3rd Gen Spoofer Development for ADD and Transfer Case Actuators

The manual T-Case replaces the Automatic T-case (sometimes called FJ-T-Case-Swap). The manual T-case has indicator switches you wire up to the automatic T-case T4 plug to indicate when you have shifted into 4WD-Hi and 4WD-Lo. Right now I can use full 2WD (Hi/Lo) and 4WD (Hi/Lo) with ADD and anytime rear elocker. I just want to see if I can get the 4WD ECU spoofed so everything is working to use Toyota's other Offroad options like traction control etc...

If you have a Toyota elocker on a 3rd Gen you can do an anytime rear elocker using the Eaton Elocker Universal wire harness. That is what I have done and it works perfectly other than the 4WD ECU not being happy about it. I am not using the stock rear elocker button, instead I have the universal wire harness connected to an 8-gange switch panel. I do not want to do ARB air lockers for my own reasons, but done right they are great lockers.

 

I wasn't aware of this, thank you. I must have been remembering the 2nd gen modification.

 

@rmack
Are you saying you found both the Male and Female connectors for T4 (xcase connector)? If so, could you please share.

I made up a cable extension (9"-12") for the addition of a crawl box between the AT and the xcase. This was done by unpinning the 9 contacts of the 12-contact female connector(T4) and reinserting them into female 4-contact and 5-contact connector. My pigtail has the Male 4 & 5 contact connectors at one end and the original female 12-contact connector at the other end.

I was unable to find the male 12-contact connector that resides on the xcase.

Its late go to bed and answer in the morning.

 

@Toycoma2021 - no unfortunately I didn't find one. I looked everywhere I could think of... Instead I cut each wire one by one from the T4 line and used a new adapter (https://a.co/d/6oRU9Q6) to connect them all back. I made sure to cut far enough back so I could reuse the original plug and connect it to my new connector if for any reason I wanted to use an automatic T-case again.

Note: I wired them all back the same with the new 12 pin connector. If I need to I can buy the same connector and mate it to the original connector and go back the auto-T-case

 

Under the truck ...

 

Dang, thought you might have solved a sourcing problem. Oh, well.

If your project goes into production, I would suggest for simplicity's sake finding compatible connectors to the 12-contact (in a format that is not 12) and forgo the cutting and just move pins around where need be making it all reversable. This would make it a bit easier for those not so inclined to "cutting" up their wiring. Sumitomo connectors iirc.

 

OK, need to go to bed soon...

I found this which looks just like the T4 plug .... "1JZ Non-VVTI Ignitor Connector" and when searching for the male side I found this ...

https://www.wiringspecialties.com/copy-of-1jz-non-vvti-ignitor-connector/

Everything looks right, but I don't know the size ... I would have to order one to figure out if it would work.

Search for "1JZ Non-VVTI Ignitor Connector" and you will see it looks pretty much identical. Only the Wiring specialties place has the male that I could find, but hey maybe this will work for you? It does cost $41 .... maybe if it works piece of mind for not cutting wires?

 

$41 dollars for the Male connector - no way. Even if it is the correct one. Their female connector was $16. They must know what they have and want real money for it.

I will have to go through the Wiring Specialties web site sometime to see what they have of interest. My impression of the site so far was of another site I found that catered to those people/mechanics that were desperate to get the right part the first time for their customer. Despite the cost.

I am not cutting wires, but de-pinning the connector and putting the pins into other, compatible connectors. Very reversable. Connectors come in families with different number of cavities, all taking the same pins or contacts.

Have you seen these suppliers?:
Sumitomo Motorsport Connectors - Corsa Technic good prices and availability

Ballenger Motorsports - High Performance Electronics

自動車用部品:Sumitomo Wiring Systems, Ltd company website

tss.pdf Sumitomo pdf catalog for one family.

SUMITOMO Products - OCO Connectors

Connectors | Yazaki North America not for this project.

 

T-case spoofing latest status. I found one major issue with the 2-Relay design for just spoofing the T-case part. I will need to add in 2 diodes into the solution. Once I am done adding these in and testing I will post my next status.

 

Continuation of post #68 showing the transfer case extension cable for the future crawl box.

 

Latest status ...

Summary based on information below:

• Diodes wired up works to prevent Pin 1 F13 from being grounded
• 4WD F13 wire harness plug reconnected throws code and dash lights (error)
• Still haven't tried shifting due to 4WD F13 wire harness plug issue
• Rear elocker original plug still in over anytime locker harness as the elocker will also need to be spoofed

Latest status ... investigations... Actions and Observations details

Old action still in place, remove observations based on new Action-4

• Action-1: Disconnect T4 Wire harness from T-Case AND Disconnect Pin 1 from Relay 2 & 3 (4WD & ADD)
  • Note: All relays should be in default 2WD condition

• Action-3 w/ action-1: Disconnect Truck F13 Wire harness from T-Harness but keep T-harness w/ relays etc... connected to the 4WD ECU.
  • Note: No connection coming from Truck T4/ADD plus etc F13 wire harness plug

Slimming down possible issues to investigate:

• Why-1 is Pin 1 F13 that is not attached to anything on the Truck only the T-Harness (Relays) and 4WD ECU grounded?

• Hypothesis: Pin 14 on F13 coming off of both Relay-2 Pin 87 and 87a grounding other circuits
• Experiment: Add diodes from Relay-2 Pin 87 and 87a on Pin 14 going to F13
• See Action-4 below

​

• Why-2 does connecting the Truck F13 wire harness to the T-harness make the ECU throw codes?

• Action-4 w/ action-1 & action-3: Diodes wired up inline with Pin 14 on F13 coming off of both Relay-2 Pin 87 and 87a
  • Note: All relays should be in default 2WD condition
  • Observation: Pin 1 F13 (4WD-Hi) NO longer grounded
  • Observation: Truck power on with 4-Lo dash light OFF and NO error code thrown
  • Observation: Relays get power
  • Observation: Hypothesis correct with why-1, diodes do in fact fix grounding of Pin 1 F13

• Action-5 w/ action-1: Reconnect 4WD F13 wire harness plug into T-Harness, so remove action-3

• Note: All relays should be in default 2WD condition
• Observation: Truck power on with 4-Lo dash light ON and error code thrown
• Observation: Relays get power
• Observation: Why-2 problem not solved, with no further investigation yet.

​

 

Latest status as of today.

• When powering on the truck with the truck F13 wire harness not plugged into the T-Harness no codes no dash lights default mode 2WD (appears to work)
  
  • When trying to energize the 4WD-Hi relay to turn on 4WD-Hi but it doesn't go into 4WD-Hi - nothing appears to happen (no dash lights no codes thrown, nothing appears to change)
• When powering on the truck with the truck F13 wire harness plugged in the 4Lo and 4WD lights blink ...

I need to take a break from diagnosing so I can weld in my new support for the crawl box (works without, but I want it in) and I need to prepare for a wheeling trip this weekend. Will try again on Sunday.

 

I have been a bit busy, still planning on trying some extra stuff, but right now what I have isn't working right. I don't think it is the circuit design, I think something else is wrong with the truck.

Here is the 2 relay setup I came up with to spoof everything so far. I might make updates, but just in case anyone else wanted to try it.



Here is the design for the ADD, credit goes to @BLtheP on this one.

 

With an FJ case swap on a 3rd gen Tacoma.
If one did not care about dash lights working (4wd or 4lo) but wanted to keep the 4wd ECU happy so the e-locker works with an anytime locker system. Could the transfer case actuator just be removed from the original TF case and left plugged in elsewhere? Assuming the timing of actuator was set correctly. All the sensors are in the ADD and TF case actuator that communicate with the 4wd ECU as far as I am aware.
I have personally removed my ADD from the front diff and moved it to a safe place out of the way of water etc.. I replaced it with a solid shaft from a Lexus GX470.

 

Yes, a lot of people already do that with the actuators tied up somewhere plugged in. My goal was to try to be able to get away without doing that for those swapping.

 

As @BLtheP mentioned ... but I also don't want that thing in my truck if I don't need it. Also you can simply install a new wire harness to get the rear elocker going as an anytime elocker. The information @BLtheP posted should work, the 2 relay system I came up should work. I just need to figure out what else is wrong with my system. I have other projects going on, but I will be coming back to this one.

 

good read.

i recently had some issues with what i thought was my ADD. turns out is was actually the sensors in the servo on the diff.
well it sent me down a rabit hole and i now have an FJ transfer case with twin sticks in my garage and a taco box.

i'm a huge advocate of keeping factory electronics working with any modifiactions that i do, so i had developed an excell sheet with wiring and i was going to just use an arduino to trick the dash lighst. i figured out with the help of this forum that when shifting into 4, the transfer actually engages first and then the ADD up front switches over, which is why we can shift while moving. Toyotas trouble shooting guide tells you what reading the ECU is supposed to be seeing when in 2H/4H/4L, which made me belive that i could run the FJ case without having to keep the ADD permanently engaged as mentioned. i actually want to keep that feature just because of the way i use the truck and i like being able to swap to 4 while doing 45 and jump onto a dirt road without stopping.

not having parts in the truck yet, my goal was to use the t case sticks and sensors to imitate the knob on the console, like the FJ already does. use the signal for 4H/4L the same way turning the knob does. go through the arduino to send the signals to the 4WD ecu, which would have the dash lights reflect the current driving configuration. mainly because of all the traction control, abs bla bla bla lights that would be on/off when in 4. an arduino nano every is currently $38 for a 3 pack. i can make it do everthing in maybe 15-20 lines of code while taking a dump.

but, reading through here, im confident this can be done without a micro controller.

i did not read every single post on here in depth, but if it wasnt mentioned, this would definitley be a hot seller if it was mas produced as a plug and play setup for a trasnfer case swap.

 

Hello @Boost4brains - you don't need a microcontroller to kick the signals to the 4WD ECU you can use a 5 pin relay(s). I also came up with a microcontroller solution, but running the relays initially to figure stuff out was easier.

Note: first I haven't finished debugging my wire harness as I have been super busy with other projects. When I was last working on it it appeared tracing all of the wires that all of the signals from all of the relay(s) were working as @BLtheP and I have discussed. But I have a few other issues that I think I need to fix before I can finish up testing my wire harness. With this I haven't started this back up yet. I.e. Steering stabilizer sensor, and one other item. I hypothesize that these need to be fixed for me to work on the 4WD ECU spoofer. @BLtheP indicated with his initial testing things seemed to work.

With my setups I have everything on separate wire harnesses.

• ADD is on a separate/independent wire harness - https://www.12thstateoffroad.com/product/add-actuator-harness
• I have my rear Toyota e-locker on it own wire harness - "Eaton 23249 / 915911 E-Locker Universal Wiring Harness Kit"
• I wired the T-Case indicator switches up and connected them to the factor wire harness to the 4WD ECU.

I am able to shift into 4WD-Hi up to 60ish usually only do this up to 40mph.
I am able to turn the ADD on after shifting into 4WD-Hi right after
The new anytime rear locker I only turn on when I am not moving

The ADD wire harness was easy to setup and works great with no issues. The eaton universal wire harness works great with no issues for my 2022 TRD-Off road OEM e-locker.

I have no issues with using this setup. I actually prefer it. So I can use manual 4WD-Hi, 4WD-Lo, and 4WD-Lo-Lo. I can also use the rear locker in 4WD or 2WD, and I can use 2WD in Lo-Lo.

With all of this working what isn't working is the dash lights and some of the Toyota capabilities like Crawl control, traction control, ABS .... This is why I was working on the 4WD ECU spoofing.

If you want to continue working on what @BLtheP or I have started please let me know and I can send you what I have figured out so far. Cheers

 

sure send it to me, the more information the better.
this i is the thread i used to come up with my plan.

https://www.tacomaworld.com/threads/4wd-actuator-troubleshooting-transfer-case-and-add.578262/

i have another excell sheet on my other computer with voltage values for each position as well, but seeing how you didn't even need resistors, i can toss the arduino idea out. i'm a software engineer so that was just more for my pleasure honestly. my assumption was that if the 4wd ecu was seeing the exact values, then the abs, crawl, tc would all function as OEM. though ive never really had great success with the crawl control, and i don't tend to use it, i'd like it to work.

i also have air lockers, so i dont worry about any of the locker hacks. i have the compressor on signal tied into the solenoid circuit. can cut those on/off while moving any time i want to.
the transfer case has twin sticks so i can do 2wd lo with that, plus the taco box for extra low. i'd really like to have a way to do fwd or rwd so i could do front tire only digs, but that may be excessive.

hoping to tackle it in a few months. i have a pretty large overhaul coming and was just going to knock it all out while the truck was down.

 

@Boost4brains -
> i'd really like to have a way to do fwd or rwd so i could do front tire only digs,
The FJ/4runner manual transfer case w/ a twin stick can't do front digs or front only because it is a chain driven unit. If you wanted to do this you would need another transfer case like the atlas, NP-205, etc... With the twin stick you get 4WD or 2WD-Lo.

You can see some of the stuff I did here and my observations after the modification with the manual and crawlbox. - https://www.tacomaworld.com/threads/official-crawlbox-bs-thread.422186/page-175#post-30446726