Multimode to J-Shift Transfercase Swap

[nateboor]

Hello,

I am currently in the final stages of 5-speed swapping my 2001 limited. It starts just fine, but I am working on diagnosing as to why my 4wd light is flashing and my VSC OFF and VSC TRAC lights are on, among the expected CEL. I have read the following thread multiple times, but am still a bit fuzzy on the details, not to mention his is a different year:
Multimode transfer case to standard J-shift

I am hoping someone with a bit more electrical prowess and understanding of what wiring I am going up against can help.

Ps. Please spare me questions as to why I am swapping tcases. Thanks.

 

[Doc2012]

Does your 4wd engage, or no?


Sent from my iPhone using Tapatalk

 

[Malcolm99]

I haven't done a manual swap on a 4R, and haven't seen 01-02 manual trans and manual tcase swaps done on 01-02 so not much help but a few things jump to mind.

Are you using your 2001 ecu and harness and repined it?. Or did you go with the 03-04 Taco ecu and harness, I don't think the taco 4x4 came with vsc unless requested.

Doesn't the 2001 have a different 4wd ecu's and abs ecu's that control trac and vsc and the other controls tcase positions, wouldn't you need the jshift 4x4 ecu wired in place accordingly, and have to unplug the Trac and vsc bulbs as they would no longer function, I think they use inputs for tcase position to operate vsc and abs.

Just thinking out loud as that sounds like a difficult swap but interesting.

 

[Team_Jake]

Is there are reason you are switching to a J-Shift transfer case? I kept my multi-mode transfer case in my '99 Limited after my 5-speed swap and have had zero issues.

 

[Malcolm99]

Only reason I can think of is if he plans to add a crawler box in the future, I think the multimode takes up to much space to add that, but he doesn't want to provide many details of his swap or discuss reasoning,.. otherwise it would be ideal to have multimode 4wd/4x4 on a standard I would think, although a lot more electronics that could potentially fail, never had a problem with my 99 multi mode though, but I use it and RRDIFFLOCK monthly the past 8 years of ownership. Again not my wheelhouse, Tyler James and a few other have lots details but went with the original multimode on a 01-02, I noticed all the pics of details have disappeared though which is disappointing.

 

[toyotaspeed90]

Well the VSC would be inside the transfercase, so swapping an earlier J shift wouldn't have one.

I swapped my 97 from multimodal to J shift because it was year to year, I had no idea how or if the multi mode works (though assumed it did) and REALLY liked the J shift I pulled from the 97 SR5.

At least on a 97 -there isn't a computer for the Jshift, just a set of ADD relays - which the limited has as well but receives a signal from the 4wd ecu. The 4wd ecu is really only looking for ground signals so tricking it with a J shift is about as easy as witing gets.

 

[Malcolm99]

I don't think the VSC is inside the tcase, but again I'm not well versed in 01-02 or this swap, I figured the vsc was controlled by the abs/vsc/vss/yaw/pitch ecu and 4wd ecu to apply brake to whichever wheel they deemed ideal according to data to correct for yaw/pitch/wheel spin and maybe cut throttle position( maybe not this early on quite yet? Or maybe 01-02 was the test dummy for this system now widely used by Toyota) and trac operates the same but is just using the abs sensors for wheel slippage applying brake at that wheel, they don't have an intelligent tcase that sends power differently front or rear afaik but haven't worked on one like this exact truck. On the 2nd Gen 2011 Taco my dad has, all traction, vsc, uphill/downhill assist, atrac all use and abs sensors to apply brakes at whichever wheel and cut throttle to counter wheel slippage(atrac) or yaw/pitch(VSC), I'm glad you can disable it in the 2nd gen Taco by pushing and holding traction control button or using RRDIFFLOCK, but I'm not the guy to ask, just a guess, never wanted to dig into it as long as its equipped and works

 

[toyotaspeed90]

Sorry... VSC is stability control.... was thinking about a viscous coupler (which the full time 4wd Landcruisers have in their transfercase... and my brain was thinking about the multimode may have done something different for 4wd high).... my mistake.

 

[Malcolm99]

Viscous Coupler in a Toyota tcase, interesting, I have a VC in the rear diff on my car, didn't know they used that in a Yota tcase, I thought it was a Torsen centre diff in the newer tacos and a lockable centre diff in multi mode Toyotas or full time 4wd sequoias and landcrusiers.

 

[toyotaspeed90]

Viscous Coupler in a Toyota tcase, interesting, I have a VC in the rear diff on my car, didn't know they used that in a Yota tcase, I thought it was a Torsen centre diff in the newer tacos and a lockable centre diff in multi mode Toyotas or full time 4wd sequoias and landcrusiers.

Since 1991 the Landcruisers in the US have been full time 4wd. There's only high and low selections. The CDL engages in low (there are ways to bypass and lock it in high, but not from the factory) at which point power is locked to provide to front and rear. In normal driving there needs to be a typical method in which power can transfer between wheels and, essentially, can also act like an open diff allowing wheels to turn at different rates. Well, the way to overcome this in, say, snow driving nog requiring low range- was a viscous coupler in the transfercase.

Things got weird in the later 80 series as they started to add nannies but kept the coupler. If I recall reading right, my old 01 LX had both ATRAC and a viscous coupler.


Begs the question if there's something in the later years 3rd gens that have atrac...