2LO Plug & Play Harness Discussion

On my end all the wire needs to get cut and stripped. On your end, nothing needs to be done.

There is a link to the thread by @BigWhiteTRD with a pdf writeup. If you read through that and where you start cutting and splicing wires, ignore it. Unplug the two connectors from the 4x4 ECU, plug in the harness, tape/zip tie the relay somewhere, install the switch in your chosen location, run the switch wire, and put everything back together. It is literally plug and play.

 

Here is a crappy video of going in and out of 2Low.

Order of things I did in the video.
1. Push the button. (on)
2. Move selector to 4Hi and wait for it to engage. (I had to drive forward a few feet and turn the steering wheel to get it to line up)
3. Move selector to 4Low (wait for it to engage. I have the MT so the truck beeped at me until I pushed in the clutch.)
4. You are in 2WD low range. HORAY!

5. Push the button again. (off)
6. Shift to 4Hi, then to 2Hi and wait for everything to disengage.

I also showed normal 4HI and 4Low engagement at the end. I realize you can't see that it's in 2Low in the video, but trust me it is. Yesterday I pulled up the hill on the left (my yard covered in about 4" of wet heavy snow) and spun the back tires on the pavement. The front tires didn't do a damn thing.

Yes, my seatbelt is not on, no my door is not a jar.

 

I don't mean to over think this, but I'm just going over some potential scenarios.
With the button activated, will 4HI basically just be 2HI?
If so, could a guy just leave the button active all the time in 4HI, (giving 2HI range), then just flip down to low range for parking or low speed maneuvering with a trailer?
Would there be any ill affects of leaving the button active while in true 2HI range?

 

You could do that, but what that means is the driveshaft exiting the front of your transfer case will always be spinning. It is extra wear and tear on those components, including your T-case. I'm sure there is something else to do with stability control or a-trac that would be affected too. I would not recommend doing this.

 

How are things progressing?

 

I'm finally back in the office tomorrow. I have my harness removed and wire lengths figured out. I'm going to drop it off to get the labor quoted tomorrow.

 

Awesome

 

Also, to keep this easy.... Wiring for the switch will be the same length regardless of where you want to locate it. Left of steering wheel, center, or overhead console. There is plenty of room to the right or above the glove box to neatly coil up and zip tie any excess wire. I will be providing the switch wiring with the correct plug termination for the two available custom switches. Still waiting to see if the 2nd place can get switches with the lighter blue to decide if I will include the switch or not.

 

I just wanted to let everyone know that this isn't dead, and far from it.

Dealing with vendors is a pain in the ass sometimes. I have drawn up a schematic/wiring diagram, made a harness layout with dimensions, and a BOM with all the correct part numbers to get this thing quoted. I have it out at half a dozen places now, but most of them requested a "sample" for when they do start producing them. I have ordered some more components to build up a "sample". Until I hear back from a couple of them I won't have a final cost.

 

Any updates?

 

I have a quote that looks good and I will be sending out my 2nd prototype to get a couple production samples made. If they look good I will be able to start taking orders. Once I have looked over the samples I will have pricing info for everyone. I think everyone will be happy with the final pricing. Keep in mind, this is all going to take at least a few weeks to get done with shipping and all.

Sorry this is taking so long. Everything is still moving along, it is just taking more time than I would like it to. I'm also hesitant to get a large batch of these made up if Mat @OVTune can do something in software. I don't want to have a ton of $ tied up in these if the demand trails off.

 

Cool. Thanks - I wasn't pushing you to hurry... I was just looking to hear it was still alive.

I, for one, do not consider an $800 payout to OVTune as an option to what is available and practically free if you cut your own wires. I'm glad to pay for the nice clean install but not the better part of a grand

 

Badass. So ready to put this in with the rest I have going this spring. I even already got a switch for it when I ordered the rest of em......

 

That's pretty much what I figured. There are a bunch of people that already have the tune, but there are going to be others that have no interest in spending that kind of $$ on it.

 

2wd low will be fantastic for the super high reverse gear on the MT when backing up a trailer.

 

Not saying Matt can't do it, but I think it is exceedingly unlikely that he implements 2Lo for technical and other reasons thru tune. Especially as its located in the completely separate 4wd ECU.
(I think he probably won't be doing locker mods, and think 2Lo changes are so far lower than that as to be ridiculous).

Really, only a more computerized 2Lo solution that uses the existing dashboard dial (or similar) would be the only possible reasonably expected competition.

Can probably sell some customized ones to people to allow actuator emergency override, and a few for customized for FJ swapouts, etc...

I know it's hard to pull the trigger and risk holding the bag.

 

I agree it is highly unlikely to see a software option. Like you said, it appears the 4x4 ecu has full control and likely only notifies the ECU of status and faults. It's not like on my VW where you can access each module directly and change coding to get different functionality. Vw dealers have that option with their Diagnostics, but Techstream is much more limited.

A computerized 2lo solution would probably be cost prohibitive. I honestly don't see the advantage of that over your relay method. It would still be doing basically the same thing, but add complexity. It would gain some factor of idiot proofing I guess.

 

ANy chance you’d do a similar mod for an anytime locker?

 

Here is the thread for that discussion

https://www.tacomaworld.com/threads/rear-diff-lock-anytime-mod-3rd-gen-development.537810/

 

If you take a look at the thread started by @BigWhiteTRD the possibility of doing a nice PnP harness is pretty much nil.

https://www.tacomaworld.com/threads...-gen-development.537810/page-15#post-20158538

The TLDR version is, in order to disable ESC and ABS with the locker manually engaged, you would need to splice into the ABS computer harness in the engine bay. It is possible to engage the locker without doing that, but I'm not willing to put my name on something that does it. I'm also not willing to tell people to cut into factory wiring for that system. All the info is in the thread if you want to try for yourself. I can give you the part numbers and source for the connectors you would need.