Strange Traction Control Behaviour On V35?

[vee35]

When I first got my V35 I was quite surprised about how "sensitive" and "aggressive" the traction control appeared to be. By sensitive, I mean it would kick in waaaaay before I would of expected. I do not drive like a hoon, but at low speeds, going around a round-about above "standard" speed, it would kick-in. Doing the speed limit around a sweeping corner, if there was a slight dip in the road or bump on one wheel, it would kick-in.

By "aggressive" I mean, when it kicked in, it would appear to lock the wheels for about 0.5 seconds (which is quite long, and it appeared to be the fronts). It worked safely and all, but it was like my grandmother had tuned the thing...

Is this what others have experienced?

Anyway, I just recently had some work done on the car, and even though I haven't driven it that much, the whole behaviour appears to have changed big time.

Now, it appears to allow the car to go "closer to the edge" before it kicks in; well within safety limits and still there. AND it feels a thousand times less aggressive, in that instead of holding the brakes on for 0.5 seconds, it holds it for about 0.1 seconds; but still very effective (it actually feels safer because you get control back sooner, and there is considerably less forced skidding).

Now the changes that were made, that I don't think would of had any effect are (just for completeness):

1. New Apexi Air filter

2. Z-Tube

3. 5/16" plenum Spacer

Now, the one change that could of had an effect was, a 6 cable Grounding Kit (since the traction control is electronic)

Anyone experience the same? or any ideas? Was this "normal behaviour" in its prior state? or Now?

I could be wrong about all this, as I haven't driven it all that much since the change, but its a definite noticeable change.

[Nightcrawler]

Did you change tyres or wheels at the same time? Or have you had any bushes replaced?

When my lower control arm bushes both went, my car became as you describe, as the traction control could sense the control arms moving with weight changes, and so would go off all the time.

But normally no, they are nowhere like that sensitive, and of course all of the mods you have listed would not affect it. I noticed NO difference when I installed a grounding kit on my 5AT fyi.

[vee35]

Nope, no tyre changes or anything else was done, only the stuff listed above.

So I would guess, you car (mine is also a 5AT) always acted as mine is now acting?

My front tyres are old, but not bald (they just passed rego). They came with my car from Japan, but look old and very very slightly cracked, but still well within safety.

I'll get my mechanics to check my control arm bushes next time its in. Any other symptoms with that?

The other strange thing (which I have hesitated to post as its hard and weird to describe), is that when I brake hard (even from 40km/hr), the front makes a strange sound like a spring or metal stick vibrating (kinda a metallic "boing")

[sonicii]

I find mine too sensitive for my liking too, but it only kicks in when I start to lose traction. For example, jump on the throttle a bit too hard in a corner, as soon as there is the slightest loss of traction on the inside rear wheel, TC kicks in an cuts power..

From the above description, I assume you are talking about VDC, not TC?

TC only reduces engine power when it detects wheelspin.

The VDC system works on the wheel speed sensors, G and Yaw sensors (essentially the same thing). and steering wheel angle sensor. When you turn into a corner, it determines lateral Gs you should be pulling based on the steering wheel angle sensor, if they don't line up, it intervenes. It cannot detect bad suspension components directly, but if those components cause wheel slip, or change in steering geometry, it can trigger the VDC.

Nissan recommend a steering angle adjustment is done when you have a wheel alignment done, to teach the VDC system the correct 'neutral' steering wheel position. I believe this can only be done using consult (although the nissan datascan author is working on an upgrade to his software).

No idea why yours changed with the mods you did. If the grounding kit fixed it, I would be searching for the bad factory ground point..

[FlyingEL]

I'm pretty sure it's your shit tyres. When I just got my car, it came with shit tyres too. After I changed it to better tyres, most of your problem is solved. The Metallic spring sound is actually the ABS kicking in. Which means it senses slip on the tyres. VDC also kick in when you do round about which also work with ABS.

Edited October 15, 2012 by FlyingEL

[Seano350GT]

^{Turning my traction off soon as i start the car is 2nd nature to me now.. I never have it on, unless it's wet. Then i drive like a grandma, my tyres aren't in the best shape.}

^{When i do, for some reason, have traction on during the day it works the same as how Greg explained his.}

[vee35]

From the above description, I assume you are talking about VDC, not TC?

TC only reduces engine power when it detects wheelspin.

I must mean the VDC. I didn't know we had both, and it was definitely the wheels locking up; I think mostly or just the fronts usually.

it determines lateral Gs you should be pulling based on the steering wheel angle sensor, if they don't line up, it intervenes. It cannot detect bad suspension components directly, but if those components cause wheel slip, or change in steering geometry, it can trigger the VDC.

I have been meaning to get my ODB2 up and running, does this mean I will have access to an accelerometer for G forces???

No idea why yours changed with the mods you did. If the grounding kit fixed it, I would be searching for the bad factory ground point..

I'll put it on my list, but when something works....

The Metallic spring sound is actually the ABS kicking in.

OK, so its normal, and its nothing loose.'

Thanks guys.