the lane and came to a stop with 20/30 yards to spare. Obviousy the only stick csme from the missus.

[Parts-King]

VSC is designed to allow you to steer the car back into a straight line, which inevitably involves heavy braking.

I don’t disagree about VSC keeping you in a straight line, what I disagree with is that it does it without you touching the brakes.

Maybe this video will clarify things...

Please wait a few seconds for Video to load!

Yes I agree, it does work without you touching the brakes, but my point was, I don't think you would ever have it working WITHOUT touching the brakes. In fact, more to the point, the VSC does automatic braking without you touching the brake pedal, it's part of how VSC works, it applies an amount of brake for you. On my track test, we did it with and without brake application, all I can say is, it's VERY scary when you dont brake, lol. In 99% of incidents, I think you will find you have your foot on the middle pedal. Kingo

[T V O R]

The main reason for VSC is to stop you losing control under heavy braking while trying to change lanes and back again,

I was responding to your original statement that could have been a little misleading, it implies you have slammed on the brakes and the VCS may stop you losing control.

I don't think you would ever have it working WITHOUT touching the brakes.

My point was that VSC works by not using the brakes (by the driver)

In 99% of incidents, I think you will find you have your foot on the middle pedal.

In that case ABS & EBD will do their job.

Either way, I now know that you know how VSC works and hopefully other people who have read this now know a little more about the system

I’ve found another video to show how it works (No ABS or EBD in this... Just Stability Control)

Please wait a few seconds for Video to load!

[frape]

Well folks, I think that you forgot my initial question. Let me repeat it: My new Avensis car has ABS+EBD+BA+TRC+VSC, yet, my car will understeer for more than 600ms (approximately 2 meters lateral movement) before VSC activates (beeping). So my question is whether this behavior is normal? How much lateral movement (slip) is required before VSC kicks in?

Let me also give you one more strange piece of information: When VSC does activate, the car pulls to the right (if the turn is towards the right) but my feeling is that it should deactivate a few milliseconds faster. That is, in the end of the turn, I have to make a small heading correction (i.e., turn a few degrees to the left). Is this behavior normal?

Thank you for your previous posts. I found them very usefull.

[T V O R]

my car will understeer for more than 600ms (approximately 2 meters lateral movement) before VSC activates (beeping).

my feeling is that it should deactivate a few milliseconds faster.

After reading this very useful thread and doing a little more research in my opinion it sounds normal.

I would suppose your car would have to have some form of under/oversteer before the on board computers do their stuff.

What sort of speed are you talking about when your car is doing approximately 2 metres lateral movement? If it’s 40mph plus I wouldn’t be concerned.

Please wait a few seconds for Video to load!

[frape]

What sort of speed are you talking about when your car is doing approximately 2 metres lateral movement? If it’s 40mph plus I wouldn’t be concerned.

Please wait a few seconds for Video to load!

I think the car went with 40-60Km (25-35mph), the road was good, the turn was a sharp 90 degrees right turn, the accelerator pedal was intentionally not pressed at all, and finally, the breaks were intentionally not pressed. All in all, the car had no chance of managing to take the brake. In fact, my old second car (Toyota corolla) would simply go straight in this situation. The turn was so difficult that my Avensis front wheels lost traction and partially blocked. The car moved straight 4 meters (without turning) and then VSC activated. My estimation is that this is equivalent to 2 meters lateral slip.

[T V O R]

You may have a better understanding in snow/ice/very wet conditions when there is less traction. That may be difficult as you live in Greece.

When you try to forcibly under or oversteer, do you succeed or does your car correct itself?

I would imagine VSC wouldn’t have to work as hard on a dry road with good tyres as the grip will be potentially at maximum.

The loss of traction would be down to speed and not snow ice wet leaves wet grass etc etc.

[frape]

You may have a better understanding in snow/ice/very wet conditions when there is less traction. That may be difficult as you live in Greece.

When you try to forcibly under or oversteer, do you succeed or does your car correct itself?

I would imagine VSC wouldn’t have to work as hard on a dry road with good tyres as the grip will be potentially at maximum.

The loss of traction would be down to speed and not snow ice wet leaves wet grass etc etc.

Well, If I try hard, (in dry or wet conditions) the car will understeer/oversteer but VSC will not be activated. It takes a lot of slipping before VSC is activated. Is this the same as your car?

[Parts-King]

You may have a better understanding in snow/ice/very wet conditions when there is less traction. That may be difficult as you live in Greece.

When you try to forcibly under or oversteer, do you succeed or does your car correct itself?

I would imagine VSC wouldn’t have to work as hard on a dry road with good tyres as the grip will be potentially at maximum.

The loss of traction would be down to speed and not snow ice wet leaves wet grass etc etc.

Well, If I try hard, (in dry or wet conditions) the car will understeer/oversteer but VSC will not be activated. It takes a lot of slipping before VSC is activated. Is this the same as your car?

In my limited use of VSC, It is quite difficult to get it to work, unless you perform a violent lane change type of movement, in other words, you cant get it to work unless there is a sudden change of direction, I think there must be certain checks that can be done on the yaw rate sensor and other electronics, to make sure everything is working correctly, I will see if I can find out. Kingo