The fronts were mounted at a completely different time than the rears. No mix up with the proper front wheel/ rear wheel combos because the fronts were mounted and balanced before the rears came back from being painted. So the theory of a mixup there is no good.

The tires are all brand new, as stated before. So excessive tread wear is no good.

I know we sometimes overlook the obvious, so I got on my hands and knees today and closely inspected each tire, as to insure that the sizes are as stated.....Indeed they are.

I stated earlier in the thread that I am new to the Nissan scene.....hence my screen name NismoNEWBIE. I have discovered that in my short time of being a Z owner that most people that own one are often confused by their own trim levels. So if it has VDC then it must NOT be an enthusiast, as I claimed earlier. That seems irrelevant to the problem. The car has VDC, and the car has a problem. Arguing over whether it is an enthusiast or not seems rather trivial to the original intent of my post which would be trying to solve a problem.

SO, if pictures would help (I have no idea what this would solve), other than proving to all of the fellas that I'm not an idiot, I'll be happy to post some. Just tell me what you want to see.

 

What about the behavior of the car when the VDC off switch is depressed?

 

No one accuses you of being an idiot. Your VDC problems and tire size history is a learning experience for many of us. What we do know is that 2004 VDC is sensitive to overall tire height, and the difference between front and rear tire circumference.

Some racers put 16 and 17 inch wheels on the Z and the Z is fine. Other drivers mix 17 inch wheels and tires, and VDC objects. Who knows.

 

I wouldn't mind knowing that too, if so it would say steering agle senser all over it.

 

No one here thinks you are an idiot. If people thought that, they would have left the thread long ago.

My idea with pictures was verifying that you in fact have 17” wheels. Original equipment on VDC-equipped cars includes 18” wheels and not the 17” wheels you have. If you have VDC with 17” wheels, they are not OEM wheels. You report mounting 225/50-17” front tires. No chance these front tires could be 225/50-18”?

That might seem like a stupid question, but VDC-equipped cars are delivered with 18” wheels, and I’ve learned here not to assume anything.

Just trying to provide help,

--Spike

 

I bought the car 6 months ago, it was not purchased new. They are, in fact, the 7 spoke factory Nissan wheels that are 17 inches in diameter. It is very posssible that my car was originally equipped with 18" wheels. However, as clearly stated earlier the car has 17" wheels on it. With a 225/50/17 onthe front and 255/50/17 on the rear. The assumption that I don't know what kind of wheels are on my own car, is ridiculous.

How about a yaw sensor. I'm being told that there is a box under the center console that sometimes people disable to drag race, drift, or road race. Any chance this box may have something to do with it?

If the car did, in fact come from the factory with 18's on it, would the computer be set up to only accept 18's or larger wheels? This would partly explain why it never happened with the 19's on the car.

Someone mentioned the VDC button. When the button is pressed it does nothing, doesn't light up or anything....this is obviously a problem.

 

225/50-17” front and 255/50-17” rear is at the limit VDC will tolerate, so depending upon the specific tire and the manufacturer’s specific sizing, you could possibly have problems with VDC. But you mentioned running 235/50-17" and still having the problem, so it's something more than the tire size.

Re> "If the car did, in fact come from the factory with 18's on it, would the computer be set up to only accept 18's or larger wheels?"
No. It’s the overall diameter of the wheel/tire setup that is important, and not the wheels size. VDC operates equally well with 17”, 18”, 19”, or 20” wheels.

When you toggle the VDC button, you should see “VDC OFF” illuminated in lower left section of the speedometer gauge. If you don’t see this, VDC is not operating correctly.

Looks as though DaveZ#3 and terrasmak had the right instincts here:
But… I have no idea why your VDC would stop operating by simply just swapping tires and wheels.

--Spike

 

Don't mean to butt in here but the problem on my 06 enthusist with TCS.
I have narrowed it down the type of tire. It could be the tires you have on those rims. The same thing happened to my car one winter i put in GOODYEAR eagle f1 all seasons and another winter i ran some nittos it seems to be some materials in some tires throw off the signal to the speed sensors. The only thing i could find that the tires had in common was carbon fiber composite some crap.
So i figured it had to be the tires because when i run my summer wheels "OEM Grand Touring wheels with potenza REo5o RFT's" its perfectly fine.

BTW my bro inlaw had the same issue with some hankook tires on his 08 touring with VDC

SO Im PRETTY CERTAIN ITS THE TIRES
not the size not the sensors or anything else

I understand how annoying this cold be any slight turn or bump on the road it kicks in and the car wants to fall on its face

 

^^ Yet another set of tires, you say!

The poor guy has already mounted three different sets of tires on the car. I doubt he will want to try another set of rear tires.

He reports that the "VDC OFF" light does not illuminate on his dash when he toggles the VDC switch. That sounds like an electronic failure.

--Spike

 

Alright Spike, how about the yaw sensor? I'm told that there is a small box under the center console that controls the roll and traction of the car. I'm being told that some people wire some kind of toggle switch to disable this feature in order to drag race, drift, or road race. I'm gonna try to mess with the car some more tomorrow. Kinda tough to do when you work and get home and it's dark. Thanks for all the input...keep it coming.

Any ideas why the VDC button may not be working??

 

Toggling the VDC button actually does not disable all of the VDC functions (an example being that VDC remains active). Some members here do more to defeat VDC, including pulling a fuse and changing the wiring. Of course they are in “uncharted waters” when doing this, and that screws-up a lot of things and doesn’t provide a reliable result. If you search on “VDC,” you see the things some of our members do to disable VDC completely.

There are three points we need to address to answer your problem/question:
1) Why did your car run fine with VDC and 19” wheels?
2) Why did replacing the 19” wheels with 17” wheels result in VDC failure?
3) Why do you not see “VDC OFF” when toggling the VDC button?

It’s looking more like the previous owner messed big-time with the VDC function. But of course, that would not have anything to do with the failure you describe (where VDC worked fine with 19” wheels and does not work with 17” wheels).

--Spike

 

hi ,i wanted to chime in on this im running ventus v12 evo 225-40/19 93y front and 255-35/19 96y rears the fronts are 7/10th the rears have about 800 miles on them.i thought this issue would go away withtime but its still there .
if i make a right while slowing or on the brake the left rear abs kicks in.
its done this a few times in the opposite direction but not as frequent.vdc off it still occurs! not as much .i disconnected the yaw sensor everything opperates fine even the abs. next step is to put the factory wheels back on and plug in the yaw sensor to see if it still happens.
any input is the wheel size the problem?

 

ok just switched to the stock wheels problem has gone away! thanks for all the help everyone especially dave

 

Its your tire size, 255/40 or 245/40 would be the proper rear tires to match the fronts.