VSC, TRAC & other STAR system experiences

[MicaBlue03]

I hesitate to start a new thread, but didn't see this subject covered in a general way so I thought I'd give it a try. I figure if we explain some of our experiences with these features that are supposed to save us from little disasters, we may be able to take better advantage of their benefits and know their limits.

I've experimented with VSC and the other stuff on purpose, but last night may have been the first time I had VSC intervene in normal driving. I was in the middle of a long, gentle left-hand bend going only 20-25 MPH when the rear end began to slide out on me. It was cold, but things weren't slick elsewhere, even in spots that were icy or snowy. The slick spot I found had seen enough sun and then shade to freeze a very thin and very smooth area. That, combined with the turn and a little extra crown in that area are what provoked the start of a spin (you could also call it oversteer). At the time it happened I had been in complete steady state, not changing speed or steering input at all. The onset of the spin was entirely smooth and gradual, and if I hadn't been paying close attention I wouldn't have felt it as early as I did.

The whole thing only took about 3 seconds from start to finish. I started to feel the rear end sliding out and was just starting to move my hands to steer into the skid. The vehicle had rotated maybe 20 degrees counterclockwise in about a second. The 4Runner began beeping rapidly, the dash light blinked, and I could feel the brakes acting on one or both wheels on the right side. Before I could make any significant steering input the vehicle had straightened out with no overshoot and I was back on course. The beeping stopped and the drama was over.

Some folks have questioned the usefulness of stability and traction control in very low traction situations, but I think I see the benefit of this stuff even when normal steering and acceleration/braking would be pointless. The ABS can do things that I can't (like braking one or both wheels on one side), it can act faster than I can, and it is never distracted by a spouse or a screaming kid in the back seat or a mobile phone. I was paying reasonable attention in this case, and the system still beat me to the punch.

In situations like this there are several benefits beyond just avoiding a trip into the ditch. For example, depending on how the traction situation changed during the spin, I could have lurched into the oncoming lane or simply not had enough steering traction to recover in time. By the way, I've heard that these systems sometimes only brake the *rear* wheel on one side, and I suspect that is to preserve the maximum amount of grip for the front tires for steering. Perhaps others can clarify this.

I have another (shorter) story about "brake assist" but that can wait for another time.

 

[sharp4runr]

Nice detailed story! Almost felt like I was in the passenger seat with you!!!

I've never had VSC kick on during normal driving, only when it snowed and I wanted to see what it could do. Road was completely empty and I took a corner quicker than I should have and the darn thing kicked in on me. It was the first time I ever played with it, so the beeping was an annoyance and more of a distraction if you ask me. I've already got more to worry about and I'd rather not be bothered by the beeping.

Also had the HAC kick in during driving. I was stopped on a pretty steep incline on a regular road and I could have sworn I let the brake go for a second to switch over, and I hear the breaking and the vibration. Then it beeps at me again. I step on the gas and just take off. I thought it was suppose to do that after 5 seconds but I guess the sharp incline caused it to kick in faster.

Thanks for sharing.

 

[Mark86]

I've had the VSC come on once since I have 4Runner. I just had my truck washed and finished drying it when I began to pull out of the carwash. I then realized that I did not dry it well so I pulled to the side of the carwash lot and dried my truck again. I did not realize that I pulled over where they armorall the tires. I forget to say that the temperatures were way below freezing. So I get back in and go to make my left turn out of the carwash. I am only going about 5 mph but I feel my backend fishtailing. Then I hear beeping and the VSC light on my dash is on. Once that clicked on, it got my truck straight within a second. The whole event only took around 2-3 seconds. It was scary but the VSC worked like a charm. I did not lose control or spin out (I was lucky because there was oncoming traffic). That VSC system is really great.

I also have some experience with the traction control but that was done on purpose by the driver!! For example, accelerating too much on snow or stopping short on ice. Believe me, this was done on deserted country roads!!

 

[T?@\7]

Wow, im glad to know that these systems have the capabilities necessary! good story

 

[tkr128]

Excellent write-up! It's good to hear an actual experience and not Toyota praising the usefulness of it. It's nice to know it works.

I've only had my VSC kick in once. I think I hit a pothole...though I'm not sure why that would have tripped it.

 

[leftyrb]

I have dedicated ice winter tires (Bridgestone Winter Duelers) and despite this, have had both the traction control and VSC engage. We have had a lot of ice covered roads around here, and taking a corner too tight is sure to engage the VSC. I got up a hill to leave my residence, and if I accelerate too quickly the traction control will do its job. I am pleased with these features and Toyota offers them as standard on even the base model!

 

[ToyotaDoodz]

I've had this happen with VSC on windy gravel roads. It kicks in before you can react and I knew it was going to happen but it still beat me to the punch.

ABS is great to. I'd never have another vehicle with out it.

The gist of your VSC story explains why I like the full time 4x4 so much. There have been many times that there was not time to stop and react to shift into 4x4. It was already there and kept me out of trouble.

 

[TranceKrayz]

i too have had the same thing happen to me while making a simple left turn. the road was pretty wet, and the rear end came loose. unlike you however, when i felt it comming i quickly went to steer into the skid (about the same time the VSC kicked in) so it felt a little more dramatic because the truck then wobbled. I guess this is the reason why some folks may question the system, but i think once you adjust to it, then it works very well.

 

[Thai]

I have been preaching to my friends and family about VSC since it first came out...the concept is so simple yet so elegantly designed. It saved me once or twice in my 4runner, too many times in my M3 (yes, damn sports car!), and a few times in my G-wagen up in the Colorado moutains.

I honestly love these electronic safety nets...it just shows that my driving skills are far from perfect!:

 

[Hank]

nice write up guys! btw, since the 4R has VSC aren't you supposed to steering in the direction you want the car to go instead of steering into the skid? (e.g.- if the rear swings left, you steer right to keep the vehicle on course instead of left to counter the skid). I've never tried it myself, but maybe I will head up to the mountains soon to test it out.

 

[dcampen]

VSC aren't you supposed to steering in the direction you want the car to go instead of steering into the skid? (e.g.- if the rear swings left, you steer right to keep the vehicle on course instead of left to counter the skid).

I don't see why having VSC would mandate that you steer in the opposite direction from what you would without VSC. With or without VSC you steer the same. VSC just assists. If the rear swings out to the left and you steer to the right you are probably going to put the car into a spin despite the best efforts of VSC.

"Steering into the skid" is steering in the direction you want the car to go. If you are turning right and the rear swings left then now the vehicle will be rotated too far clockwise so you steer left because that is where you want to go.

 

[Hitman]

Also had the HAC kick in during driving. I was on a pretty steep incline on a regular road and I could have sworn I let the gas go for a second to switch over, and I hear the breaking and the vibration. Then it beeps at me again. I step on the gas and just take off. I thought it was suppose to do that after 5 seconds but I guess the sharp incline caused it to kick in faster.

I've experienced the same exact thing.... I'm not too sure how the system was intended to work, but it sure seems like it doesn't do much to me....

 

[Hitman]

I don't see why having VSC would mandate that you steer in the opposite direction from what you would without VSC. With or without VSC you steer the same. VSC just assists. If the rear swings out to the left and you steer to the right you are probably going to put the car into a spin despite the best efforts of VSC.

"Steering into the skid" is steering in the direction you want the car to go. If you are turning right and the rear swings left then now the vehicle will be rotated too far clockwise so you steer left because that is where you want to go.

All stability assist systems use steering angle as a major consideration to determine if the vehicle is off the driver's intended path.

The system will cause the vehicle to act differently if, say, you have the steering wheel sharply to the left and then rapidly turn it to the right. I've experimented with my 4Runner recently in an empty, snow-covered parking lot. It seems to me that it is better to keep the wheel turned in your intended direction instead of steering into a skid, as we all are used to doing.

Think of ABS.... we had to learn to avoid pumping the brake pedal with ABS-equipped vehicles.... maybe we need to learn to change our steering habits with stability assist now too.

Anyway, I think stability assist and ABS work very well together in low-traction situations. When I was experimenting in the parking lot, I felt that the vehicle will go where I point it regardless of the lack of traction. Obviously, it won't respond as quickly as it would on dry pavement though.

 

[Kanab]

Just read an editorial in one of the auto mag's on this subject. It stated that these new features have/will save more lives in the future by helping to eliminate single vehicle accidents. They said GM/Ford etc were working on making them standard on all vehicles. I feel lucky that both my vehicles has VSC, but I understand that you still don't want to drive a 350Z in the snow with summer performance tires

 

[boston_kevin]

Nice detailed story! Almost felt like I was in the passenger seat with you!!!

Also had the HAC kick in during driving. I was on a pretty steep incline on a regular road and I could have sworn I let the gas go for a second to switch over, and I hear the breaking and the vibration. Then it beeps at me again. I step on the gas and just take off. I thought it was suppose to do that after 5 seconds but I guess the sharp incline caused it to kick in faster.

I though HAC was only supposed to kick in if the speed was 0 mph and you just took your foot off the brake to switch to the gas. It only lasts for a maximum of 5 sec.

 

[Luxury]

I've had the VSC come on once since I have 4Runner. I just had my truck washed and finished drying it when I began to pull out of the carwash. I then realized that I did not dry it well so I pulled to the side of the carwash lot and dried my truck again. I did not realize that I pulled over where they armorall the tires. I forget to say that the temperatures were way below freezing. So I get back in and go to make my left turn out of the carwash. I am only going about 5 mph but I feel my backend fishtailing. Then I hear beeping and the VSC light on my dash is on. Once that clicked on, it got my truck straight within a second. The whole event only took around 2-3 seconds. It was scary but the VSC worked like a charm. I did not lose control or spin out (I was lucky because there was oncoming traffic). That VSC system is really great.

I also have some experience with the traction control but that was done on purpose by the driver!! For example, accelerating too much on snow or stopping short on ice. Believe me, this was done on deserted country roads!!

Wow! Everyone has a lot to say about this. Here’s my experience so far:

Traction Control (I think)
I had the same carwash scenario happen twice, and it wasn't even very cold, just all the oils and soaps I guess. But, I don't think I have ever experienced VSC because I don't remember any beeping or lights. Just the clicking sound (from my rear wheels) that I am guessing is associated with the traction control. Whatever it was, it saved my ass. As soon as it kicked in, my tail and tires stopped rotating and it was all-good. This was no deserted road here.....it was Beach Blvd, which is at least a 4-lane road each way........so I was extra happy with my 4runner.

ABS (I think)
Last weekend I went under an overpass that is below sea level in Santa Barbara and it must have been high tide, because it was super slick. I knew the area could get bad, but didn't think it could be this bad. I braked early and nothing, just kept going at the same speed, braked harder and kept sliding. Guess the ABS realized I was stupid, needed to pump the brakes or something, and kicked in. It let the tires rotate incrementally, which helped a lot in the last 1/4 of the distance I slid. I stopped just before the red light beneath the overpass.

 

[Northof49]

My HAC kicks in everytime I back out of my driveway.....that's what happens when you live in the side of a cliff lol.

In the winter the VSC kicks in fairly often, as there are lots of slippery 90 degree turns on the way home. The system works very well, however, I still wish there was a way to turn it off for normal driving (without locking the diff) so that I could slide it around a bit more when wanted.

For everyday driving tho, particularily on the highway, it is a very nice safety net for the unexpected and definetly does things that even the best drivers couldn't.

 

[sharp4runr]

I though HAC was only supposed to kick in if the speed was 0 mph and you just took your foot off the brake to switch to the gas. It only lasts for a maximum of 5 sec.

Thanks for pointing that out, I meant I let go of the brake to switch over. I'll edit my original thread. Sorry for the confusion...

 

[MicaBlue03]

Hitman's experience squares with my own (both deliberate and accidental!). I agree with dcampen that the general advice to "steer into the skid" would have usually have you pointing the front wheels in the direction you want to go, and that would make sense to the brains of the VSC system as well. That's logical from a human factors point-of-view too, since it's not reasonable to expect drivers to remember to do something different in stressful situations, depending on whether or not they know they have VSC. Maybe instead of being told to steer into the skid, we all should have been told to "point the front wheels in the direction you want to go"(?).

The 4Runner does indeed have a sensor to tell it the driver's steering intent. It also has one or more accelerometers (in the center console near the shifter) to tell it which way the vehicle is actually moving, and presumably which way it's rotating. If the steering and actual motion are significantly different, you get the urgent beeping. The steering sensor is how you can reliably provoke the beeping if you're experimenting in a safe place--just turn the steering wheel more rapidly than the vehicle can possibly follow and you'll hear about it.

TranceKrayz's reflexes are faster than mine, and apparently it's possible to confuse the system a little if you are fast enough and aggressive enough. I doubt it would be a problem in normal driving, but offroad situations might be more variable. The Toyota system is pretty conservative and doesn't require any driver training, but it would be interesting to have an "aggressiveness" knob and or some switches to more selectively disable things. Some have said that the system is less invasive at higher RPMs, but I don't know. I also don't know if the system will do less de-throttling if you push the pedal all the way to the floor.

BTW, perhaps because of its intended use offroad, the 4Runner has special wheel sensors for the ABS/VSC/TRAC, etc. Most ABS sensors can't tell direction of rotation and don't work below 5-10 MPH, but the 4Runner's can read rotational direction and speed from each wheel down to something like 0.1 MPH. And yes, this means the whole shebang works in reverse, too! Try it if you get the chance.

It's interesting to hear that folks like GM, Ford, Jeep, etc. are planning on putting these systems in more vehicles. I'm guessing they've not had these as standard equipment in their SUVs up until now as a way to keep the entry prices down. Having it in more vehicles is mostly good news, but the domestic brands haven't had such good luck so far in making complex systems like this truly reliable. When you think about the whole group of things--VSC, TRAC, HAC, HDC, EBD, brake assist, ABS, and throttle-by-wire--I'm glad mine are all on a Toyota!

 

[Hank]

Hitman's experience squares with my own (both deliberate and accidental!). I agree with dcampen that the general advice to "steer into the skid" would have usually have you pointing the front wheels in the direction you want to go, and that would make sense to the brains of the VSC system as well. That's logical from a human factors point-of-view too, since it's not reasonable to expect drivers to remember to do something different in stressful situations, depending on whether or not they know they have VSC. Maybe instead of being told to steer into the skid, we all should have been told to "point the front wheels in the direction you want to go"(?).

The 4Runner does indeed have a sensor to tell it the driver's steering intent. It also has one or more accelerometers (in the center console near the shifter) to tell it which way the vehicle is actually moving, and presumably which way it's rotating. If the steering and actual motion are significantly different, you get the urgent beeping. The steering sensor is how you can reliably provoke the beeping if you're experimenting in a safe place--just turn the steering wheel more rapidly than the vehicle can possibly follow and you'll hear about it.

Nice write up, but I was a bit confused. I've never experience a skid in my 4R yet. So are we supposed to steer into the skid (countersteer) or steer in the direction we want the 4R to go? I don't recall the owner's manual stating what to do in a skid, but the owner's manual for my dad's ML320 states that you should steer/point the wheel in the direction you want to go (intend path of direction) instead of steering into the skid as that will confuse the VSC system