Yellow wire mod or what the heck is happening?

OK, what did the previous owner do to this 2014 truck? He installed a little on off switch in one of the plug holes on the dash. I’ve switched it off and on a couple times but couldn’t figure out what it was for. Finally, yesterday I took it out off-road for just a little cruise and I noticed that the 4lo light was blinking but there was no warning buzzer and the transfer case did engage 4lo. I thought it felt like the front axle was not engaged but I wasn’t entirely sure. I will also add in 4hi the front tires did slip on sharp corners so I know the front axle does in fact engage in 4hi. I did notice that the rear tires slipped a lot when I was turning sharp in 4lo, but it didn’t seem like the fronts did. After thinking about it I thought maybe he did the YWM.



Fast forward to today and I thought maybe I’d look behind the glove box and see if I could figure out if this had the YWM. When I got the glove box out I saw two wires leading over toward that area, so I thought he set it up to turn on and odd via the dash…sounds sweet so far. So yesterday the switch was on because that’s where I left it last time I messed with it. Now I’m thinking I’m good to go, except of course I’ve heard the mod does not work on the 2014s. I jump in the truck switch it into 4 low and the 4lo light still blinks. I then turn off the little dash switch and the trac control, and vsc light both light up and the 4lo stops blinking and holds steady.



Does anybody have any insight as to what I’ve got going on here?

 

Maybe a 2lo mod from @Up2NoGood ??

 

That is odd... I have no idea..

 

Doesn’t sound quite like mine but maybe a DIY version of 2lo mod

 

Maybe I need to get one more set of jack stands and see what happens. I'm just excited to finally figure out that the switch does something.

 

One more question. Is there some kind of advantage of having the trac and vsc lights lite up while off-roading in 4lo? I haven't put her up on jack stands yet, but I'm pretty sure the front axle is engaged when the dash switch is on and the trac and vsc lights are lite by this switch.

 

Maybe call the previous owner and ask him? That’s what I’d do.

 

I'm the 3rd owner and the second owner bought it as a certified pre owned from a dealership. The second owner was NOT a truck guy and knew nothing about the regular cabs. He thought the truck was pretty much stock except for the tires.

 

Well, never mind then.....

 

It's all good.

 

It disables the traction control and vsc mod
I think it's in this thread.
https://www.tacomaworld.com/threads/need-help-with-turning-off-abs-vsc-trac-mod.352604/

 

@David K

Cant remember your threads name

 

Can it be "certified" with diy mods like that? Feels like a warranty buster.

 

I don't know what "yellow wire mod" means, but what he did, is he added a bypass that prevents the "low range" mode signal from being sent from the 4WD ECU to the SKID CONTROL ECU. This has the effect of allowing the skid control functions to continue operating WHILE the vehicle is in low range, which normally is not permitted.

 

So in other words it will limit the throttle and add braking to avoid a spinning wheel in 4lo?

 

No. It will add braking. It won't touch the throttle.

 

Is it the one in my signature links? I have a few!
My truck is basically stock so my info is not about mods but only about what the stock settings do or how to operate them.

I do recall from the Yellow Wire Mod posts that the 4LO blinking is normal when the TRAC is on, and of course solid when it is normal without TRAC. Double check my memory.

TRAC is a limited slip and only available on 2nd Gen in H2 and H4. Before 2012, TRAC in H4 had no engine regulation, only braking for more wheel power. The mod made this available in L4, a benefit for those who did not buy the Off-Road and have A-TRAC.

 

I know. I believe it was the one with all the lsd and traction button control section, where you where talking about holding the button and what not.

 

Here is the latest one: https://www.tacomaworld.com/threads...lsd-trac-off-vsc-off-a-trac-rr-locker.577229/