Second Generation Nissan Xterra Forums banner

1 - 14 of 14 Posts

·
on line
Joined
·
358 Posts
Discussion Starter #1
First, What does VDC do?

Can VDC be turned off in 4WD?

How is VDC, Slip and the ABLS (LSD) all connected?

We are used to vehicles without all of this electronic BS. We are noticing that in the snow/ice if the Xterra is understeering/not turning you can't give it some gas and drive out of the slide. The electronic BS just reduces engine speed and the gas pedel does nothing. This happens with VDC on or off. Is there a problem with my VDC?
 

·
on line
Joined
·
641 Posts
Gerdo said:
First, What does VDC do?

Can VDC be turned off in 4WD?

How is VDC, Slip and the LSD all connected?

We are used to vehicles without all of this electronic BS. We are noticing that in the snow/ice if the Xterra is understeering/not turning you can't give it some gas and drive out of the slide. The electronic BS just reduces engine speed and the gas pedel does nothing. This happens with VDC on or off. Is there a problem with my VDC?
Information regarding VDC: http://en.wikipedia.org/wiki/Electronic_Stability_Control

AFAIK, you should be able to turn VDC off.
 

·
on line
Joined
·
15,651 Posts
VDC = Vehicle Dynamic Control.

With VDC on it uses the ABS sensors in the wheels and a Yaw sensor in the center console to detect if the tires are loosing traction or if the body is leaning too much. It will then cut power and/or apply brakes to certain wheels to try and keep the vehicle from losing control.

When the VDC is working, the SLIP light will flash.

With VDC off, it should not cut power, but it may still try and transfer power to wheels with more tractions.

VDC can be turned off in 4Hi and is automatically turned off in 4Lo.

VDC and the ABLS (Active brake Limited Slip) uses some of the same sensors and lights, but perform different functions.

ABLS uses the ABS sensors in the wheels to detect when one wheel is spinning excessively faster than it's mate (the wheel on the opposite side of the vehicle). If should detect this, it will apply the brakes in a pulsing manner to slow that wheel down and transfer the power to the other wheel.

When ABLS is working, the SLIP light will flash.

You can not turn ABLS off.
 

·
on line
Joined
·
331 Posts
you can turn VDC off but not while you are moving. You will know it is off because a light on the dash will light up saying "VDC OFF"
 

·
on line
Joined
·
2,875 Posts
i've turned off VDC numerous times while moving. for example, when going into sand using 4x4 hi, i shut off vdc (vdc stays on by default in 4hi but turns off in 4 lo) while moving. It is obvious it turns off because the light comes on (vdc off) AND i don't get all those weird noises I would get with it still on, been there done that..

so, you CAN turn vdc off, then on or whatever while moving or stopped, doesn't matter.... as far as I can tell in my experience and what the manul says...


:)
 

·
on line
Joined
·
295 Posts
Incidentally having both "sissy bars" disconnected hasn't effected the operation of VDC or ABLS in the slightest.
 

·
on line
Joined
·
358 Posts
Discussion Starter #7
Does anyone have a wiring diagram of the VDC switch. I had it out and ran continuinty check on it. With it out none of the 4 pins connect. When pushed in only two connect. The other two never connect to anything. Maybe I have a bad switch. I need to see a wiring diagram!
 

·
on line
Joined
·
358 Posts
Discussion Starter #8
We went out to play in the snow and we have snow, 16" in the last few days. Here is what I found.

It doesn't matter if VDC is on or off, nor does it matter if you are in 4hi or 2hi. ABLS (LSD), ABS and Slip sensor/light are always active.

VDC on: VDC will incorperate the above systems and also will apply the brakes and reduce engine speed to try to pull out of a slide. When the VDC is "active" it doesn't matter how hard you push on the gas pedal the engine will not rev up.

VDC off: The above systems will be active but the computer (VDC) will not adjust the engine speed. You have full controll of the revs/power. This will alow a skilled driver to power out of a slide.

It appears that the VDC is working properly.

Note: VDC is automatically turned off when in 4lo.
 

·
on line
Joined
·
358 Posts
Discussion Starter #10
You are right there isn't a "slip" system unless you consider the light and the sensor to activate the light. I guess what I was saying is that the slip light will still flash if the ABLS kicks in.
 

·
on line
Joined
·
20 Posts
Don't have an X (yet) but my wife's VW has the Bosch version of this system (called ESP in the VWs). The VW is an all-wheel-drive.

Frankly, it's amazing in her car. We have a 1/4 mile driveway that is mostly gravel and flat for the most part. So, when it ices over in the winter (like it is now) I can play with the car. It's actually hard to get the vehicle to really slide out. In her car, I can disable the power cut which does allow more 'fun', but I can't 100% disable it. I have not seen any issue with regaining control with the system on no matter how much I get the car out of whack.

I wonder if you might have some kind of issue, or maybe the Nissan system isn't as effective. Guess I'll find out next winter (not getting my X until at least March)
 

·
on line
Joined
·
1,739 Posts
The handling in the snow is likely due to your experence driving front wheel drive cars vice the rear wheel drive Xterra.
 
1 - 14 of 14 Posts
Top