About to do the VSC disable mod....help?

[jgmx893]

So I'm about to do the VSC disable mod (CJFlyr's: http://www.toyota-4runner.org/engin...ories/41357-vsc-off-atrac-mod-complete-2.html).
I'm kind of confused as to why people are grounding the wire. Any reason why not to just make a break in it and put a switch in? I've heard that if you do this then the center diff lock light won't come on. I'm just thinking here, someone provide some insight before I possibly screw something up lol.

 

[DC runner]

In this situation, the ground is acting as a negative return ground. Not connecting it breaks the circuit for the indicator and potentially other issues.

In general, electronics behave much better with a reliable ground. I won't bore you with a long electrical training session, but if you really are about to intentionally mess with the wiring of a very complex car that people with Ph.d's in electrical engineering designed, you should wander over to "how things work" and take a look.

A faulty or disconnected ground can cause ALL manner of nasty things. Over Amp Pull, causing burnout. Voltage drop causing faulty electronic problems.

Anyway, hope that helps.

 

[jgmx893]

Yea that helped to think of it as a return ground opposed to the switch just "blocking out the signal" as I was trying to think of it. And I'm well aware of how wrong things could go, first thing I'm doing is going to be to make sure it's actually grounding it well.

 

[BlackWorksInc]

In this situation, the ground is acting as a negative return ground. Not connecting it breaks the circuit for the indicator and potentially other issues.

In general, electronics behave much better with a reliable ground. I won't bore you with a long electrical training session, but if you really are about to intentionally mess with the wiring of a very complex car that people with Ph.d's in electrical engineering designed, you should wander over to "how things work" and take a look.

A faulty or disconnected ground can cause ALL manner of nasty things. Over Amp Pull, causing burnout. Voltage drop causing faulty electronic problems.

Anyway, hope that helps.

Awww you're no fun! Maybe some of use want to hear the boring stuff! Or just see if you'll waste hours typing that all up for no one to read like I do!

 

[robtmc]

Any reason why not to just make a break in it and put a switch in?

If you are doing the basic VSC defeat by fooling the VSC ECU into thinking the CDL is on, all you are doing in pulling a signal line to ground. In digital signaling, this is a reliable and foolproof method. Ground is ground, not 0.1V, not 0.5V, but 0.0V. That is why is it used in modern digital work so much.

All this mod does is pull the VSC ECU pin #27 to ground, same as the 4WD ECU (or switch box) does if you were to select CDL LOCK.

I am doing it with relays to mimic a factory pushbutton switch type action, that also is shut off when the ignition is shut off. It is probably more involved than other than electronic hobby types would want to bother with.

There is the more dramatic VSC and TRAC and everything mod that does cut the brake fluid level sensor line. That is a different animal, not what CJFlyr or I are talking about.