GX470 4WD and Traction Control Question

[JSparky]

Hey everyone, I'm here to try and find out some info for a friend who just bought a 2003 Gx470. As far as I know it uses the same full-time 4wd as the limited 4Runners.

My question is how does the VSC and/or ATRAC operate with these trucks? There is no ATRAC button that I can see. I reviewed the owners manual and it states that with the center diff unlocked VSC remains on, with the center diff locked the vehicle's VSC turns off, regardless of hi/low range. This seems a little odd to me but perhaps it's to allow torque transfer front to rear, so I could see that. Either way, is what's stated as VSC in these trucks equivalent to ATRAC? Or do these trucks lack ATRAC altogether? In my 5th gen trail edition I believe I had VSC in high range, in low range it would turn off (part time transfer case) and I had a button to turn ATRAC on or off when in low range.

I searched for awhile online and couldn't come up with anything, any help understanding the full-time 4wd is appreciated. Thanks everyone.

 

[JSparky]

Ok. Best I can tell is VSC is entirely independent which is what I thought. ATRAC in these trucks is on all the time. With the center diff locked VSC turns off but ATRAC remains on. This sound right? Sorry if this is obvious for many of you, just trying to get a hard answer to how all these systems interact. My 5th gen had a button so the lack of one is confounding.

 

[Inv4drZm]

Yes, this sounds correct. ATRAC does have an RPM limit to keep in mind, I don't remember off the top of my head the exact figure.

 

[Drunner97]

Yes, this sounds correct. ATRAC does have an RPM limit to keep in mind, I don't remember off the top of my head the exact figure.

I want to say I've seen under 2k rpm for best results, once you go over it's less aggressive.

 

[techno]

Ok. Best I can tell is VSC is entirely independent which is what I thought...

Yeah, sort of. Both systems use the same electro-mechanical hardware, but for different purposes. ATRAC is for traction control and VSC is to keep the vehicle stable and reduce rollover type things.

 

[JB.]

Ok. Best I can tell is VSC is entirely independent which is what I thought. ATRAC in these trucks is on all the time. With the center diff locked VSC turns off but ATRAC remains on. This sound right? Sorry if this is obvious for many of you, just trying to get a hard answer to how all these systems interact. My 5th gen had a button so the lack of one is confounding.

Yes.

I try to avoid the acronyms and phrases as their meaning has changed over time. The meaning of ATRAC is not the same in the 4th and 5th gen 4runners.

So, in descriptive language -- in the 4th gen (and presumably the Lexus) with center diff locked the brakes will pulse to control wheel spin related to lost traction but the engine will not de-throttle.

Imagine a 5th gen LE without an ATRAC button, terrain/crawl controls or mandatory locking of the center diff in low range.