Why doesn't traction/stability control actually turn off?
 

Hey duders,

I was driving my car in a spirited manner today and noticed that-- despite having held down the stability control off button and gotten the two amber lights on the cluster-- the traction control system engaged a couple of times while trying to slide around some slightly bumpy, vertical hairpins. This is not the first time the system has intervened (while "off") on vertical corners or where there are significant undulations in the road surface.

What's this about? Do I need to do the bloody pedal dance to prevent this? Why does the VSC system tolerate all kinds of retarded shenanigans on flat surfaces / dirt, but freak out the moment there's a bump in a corner?

This is kind of frustrating...

Are you sure? I have not had this problem. When I hold it down for more than 10 seconds, all traction is off. That's why I almost crashed one misty night. If I had sport mode on and VSC off combo then maybe I would've been safe.

Make sure both amber lights are on. This will designate traction and VSC are completely off. If it is off, spinning tires and sliding will be infinite.

From what I've read, the bumps are telling the computer you have wheel hop, so VSC steps in, even though you *think* you have it completely off.

I read that it has to do with Toyota covering their asses so less people will be wrapping their cars around trees. I don't know all the laws in all counties, but it wouldn't surprise me if somewhere, there is a "cars must always have some sort of traction control" law. There's the pedal dance if you want all assists off.

i think theres a way if you just google pedal dance or some jazz like that

The Trac Off light does not mean that the system is literally shut off. It will continue to attempt to save your butt if you get the car extremely out of control, but for the most part will not intervene unless youre being reckless.

This is unfortunately the standard on most new cars nowadays, turning the traction control "off" does not completely disengage the system. Its the auto manufacturers trying to protect themselves from lawsuits. Only the more extreme stuff allows for a complete off traction control system, such as a GT-R or AMG Black Series.

The only way to fully disengage the traction control on an 86 is to disable the ABS, as the two are interconnected. This can be done with the "foot dance" every time you start the car, putting the car into a diagnostics mode that disables ABS, or simply pulling the fuse for the ABS from under the hood. Of course, you now have no ABS system, so doing these methods can be to your disadvantage performance-wise.

Huh, I thought I remembered reading that the pedal dance disabled everything *but* ABS, and that people were still encountering "ice-mode" ABS nonsense on the track while in the diagnostic mode.

If what you're saying is true then this is a major disappointment, since having ABS was one of the reasons I opted for a BRZ over an old, cable-throttle 911. :(

How sad. I guess the good news is that it only happens rarely. The bad news is that it always seems to happen just when I find an appropriate corner (one that will destabilize the car and that I can see through properly)... guess I'll have to plan on being less immature than I'd like to be :D

The funny thing about having omnipresent VSC is that this car is so easy to drive, lol. I'm waiting for a rainy day because the car has so much grip its hard to get it really sliding around in the dry, and when it does slide its so controllable...

This sounds highly plausible based on my experiences. I've been able to get the car super sideways on flat surfaces just fine, but when I hit bumps in uphill corners and the back end "bounces" even a tiny bit, I get the stability control light flashing at me whether I'm sliding around or not. Isn't wheel hop something that happens to high-torque drag cars? Pretty funny that the computer thinks this can happen on a BRZ :P

@lazyluka I'm sure you can contribute here! :D

Good demonstration of the 86's VSC Modes in the wet (note that the handbrake is being pulled to kick the rear end out)

[ame="http://www.youtube.com/watch?v=j8qggahGNH0"]Toyota 86 Traction Control Demonstration [SKIDPAD] - YouTube[/ame]

Upon further review, here is a thread on the pedal dance, it appears to be an update on the last one I read when this was first discovered:

http://www.ft86club.com/forums/showthread.php?t=25494

It seems that the diagnostics mode does not disable ABS, but it does affect the braking electronics in some ways.

It disables EBD (brake force distribution, which meters the braking power when you're braking but turning, to keep the car stable)

There is no such law, at least in the US. From 2012 forward all cars are required to come with stability control but it is perfectly legal to be able to shut it 100% off.

Are people 100% certain that the VSC cannot be turned off entirely? Consider me skeptical.

100% certain. Go drive the car hard enough, your skepticism will (unfortunately) be erased.

This is EXACTLY my experience.

My car is completely stock. I've autocrossed it and gotten it way sideways...no problems at all. However, when driving swiftly through very bumpy turns, I've seen the flashing VSC light in the cluster more than once.

Kind of a bummer :(

Probably try to prevent a rollover.
http://www.webdesignideas.org/images/rollover1.jpg

That's bad form right there: you're not supposed to hit the mirrors :P

I've noticed this behavior on uneven surfaces as well. My theory is that the stability control (specifically the use of individual corner braking to prevent the car from spinning) and traction control (specifically the metering of power + brakes to prevent wheelspin) are indeed fully OFF. However there are at least three features I know of that won't be turned off by depressing the trac off button until the two lights come on.

1. What I think you're seeing is the "auto-LSD" feature. Because the torsen LSD will become an open diff if one wheel is completely in the air; the car is programmed to apply the brake to a rear wheel if it senses that wheel is not touching the ground, or about to break traction. This is pretty easy to achieve with certain suspension setups or uneven surfaces. This feature activating is probably what is causing the "slip light" on the dash to flash at you in corners. This feature is disabled with the pedal dance diagnostics mode.

2. ABS - As far as I know you'd have to pull a fuse to disable ABS. ABS activation shouldn't trigger the "slip light".

3. EBD - Electronic brakeforce distribution. As with ABS, I don't think this feature triggers the slip light at all, and it can be disabled with the pedal dance diagnostics mode, but doing so can have negative consequences (since the ABS system is programmed to rely on the presence of EBD).

It is only a 3 point deduction though!

The last few times I've gotten the slip light it's felt like the throttle was being electronically modulated. I assume if the electronic LSD function took over that you'd still get power delivery to the outside wheel (since the braking would cause the diff to lock up again?), so you wouldn't get the sensation of throttle input being ignored?

I kept my finger on the Traction control button, got both lights, and lost it in a 2nd gear turn with no indication of any aids getting in the way. I know in sport mode, it saved me once again in a 2nd gear turn so I know the difference.

Guess I'll have to find a nice big parking lot somewhere next time it rains really hard and figure it out for myself, hehehehe :party0030:

I was having luck holding the TC switch for 10 seconds+ and was able to slide the car like I wanted. I had an incident where it tried to swap ends on me and after that it doesn't matter what I do even though I get both yellow lights on the TC kicks in just like I never touched the button. How does this happen? I even took it out in the rain and "turned off" the TC and deliberately tried to slide the car and the
TC wouldn't let me. Anyone know what's going on here?

That's weird as hell. If this happened to my car and wasn't correctable I would sell it immediately. Just saying.

I say take it dealer immediately.

I know this could be stating the obvious, but you guys aren't trying to deactivate the TC while moving are you? The traction control can only be fully deactivated (or so the manual says) when you are stationary.

TC and VSC are NEVER fully deactivated by pressing the TC button down for more than 3 seconds.
TC is deactivated by simply pressing the TC button for a short period, but this will keep VSC ON and TC will re-engage past a certain speed limit (don't remember off by heart now, but its something low like 40km/h).

The above is true regardless of if the vehicle is moving or stationary.

Sometimes the light will flash and it won't intervene (it will but you won't notice it, possibly due to loss of traction by lift/bump on one wheel or something similar due to torsen LSD) or other times it will emergency brake for you.

The only way to turn TC off fully as mentioned before is Pedal Dance (which keeps ABS functionality) or to pull the ABS fuse which also disables ABS functionality. I do not suggest doing either of these on the public roads. The car does have an EDR and if it is shown you have used either method you risk you claim being declined by your insurance* as this was beyond the "normal" scope of operation that the car was designed for. In another words, the manufacturer did not specify this in the user manual therefore it can be considered as a modification to the vehicle, even though it is temporary.

If you want to know how I know, it's because I used the 3 sec off system, and the car saved my a** when I lost control and started going backwards due to a 180 spin. It managed to slow me down (by performing an emergency brake) to 17km/h before I rolled off a cliff. I have a few emails from Toyota describing the system operation.

The pedal dance/abs fuse was not discussed with Toyota as I didn't see the need to.

*I am not an expert on this subject, but this is what I have concluded with dealing with my insurance company here in New Zealand. I had a nice friendly chat to them regarding the TC system affecting insurance and that was the conclusion I came to after the talk.

VSC is good to go, but as soon as I press traction/stability control off the fucker turns back on just as Im driving normally. And if I try drifting around a corner it turns back on instantly as Im trying to drift. I even tried holding down the button as Im drifting and it still turns back on lol

Here's a question. VSC sport in videos I've seen seems to allow moderate drifts around turns. I know it obviously allows for a larger slip angle, but that all seems kind of pointless to me because it doesn't seem to increase the TCS margins at all, so say I'm on a wet curve, and I wanna have a little fun. Unless I do some sort of Scandinavian Flick, I can not get the back to step out, because trying to do so with the throttle just leads to the TCS stepping in to stop wheelspin. Even if I DO flick the car into the turn, I can't do anything with the throttle to prolong the turn because TCS will step in. It's really irritating because IMHO, it seems to render sport mode completely useless to me. As a result i never use it. I'm just in normal mode most of the time, or full off. I'd love to leave it in sport mode so that I could have that added margin of safety, but the car doesn't seem to let me do anything at ALL in that mode.

Stop your car. Hold the button until the two amber lights come on. Now your traction is "off". When you press it once it sort of acts like a launch control. It will allow a little bit of slip, then catch the tires.

Yeah, sport mode doesn't really let you drift or anything, it just lets you drive the car hard. You can add throttle in a corner to the point where you feel a little suggestion of slip, like the rear end is just smearing a little bit around the corner, but the computers will stop you as soon as you get any visible yaw rate going.

Sport is perfect for street driving-- just enough leeway to let you enjoy yourself. If you want to go sideways in the rain / snow / whatever you just have to turn it off (as everyone's said, hold down the off button until you get the two amber lights).
@Stang70Fastback I liked your parking lot video :3

Pretty much spot on. I'd like to add that the tcs "off" setting will still kick in at extremely sharp yaw rates like getting 70-80% sideways around a 90* corner. It's pretty frustrating because I've been in the zone, ready to accept the slide, then all of a sudden NOPE CAN'T DO THAT, SORRY kicks in and screws you all up and makes you look like you can't drive.

I too have 'bumped up' against the auto LSD in the past, thinking I could have some fun but ended up looking like a clown when the car recovered itself. But at least at the track (Buttonwillow) it doesn't seem to matter at all what mode VSC is in; even fully on, not in sport mode, it allows for a very slight drift outward and I've only once seen the dash light flash. But for the most part I leave it in sport mode for all track days.

I found this video helpful when i was asking these questions:[ame="https://www.youtube.com/watch?feature=player_embedded&v=j8qggahGNH0"]Toyota 86 Traction Control Demonstration [SKIDPAD] - YouTube[/ame]

When I turn the nannies off, they stay off unless it detects a wheel off the ground. I've spun it enough times to know... :-p

i feel like the auto re-engage has been changed as the newer models come out. people have said on here that they have to hold the button down and then it still re engages over 30 etc however on my 15 i have never had to hold the button down, the trac turns off and does not re engage unless i push the button once again.

I've a 2013 FR-S and holding down the TCS button for 3 seconds gives me the two lights, whether I'm moving or not. They stay on until I turn them off.
There does seem to be some throttle modulation intervention at large slip angles.
I'd like it if the pedal dance would allow EBD to continue to function, as EBD is AWESOME.

Perhaps the bumps scare the system because of the torsen diff. They don't like it when a wheel comes up.

I have a 2012, and I've never felt any intervention as long as my wheels stay on the ground. If I lift a wheel the sliplight comes on momentarily, and immediately disengage again once contact is made.

I'd be interested in some feedback from people with clutch LSDs.

^^ Both lights on with a 5+ second hold, just a wee bit of slip and throttle gets cut while lights are flashing. Takes all the fun out of sliding a corner when it's wet or sandy/snowy.

Found this. [ame]http://youtu.be/dj7WIlliwgQ[/ame]

I'll try to remember on the way to work in the morning.