Article By:
Rock Slide

Application Vehicle: 2001-2002 4Runner with VSC & TRAC Systems

The purpose of this mod is to show you how to install a rocker switch that will disable the VSC & TRAC systems with the push of a button.

Parts Required:

(1) On/Off rocker switch. I used an OEM, two-pronged, fog light switch. Toyota part# PT297-89013sw.
It?s about $10.00 from Toyota.
8' of 18 gauge automotive wire.
This is for two lengths between the switch and the master cylinder.
(2) female spade connectors to be used at the switch.
(2) barrel connectors, crimp-on style.
Or you may choose to use a soldering gun to secure the connections.
Electrical tape
Heat shrink tubing (optional)
Zip ties

Tools Needed:

Wire cutters
Wire stripper/crimper
Razor blade
Socket Wrench
Soldering gun (optional)

**WARNING**

If you have not worked on automotive wiring before, or are unsure of stripping, crimping, etc., please do not attempt this mod by your self.


**SPECIAL NOTE**

Before I begin, I would like to give complete credit to fellow YT member, aowRS for creating this mod.
The pictures I have included in this write-up and the majority of the instructions, if not all, belong to him.

I have simply taken his instructions and pictures from the many posts and threads on this subject and elaborated on them below; thus creating a formal write-up of the Andy Mod.

Any questions or comments on this mod should be directed to him. I can say I have since done this mod to my 4Runner and love it.
Thanks for all the hard work in figuring out this mod Andreas!

Step 1:

I made a wiring harness using the rocker switch, spade connectors, and wiring.
The actual distance from where the switch mounts to where you will tie in to the ground wire is very short.
I just used two 4' lengths of wire to make sure I had plenty of slack and also to make feeding it through the firewall grommet easier.

If you insert your wires through the firewall grommet, be careful not to pierce the grommet itself when inserting the wires through it.
I did and when ever it rained, water rolled off my hood onto these wires and ran right into the cab of my 4Runner causing the carpet to mildew!
Took me forever to find out how water was entering my cab.
You may want to think about drilling a new hole and run the wires through that and waterproof it accordingly, or stick with the existing firewall grommet, but be sure after you are done to coat the wires at the grommet with a lot of black silicone to prevent water from entering.
I did this on the engine bay side and cab side to make sure I did not have any more leaking problems.
Problem solved.

If you go this route, you can choose to heat shrink the spade connectors and the wire, or use electrical tape.
Others have tried using a 3-prong switch with no luck.
I have found this mod works great with the OEM 2-prong rocker switch.



Step 2:

Once you have the 'harness' made, take it and the barrel connectors to the truck.
Before doing any electrical work on your 4Runner, disconnect the battery (socket wrench).

Pop one of the remaining factory switch blanks out and insert your harness into the void.
It may help to pop the fuse access panel off.
From there you will need to get the two wires through the firewall grommet (directly below the master cylinder).
I found that inserting a long zip tie through the grommet from within the engine compartment was sufficient to use as a 'fish' tool.
I then took my two wires from the switch and taped them to that same zip tie inside the vehicle.
Now go back to the engine compartment and carefully pull the zip tie out with your 2 new wires attached.

Once you have pulled the wires through the grommet, check to see if they come in contact with any sharp edges under the dash and throw away the ?fishing? zip tie tool.
In my case, I routed them cleanly and then zip tied them on to existing wire bundles.

Step 3:

Now you are ready to identify and cut the correct wire at the master cylinder. Pull the pressure sensor connector out from the master cylinder and undo any tape that keeps it bound to the other harnesses.



You will see red, black, and white wires right at the connector.
The red wire is the ground wire and is used for this modification.
Rather than spend 10 minutes explaining how to expose the wire, I'll just state that you will need to make your splice a few inches back from the connector.

Carefully open up the black plastic covering and then the gray shielding that covers the three wires (razor blade).
When you have exposed the wires enough, you will need to cut the red wire in half.

Now you have two options:

1. You can choose to use crimp-on barrel connectors to attach your new wires to each of the exposed ends of the previously cut red wire.

Or

2. For a more secure connection, you can solder your new wires to the exposed ends of the previously cut red wire.

If you choose Option 1, make sure to crimp your connectors properly.
I have seen others who have done Option 1, and the crimping action actually broke the fine wire, thus giving them intermittent results. .

I chose Option 2.
To do so, simply take one of your new wires and solder it to one of the exposed ends of the previously cut red wire.
Next, take your other new wire and solder it to the other exposed end of the previously cut red wire.
It does NOT matter which of the 2 new wires you solder to the red wires.
All you are doing is adding a longer connection to the pressure sensor connector via your 2 new wires.
The switch itself, when turned on, is what breaks the current to disable VSC & TRAC systems.

Once your harness is spliced in and covered (tape or heat shrink), you will want to get everything wrapped again properly. At this point you are almost done.

Step 4:

I situated my rocker switch so that the bottom half is pressed in when it is in the off position.
This matches the orientation of my two other rocker switches.
If you find later that it is reversed, you can simply switch the connectors on the back of the switch (see Step 5).

For what its worth, I made my own "TRAC OFF" label by scanning the factory TRAC OFF switch, darkening the image, and printing it on a standard mailing label.
A few coats of satin polyurethane spray on the actual rocker portion, and it turned out nice.



Step 5:

Reconnect your battery.
Plug the pressure connector into the master cylinder and start your truck.

Now, one of two outcomes will happen:

1. After you have started your truck and the ABS, TRAC & VSC lights all light up on the dash (might take a couple seconds), then the switch is in the "ON" position and working properly.
You have interrupted the ground for the pressure sensor connector and can operate the truck without any TRAC or VSC intervention!
You are now able disable TRAC & VSC while in ?Park? or on the fly.

2. If you start your truck and the ABS, TRAC & VSC lights DO NOT all light up on the dash, then the switch is in the "OFF" position.
Simply flip the switch and the ABS, TRAC & VSC lights should all come on.
If you find that your switch is reversed than what you would like to be, pull the switch out and switch the connectors on the back of the switch.

I wish it were as easy as flipping the switch to turn VSC & TRAC back on, but it?s not.
First, flip the switch to the ?Off? position and then turn your truck off.
Now restart your truck and all the systems should be back online.
Hence TRAC & VSC are working properly.

Since the system only needs to sense a break in the ground wire to cause a shutdown, you can also flip the switch ON, wait a few seconds, and then flip it back OFF.
TRAC & VSC will remain shut down (until you restart your truck), but this might help you remember the switch is OFF when you turn your truck off.

Enjoy the benefits of disabling TRAC & VSC!

Any questions about this article, please contact aowRS, and not Writeups@YotaTech