VDC off, but slip light blinks

Pharmacist

Ok after digging through the user manual, I found some info that may explain a few things, though also raising more questions than it answers.

On page 2-14, it states that the slip indicator light activates when either the VDC (which I assume is mainly concerned with preventing over/understeer) or the traction control (which I assume is mainly about reducing wheelspin during hard acceleration) is activated. It says the light is activated to warn the driver that the vehicle is near its traction limits. On the same page, it says the VDC off light comes on when the VDC off button is pushed, which switches off both VDC AND traction control.

Now on to page 5-27. It talks about VDC using brakes and reducing engine power to keep the car on the steered path i.e. prevent over/understeer. It states that the VDC also uses active brake limited slip (ABLS) to improve traction. It says the ABLS applies brakes to one of the driven wheels if it spins too fast on a slippery surface in order to divert power to the other wheel. This sounds a lot like the traction control system mentioned previously on page 2-14. However, the words "traction control" are never explicitly stated in this section. To make things worse, the manual seems to contradict itself. It further states on page 5-27 that even if the VDC is turned off, the ABLS system remains operational, and if it is activated it will cause the slip indicator light to blink. Note that this contradicts what was mentioned in page 2-14, that the vdc off button turns off both the VDC and traction control. However, it does seem consistent with what I experienced during my drive, with the slip light blinking even though I didn't feel any braking effort on the rear wheels.

Is this an error in the manual, or are traction control and abls different things?

Modshack

They are somewhat different. They use the same hardware though in different ways..

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Pharmacist

Care to elaborate?

Modshack

Well...as you get to a brake lock-up situation, the ABS sensors detect this and release the brakes to keep the wheel rolling and maximize braking traction. (this happens very rapidly and is felt in the brake peddle as a pulsation)

Traction control is kinda the opposite...When wheelspin is detected the sensors determine this and the brakes are cycled on rather than off to accomplish essentially the same thing (traction)

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Pharmacist

No no no no no. What you are talking about is ABS (antilock braking system). That is what prevents wheel locking during hard braking on slippery surface. What I meant was ABLS (active brake limited slip) which operates by braking the faster spinning wheel during hard acceleration. Pretty much the same as traction control and electronic limited slip differential and all the other names its given by different car manufacturers. It's described in detail in page 5-27. Which is exactly the cause of confusion since the manual says traction control is turned off with the vdc button in one section but in another section it says abls stays on even if vdc is off.

Yes, I do know that traction control/abls/electronic lsd/etc..... is nothing more than a software program added to the already existing ABS software and hardware. And that's why a sure way to totally kill off traction control in any car is pulling out the abs fuse.

G37Sam

Thanks for the link modshack, fuel doesn't cut off if you brake-launch till like 1.5-2k rpm. But if you try doing a burnout like this



It won't let you lol

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omnomz

I've turned off everything several times pushing the VDC button at the exact perfect timing. usually when the car is cold, ive done it once when the car was warm. the BRAKE light ABS light and slip lights all come on, no ABS or TCS.

Pharmacist

Huh? Turning off the TCS has nothing to do with the car's temperature. And turning off ABS is not possible in this car or any other car I know off unless you pull the fuse. Also, brake light should not come on. It seems that you have a malfunction of some sort in the brake hydraulics or electric system.

import111

I have done the same thing omnomz has done. He is right about the ABS light coming on with the VDC light if you hit the VDC button at the right time...however I never did test it to see if ABS was actually dissabled.

pgrmstr

I went through this question myself some time back and what I was able to figure out is with VDC off, traction control and vdc are disabled.

You can do burnouts, power slides, and anything else you want. I have the sport so have the vLSD. The ABLS light comes on occasionally, but I think its only when one wheel starts to spin before the vLSD locks up....whether it applies brake or not I couldn't really tell, but I think its only momentary until the LSD locks and then you can continue to power slide all the way to rev limit...

I'm pretty sure I only experience it in low traction conditions such as rain and have not noticed it during dry conditions...

Pharmacist

Bizzare. As far as I know, neither the z nor any other car for that matter offer the ability to turn off the abs. That's actually one issue I had with car manufacturers since abs activation can be extremely dangerous on snow, mud, and gravel. Heck, I was even planning to use that unused button on the center console as an abs switch by splicing a switch into the abs wire at the fuse.

Care to elaborate on how you do it? When exactly do you push the vdc button, and for how long? And does it always work or is it inconsistent?