After swapping my 93 3.0 to a 98 3.4 I cant seem to get the transmission to shift out of second. I used the original 3.0 tranny which also has a transfer case (4x4) . I left the transmission hooked to the 93 ecu and ran the motor off the 98 3.4 2wd ecu. The motor runs great, I just cant get it to shift. I did this with the ecus because before I found this forum I just went by the seat of my pants... Thought I would use both until I weeded out all my issues, and eventually rely on 1 ecu. What will I have to do to correct this. I have the tranny out of the donor 98 2wd. Would it fit ahead of the transfer case out of the 93? I could then plug my 98 harness up to it. Thanks

 

I'm pretty sure a visual inspection of your 2wd tranny and the 93 tcase will tell you whether or not that is going to work or not. I'll go out on a limb though and say "No". Hey, I've been wrong before though.

 

It sounds like a purely mechanical issue, to me. I'd start with the shifter bushings (quick, and easy), and move on, from there.

 

im not sure but i think the trans needs to be ran off the 3.4 ecu cause it looks for input from the motor they work together

 

I think were talking autos but i could be wrong...

And I think you need a 3.4 auto 4X4 ecu...
Or you need to run a wire from the 3.0 ecu to the 3.4 ecu that tells when to shift...

 

https://www.yotatech.com/forums/f160...-a340h-128200/

Read up on this thread. Here are some basic "cliff notes" that i found.

On my 4runner I used the wiring for inside the tranny pan from the donor (to make it plug in). On first test drive the shift patterns were jacked up and I had a speed sensor code. Further inspection I found that the A340h uses a different signal then the Taco/4runner ECU's like to see. Because I had a 98 Tacoma harness the T100 ECU was a direct plug in with minor "pinout" changes. I modified the harness for the T100 ECU and test drove it, works great, transmission doesn't like a supercharger though.