i have read all the threads and been looking at wiring diagrams for weeks but i still have a couple of questions. i am using a 99 auto ECU to swap into my 90 MT 4runner. i know i need to jump the neutral safety switch to fool it and let it start. i know i need to run a new wire for the starter and one for the fuel pump relay.

from what i have read it seems i will be cutting the ends off my original 3.0 body harnesses shown below. i will be leaving enough wire to splice the 3.4 wiring onto



and then removing and discarding the ends from the 3.4 body harness shown below




then splicing the wires from the 3.4 body harness to the short ends i cut off my old 3.0 harness so they will plug into the rest of the vehicle wiring. i am not interested in the 4wd light and reverse lights working so i think the only wires i need to swap for the two body connecters are the following

Oil pressure gauge to oil sender (1 wire)
Coolant temp gauge to coolant sender (1 wire)
Check engine light to ECM (1 wire)
Speed sensor from combometer to ECM (1 wire)
Tachometer from gauge to Igniter (1 wire)



HERE IS THE PART WHERE I GET LOST
my 3.4 ECU has FOUR ports. i know the engine harness plugs into the first three ports. i am fairly certain i do not have to cut or splice any of these wires. just plug them in and go.



this last port i do not have a connecter to plug into it. i have checked all my wires and do not see any ends that would fit. is this port needed for the swap or should it be left empty?


what about the wiring to make my rear window roll down? i didnt see it in any diagram of the body harnesses but it doesnt work unless i have the old 3.0 harness plugged in

 

That's how my ecu and wiring was too. What your going to need to do is go through the EWD's for the doner vehicle and figure out which functions that plug contains. Then source out that plug from the stealer-ship or junkyard (I found one that fits off of a Camary), splice the wiring, and you will be good to go.

 

Ok I found the plug for that last port in the section of dash wiring I have from the donor. Now I just to need to get the wiring diagrams from Toyota and see what wires need to be spliced over

 

yessir, or from https://techinfo.toyota.com/techInfo...9-1&SMLOCALE=U. Have fun!

 

heres the free manuals http://www.ncttora.com/fsm/index.html

in my opinion the tis site sucks and is un organized

 

i think the empty port on the 3.4 ecu is for the limited model 4runner. the antitheft stuff,my donor was an sr5 not a limited with the chip in the key. just gettin into the wiring on mine.

 

mine was a limited so it did have the chip key. hopefully that wont be an issue

 

i think it will be an issue. maybe you will need the 3.4 ignition with the key or find a way around this to fool the ecm to think the chip is in your key. like an o2 simulator.

 

i dont have the key or the ignition cylinder. i think the chip key is just a starter kill. if so it wont be an issue b/c we run a new starter wire anyway.

i did find the plug for that last port so hopefully some creative wiring will solve any issues

 

nevermind i see you found what you were seeking

 

your post was actually very helpful. i'm gonna repost what you sent originally in case it would help others

 

ok, so anyone know if the immobilizer is going to give me an issue? looks like it is a fuel cut and spark cut. i can rewire the fuel pump but dont know about the spark cut?

i'm pretty certain the 4runner was a limited b/c a cut key wouldnt start it. i dont have the body so is there a VIN on the frame somewhere?

anyone used a ECU from a limited for the swap? if not how do i identify a non immobilizer ECM?

 

According to my EWD I don't see any reason you'll have problems with an immobilizer. Can you post up whatever you are looking to so we can see why you think you might have a problem? I've never heard of a "limited" ECU causing any problems with such. In a previous car of mine (Cadillac) the chip in the key was just a resistor and the whole immobilizer part was contained in the ignition cylinder. You are using the 3.0 ignition cylinder and key so I don't think you'll have problems. Post up what you have.

 

Why not just change the ECM to a known non-immobilizer version? Unless I am not thinking of something off the top of my head, I see no reason why a simple 97-99 auto ECM wouldn't work.

That seems MUCH easier than messing with all that. You can get one for fairly cheap, =\- $50 or so I would think. Hell I may even have the auto one that I used for a while around i'd sell. Let me know if you are interested and I'll look.

I cant remember the cutoff but at worst you MAY have to change to MAF. If so you could recoup the cost by selling yours. There is always a market for good, used Maf's here or at ttora.

Peace of mind would be worth it to me personally.

 

That is the diagram I am looking at. Looks like the immobilizer is tied into a plug on the computer. Maybe the "c plug?" According to the picture. From what i have found it will disable the fuel pump and spark. I can wire the pump differently but no way around the spark cut.

If I can use a 97-99 computer I would go ahead and buy another. I thought I had read somewhere that there was something different with just the 99 model.

 

fixed link

 

https://www.yotatech.com/forums/showthread.php?t=247639

The third pic in that for sale thread says it is from a 99 limited 4runner. It has an extra plug that mine doesn't, the red one in the middle. Maybe mine isn't a limited model after all. Wish there was a way to know for sure


just checked the part number on my currect ECM and it pulls up as a 98 4runner not 99 like i was told

89661-3d372