I was under the impression that VSC and TRAC was turned off with the center diff locked and in low based on this info from another site:
**This is NOT correct. Defeating the TRAC when center locked defeats the purpose of having it. With my center locked the TRAC system works when needed. It's ASC that is disabled when the center is locked.**
"Beginning with the 2000 model year Land Cruiser, Toyota began using a new 4WD system called ActiveTrac. This same system was incorporated into all 2001 4Runners and the new 2001 Sequoias. The same basic system has also been used in the Mercedes M Class as well as post ‘99 Humvees.
**Same system, same name, though programmed specifiaclly for EACH vehicle model. It's the programming that varies the effectiveness and in the case of the 100 it's dialed in amazingly well, better than any other vehicle I have seen.**
These systems operate in essentially the same way with a few exceptions. When engaged, you have three open differentials working for you (front, rear and center). Open differentials are extremely reliable and require very little maintenance. If you have equal traction at all 4 wheels, power is evenly divided between them all. If one wheel begins to slip, the open differentials begin to send all available power to that one wheel. Normally, this would be very bad. This is when a traction control system (TRACS) takes over. TRACS, applies brakes selectively to a slipping wheel. This braking action literally fools the differentials into sending power everywhere except the slipping wheel.
When you are in 2WD (in the Sequoia and Runner), you still have traction control working for you. Obviously, this only will send power left to right but this is better than nothing. There is one thing to be careful of in this condition. When you are in 2-wheel drive, there is a second part of the TRACS that can be hazardous if you are not paying attention. This is the engine speed limiter. This combines the braking action of TRACS with a rev limiter. Your engine speed will be cut back to 1500 to 2400 RPM. This allows for controlled forward movement but it will be slow. The danger with this is if it engages when you are trying to pull into fast moving traffic. This rev limiter only operates in the 2WD mode, so if you know you have any reduced traction, make sure you are in 4WD.
**I have heard about this on the Seq and 4Runner though it's not the case on the 100. I can run idle to redline in 4-Hi or 4-Lo spinning all tires wildly (mud, ice, etc.) without the the throttle being cut back. In the 100 the only time the throttle will cut back is if your VSC activates (sensing a skid). This is not the case with TRAC in the 100.**
On all three vehicles, you have the option of locking the center differential. It is rare that anybody would ever need to do this. On the Land Cruiser and 4Runner, this is accomplished by pushing a button on your dash. On the Sequoia, you shift into 4 wheel low and shift the transmission into “L”. This turns off the TRACS computer and the VSC system. The vehicle is now in a conventional 4WD mode. All 4x4 Toyota trucks have operated in this condition. You should not ever use this mode on dry pavement as you will damage the drive system and tires.
**This is dead wrong. TRAC works in the 100 and the Runner/LX with the center locked. If it didn't it'd be useless.**
The other part of this system is the VSC or vehicle skid control. VSC will selectively apply brakes and throttle to prevent understeer or oversteer. It works in both 2 and 4 wheel drive. This is a rather amazing system and does an incredible job of giving the driver control of the vehicle. Understeer is responsible for a large number of SUV rollovers and oversteer is very common on icy surfaces. The Sequoia will allow you to turn off the VSC but only when you are in 4WD. The only reason to turn this off is if you are off road and want to be able to slide sideways. On the Runner and Land Cruiser, the VSC and TRACS are disabled when you lock the center differential.
**VSC yes, TRAC no. This souorce is wrong.**
The Land Cruiser is always in the 4WD mode. The 4Runner and Sequoia can be used in either 4WD or 2WD. It is safe to leave either in the 4WD mode at all times. You will loose a bit of fuel economy, but will handle better. Unexpected loose gravel and slippery surfaces will not be a problem.
To engage the 4WD system on the Runner and Sequoia, press the button. The green and amber lights will flash on you dash. While it is flashing, the system has not fully engaged and you should avoid sharp corners at this time. If you are accelerating up a hill, these lights will continue to flash. If this happens, take your foot off the gas for a moment and tap the brake. This gives the differential a chance to engage fully into the 4WD mode. The same procedure applies to disengaging the system.
To get into 4WD low, you must first be in 4WD. Stop the truck and place the transmission in neutral. Now, move the floor shifter forward to the low range. This takes a firm hand. This mode is only to be used to remove yourself from a very difficult situation. Once you are unstuck, shift back into the high gear range. "
I realize now that it was only referring to the Sequoia, and that was in 2001, so it has probably changed.
I definitely don't want to get into more discussion as to the differences between runners, sequoias, and LC's.
**You should get into more discussion. If you believe you posted source you're about to be duped into thinking your 2000+ you want to buy will not have TRAC when your 4-wheeling with the center locked.**
It does sound like the 2000+ LC is awesome. Thanks for lowering the resale of mine a couple of g's $$$$
I've owned my 4runner for 9 months and I think I once drove off my driveway into the grass, I think?? Never been in the snow yet (real mild winter so far) Just wondering what you knew? Guys on the 4runner site say good things about the off road ability, but who knows???
) have really come through on service info on my 80 ( 
). Kind of a 
