VSC Off in 2WD for V6 4Runners

[JonnieBlaze]

Is it common knowledge that grounding the ADD Actuator Detection switch and the Center Diff Lock Detection switch will trick the Skid Control ECU into turning off VSC, at least in my 2005 V6? I searched but couldn't find anything about the ADD switch specifically. There are many threads about the CDL switch.

Here are some threads discussing the grounding of pin 22 (red/blue wire) on connector B at the 4WD ECU, which gives V8 owners VSC off capability:
Toyota 120 Platforms Forum
http://www.toyota-4runner.org/engines-suspension-wheels-tires-audio-accessories/41357-vsc-off-atrac-mod-complete.html

It was found in these threads that this mod worked for V6 owners when they were in H4 mode, but not H2 mode unless they switched to H4 first, then enabled this VSC mod, then went back to H2. Somewhere in the first thread someone mentioned the ADD Actuator but the person who tested the theory said that grounding the ADD switch didn't change anything.

I've found that if I ground pin 18 (gray wire) on connector B at the 4WD ECU first (ADD Actuator Detection Switch), then ground pin 22 (Center Diff Lock Detection Switch), the Skid Control ECU turns off VSC without requiring me to ever go into H4.

Some questions I have:

• With the ADD switch grounded with my new button, if I switch into H4 from H2, will it cause issues? I’m afraid the 4WD ECU will think the ADD actuator is already activated so it won’t engage it and will instead only engage the transfer case.
• If I am able to make it into H4 without issues, and it goes ahead and engages the ADD Actuator, if I go back to H2 with my manual switch still on, will the 4WD ECU try to disengage the ADD? If it does it will never get a signal that the ADD is disengaged because my new button is acting as the ground. But I’m thinking the limiter switches inside the ADD will override and prevent the ADD motor from continuing to engage/disengage the ADD

Any thoughts how I can test these without causing damage?

 

[bassmacka]

It may be easier to just turn off the Traction control vai the mod than going through all this, but if it works it will be a bit cleaner.

 

[JonnieBlaze]

It may be easier to just turn off the Traction control vai the mod than going through all this, but if it works it will be a bit cleaner.

Yeah it would be cleaner in the sense that it's truly just a button push instead of a sequence you have to follow. Also there's nothing really extra to go through. Instead of grounding only the CDL, I'm also grounding the ADD. Putting a switch on the ADD is as simple as it was for the CDL.

I'm just looking for someone who knows the operation of this whole system well enough to help me understand if there's potential for damage doing it this way. Depending on the answer, it'll determine whether I also tap into the 4wd switch on the dash to disconnect my grounds when going from H2 to H4.

 

[bassmacka]

Yeah it would be cleaner in the sense that it's truly just a button push instead of a sequence you have to follow. Also there's nothing really extra to go through. Instead of grounding only the CDL, I'm also grounding the ADD. Putting a switch on the ADD is as simple as it was for the CDL.

I'm just looking for someone who knows the operation of this whole system well enough to help me understand if there's potential for damage doing it this way. Depending on the answer, it'll determine whether I also tap into the 4wd switch on the dash to disconnect my grounds when going from H2 to H4.

What would be the advantage of disabling the ADD. Correct me if im wrong but does that engage the lock with the center diff when you put it in 4wd?

 

[JonnieBlaze]

What would be the advantage of disabling the ADD. Correct me if im wrong but does that engage the lock with the center diff when you put it in 4wd?

The advanage of *enabling* the ADD (well technically just making it appear enabled) along with the CDL is so a single button push will disable VSC for those of us that have 4WD V6 4Runners. Otherwise we have to go through a process of going into H4 first, then the button, then back to H2.

I don't understand your second question.

Here's the process (simplified to only include the steps I've found that matter for VSC)

Factory way to turn off VSC:
- Currently in H2 mode - ADD disengaged, CDL disengaged
- Switch to H4 mode - ADD engages, TC shifts, CDL still disengaged
- Push CDL button - CDL engaged
* Result is VSC off in 4WD

The modded way to turn off VSC:
- Currently in H2 mode - ADD disengaged, CDL disengaged
- Switch to H4 mode - ADD engages, TC shifts, CDL still disengaged
- Push our VSC button mod - CDL engaged (not actually, but grounded the wire to make the ECU think it is)
- Switch to H2 mode - TC shifts, ADD attempts to disengage but can't complete (blinking green 4wd indicator), CDL still engaged (but again, not actually)
* Result is VSC off in 2WD

My thoughts:
- Currently in H2 mode - ADD disengaged, CDL disengaged
- Push our VSC button mod but with the addition of also grounding the ADD - ADD engages (not actually, just grounding the wire), CDL engages (not actually)
* Result is VSC off in 2WD

Refer to the attached for more detailed explanation of how the factory system works.

Hear me out that I'm not recommending anyone do this yet. I've done it and it works for me, but I don't know the implications of accidentally going into H4 or anything else with the button activated. That's the info I'm asking for help on.

 

[bassmacka]

The advanage of *enabling* the ADD (well technically just making it appear enabled) along with the CDL is so a single button push will disable VSC for those of us that have 4WD V6 4Runners. Otherwise we have to go through a process of going into H4 first, then the button, then back to H2.

I don't understand your second question.

Here's the process (simplified to only include the steps I've found that matter for VSC)

Factory way to turn off VSC:
- Currently in H2 mode - ADD disengaged, CDL disengaged
- Switch to H4 mode - ADD engages, TC shifts, CDL still disengaged
- Push CDL button - CDL engaged
* Result is VSC off in 4WD

The modded way to turn off VSC:
- Currently in H2 mode - ADD disengaged, CDL disengaged
- Switch to H4 mode - ADD engages, TC shifts, CDL still disengaged
- Push our VSC button mod - CDL engaged (not actually, but grounded the wire to make the ECU think it is)
- Switch to H2 mode - TC shifts, ADD attempts to disengage but can't complete (blinking green 4wd indicator), CDL still engaged (but again, not actually)
* Result is VSC off in 2WD

My thoughts:
- Currently in H2 mode - ADD disengaged, CDL disengaged
- Push our VSC button mod but with the addition of also grounding the ADD - ADD engages (not actually, just grounding the wire), CDL engages (not actually)
* Result is VSC off in 2WD

Refer to the attached for more detailed explanation of how the factory system works.

Hear me out that I'm not recommending anyone do this yet. I've done it and it works for me, but I don't know the implications of accidentally going into H4 or anything else with the button activated. That's the info I'm asking for help on.

On my 07 o can't turn off vsc so the mod isntonadd a switch that interrupts the power to the computer. It turns off vsc and abs. There is a YouTube vid I saw and I have been meaning to do it.

 

[JonnieBlaze]

So tonight I went out with a multimeter to watch what the 4WD ECU was actually trying to do with the ADD and Transfer case depending on the scenario.

I found that if we perform the sequence that's been outlined here and other forums to get VSC off in 2WD, the reason it works is because the ADD does not disengage when you go back to 2WD. So the process is you move the 4WD selector to H4, click your new VSC Off mod button, then go back to H2 mode. You've successfully tricked the Skid Control ECU into leaving VSC off. You have some annoying dash lights, but you're back in 2WD without the VSC system cutting your throttle. What actually happened when you went from H4 back to H2 is you left the ADD Actuator engaged. So now your front axles are still connected as you're going down the road or spinning donuts

So there are two things about that method that I don't like - the fact there's a sequence and not a simple push button, but also that the ADD actuator is engaged. I'm not sure if that leads to more wear and tear or what.

So then I added a new switch into the mix to also ground the ADD. Now you don't have to do the sequence to get into 2WD w/ VSC off and you aren't driving down the road with your front axles connected. You are truly in 2WD as Toyota intended it w/ the ADD disengaged, but with VSC off as we'd like.

I then watched the ADD motor and limiter switches and transfer case motors and limiter switches to see what happens if you leave those new grounding switches enabled while you go through the different 4WD modes. I found the only issue is again when going from H4 to H2, the ADD remains active and does not disengage. The same issue as using the currently recommended sequence I outlined above. So nothing negative necessarily, unless you don't want your front axles connected in 2WD. I did find that the lights on the dash were really confusing, but from what I could tell the Transfer case was still engaging and disengaging as you flipped the switch from H2 to H4 and vice versa. The limiter switches would change correctly each time.

So I think I'm comfortable adding the ADD ground into the mix and grounding it with the CDL. I doubt I'll leave the new switch on when going from H2 to H4 and back just to avoid those annoying confusing dash lights, but at least if I do, what I've looked at tonight has shown me nothing devastating will happen.

If anyone has any thoughts, or gives this a try and gets different results, I'd be interested to hear it. I only have access to my '05 so can't really test with anyone else.

 

[bassmacka]

https://www.youtube.com/watch?v=KBzlLqB-j-g This is what I was talking about I am pretty sure its just a switch.

 

[JonnieBlaze]

https://www.youtube.com/watch?v=KBzlLqB-j-g This is what I was talking about I am pretty sure its just a switch.

Yeah that's not the same one I'm talking about. That kills TRAC, VSC, and ABS. I'm talking about the mod I linked to and described in the first post....it only disables VSC but leaves TRAC and ABS activated.