4WD ECU Spoofer for FJ Transfer Case Install

Interesting, when I did similar on my 2017, (per my faulty memory and not looking at notes), I had CAN bus errors but dont remember ABS/VSC fault.

That said, I may have also had ABS VSC failures, but don't remember, it has been a few years and I am getting way too many years on the pitiful brain...

I suppose any tacoma with electro/hydraulic brake booster (which also has the ABS ECU) will also have a 4wd ECU... so the truck always knows it should be there for us... It might be interesting to see how a truck behaves that is not an OR/Pro, it might be different...

 

Possibly because he has the collision stuff where the truck stops itself? Which I assume relies on the skid ecu. I don’t know if ‘17s had that.

 

I forgot what I was supposed to be working on, was it (32) panel grid tie solar PV?


A note from an idiot, dont try to do that in the summer in Florida... and dont buy parts from a company that ships XPO...

 

Yeah 17 doesnt... absolutely could be the difference. (if there is a difference)

 

Always good to hear from you, man

 

Yeah 2016 and 2017s don't have all the new fancy nannies. They revamped the 3rd gens in 2018 with the 360 camera, assisted braking etc etc. That's why if I ever went with another Tacoma, it would be 2017 or less. My 2016 is just a base truck with a nice navigation screen, no extra nannies

 

Tell him to open the ADD and solder the contacts to the motor, then RTV that bitch shut

 

Okay, I found the wiring diagrams from Toyota. The transfer case can be spoofed fairly easily from what I can see. The dilemma, I cant find a male connector for the transfer case female plug. The 12 pin connector is used by Toyota in several applications, but it’s typically plugged into some sort of module such as our transfer case actuator or igniters.

here is a link of the connector, I’m looking for the male version to plug it into. The part number and specs are in the listing so I’m not going to copy and paste it.
https://m.th.aliexpress.com/item/32965438473.html?trace=wwwdetail2mobilesitedetail

technically, you can cut wires and jerry rig something up, but that’s against my morals. I personally never butcher or splice into factory wires. Anyways, I’ve been looking for the male end for days now, with no luck. I don’t know if someone has better resources than I do.

 

Someone gave me an idea to put a 10k resistor at the female connector instead of at the ECU. Just a thought but with my basic knowledge of electronics, I would struggle with trying to reverse something if it didn't work. I appreciate all the research though, it may just be something that can be done. I'm prepared to live without ABS or trac control unfortunately

 

Pretty much. Relays and resistors will trick the Ecu into thinking the transfer case is there and that it’s shifting like it should when commanded. Personally I’d like to keep the front axle actuator working and letting the EcU open and close it. The ECU thinking the transfer case is present and doing what it should be will keep it happy and the front actuator working. My reasoning behind this is to throw in a lunch box locker in the front axle.

worst comes to worst I can buy a used or aftermarket actuator and plug it in.

 

I had hoped to do this as well but the CANbus stopped me from doing it. So if you figure it out, let me know!

 

Do you know if this would work with the ADD unplugged too? I'm assuming the ecu is looking for a resistance from the ADD as well...

 

Correct, ECU is looking for a resistance from both actuators.. so I bought 2 10k resistors, just waiting for someone else to try it and do a write up

 

It worked! Just gave it a try, add and tcase actuator are unplugged and the truck isn't throwing any codes!

 

That is how the original schematic was drawn in the original post.
Resistor at the ECU across the ADD motor and Transfer case motor.

See purple circle

 

So you put the resistors at the ADD/t case actuators wiring harnesses INSTEAD of splicing into the 4WD ECU? And it did work?
If so, which pins did you use for each (because they're different connectors)? Do you have pics? Did you do any soldering?
What's your new process for getting back into 4wd (shutting off abs/trac control)? Does the oem knob work to turn them off (essentially throw codes to shut them off that way)?

 

I actually purchased @lapoltba 's 2lo mod plug and play harness and rewired it to this wiring diagram. I didn't take any pictures and I did have to de-solder and re-solder a bunch of terminals on the relay but it really wasn't a big deal.

My mod works exactly how BigWhiteTRD had intended originally. Shut the truck off, turn the dial to 4lo, hit the switch, and turn the truck back on. Worked like a charm!

 

If you dont mind, I will add you as a success to the original post, so people can tag you to ask questions.
I always felt it was a rather non-elegant solution. (although i built a first test harness, i never actually tested it on my truck). How bad is it to use?

 

Absolutely!
It's actually very easy to use. I usually don't need the truck's 4lo capabilities for most things (since I have the FJ t-case, I just throw it in 4lo, and it's good enough 80% of the time). When I know I will be needing it, I usually need to air down my tires, so I'll just shut the truck off and switch the truck over to 4lo at the same time.

 

@Sep1911 @BigWhiteTRD @bravinci I've finally done it, I've found a completely internal solution to spoof the 4wd ECU into thinking you're in 2wd. (I have a TRD Sport so I have no need to get the computer to read Lo to turn on the Locker.)

Did the t case swap July 2021. Twin sticks, stiffer detent springs (thank you Brav), and the ADD Switch to manually control the front actuator. Suffered standard codes for 3rd gens: ABS light, traction control light, and 4wd change error.

The ABS and traction control were just one time codes thrown when the truck was started that I could exit out but the 4wd change error would come back every 5 seconds. I wouldn't be able to read the digital speedometer, miles left until empty, Fuel mileage etc. Not a deal breaker, it's the same as an older truck lol

Up until now, I hope I described similar symptoms yall have experienced. This is where I began to play with the computer.

August 2022 I finally realized I could just pull the 4wd fuse on the internal fuse box. I don't need the ecu/switch to get power so what can it hurt. By doing this, it completely shut off the 4wd change error. I could, once again, see my digital speedometer, Fuel mileage etc without getting that constant error. Awesome!

Skip ahead to December 2022. My buddy picked up a Snap-On Solus Pro because he does a ton of side mechanic work. I asked if he could clear my ABS and traction control codes so I'll no longer have dash lights or the messages when I start the truck. He attempted to BUT wasn't able to clear the ABS message when I started the truck and turned on 2 more lights relating to the traction control. So the traction control message after a start went away but my dash now looked like this:

With these 2 extra traction control dash lights, my cruise control no longer wanted to be set. This is a similar situation when you take off the sway bar, set cruise control, and take a turn: these traction control lights are somehow associated with being able to set cruise control. Now that they were showing permanently, I couldn't use cruise control. Big problem since my commute is 30 miles one way.

My only thought was to try what I did before: I took out the 2 ABS fuses in the external fuse box. That just brought up a completely separate error so dead end.

Skip finally to today: we gave it another go to see our other options. Same codes being thrown for all the ABS and traction control. I brought the truck to him still running, he plugged in his computer, and it came up with all ABS-related codes. Makes sense, ABS runs traction control. He wasnt able to clear any codes here.
We turned the truck to Acc instead of running but kept his computer plugged in. On his computer he went to "Signal" and when he entered this, all the traction control dash lights began to flash. In the signal category, he was able to disable reading a signal to the 4wd ecu. Doing this shut off every single blinking traction control light. Seems promising..
I hopped back in with the computer still plugged in and not a single error code or message was displayed. I couldn't believe it. He disconnected the computer and I went on a test drive. I found a patch of ice and hammered the brakes. ABS and traction control lights began to flash like they would in a stock orientation then shut off. Seemed like my ABS was working like a stock truck. I went down the road and was able to successfully set cruise control. Another win.. I got back in a parking lot and pressed the over traction control disable switch. IT WORKED TOO. I was able to press it to get my LSD and I was able to hold it to completely disable it; ALL LIKE A STOCK TRUCK.

Ultimately, I think by first removing the 4wd ecu fuse to shut off power one way then disabling the signal from the ABS ecu to shut off power from the other way reverted the truck back to its stock 2wd functions. I now have all traction control functions, a functional shut-off button, functioning ABS, and most importantly cruise control. I think by accident, I've figured out a way to trick the computers to provide an internal solution for the FJ Cruiser Transfer Case Swap 4WD ECU Spoofer.

Comments?? This is HUGE imo