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so a couple of questions. i have two projects going on. i have two 1990 4runners that i am puting 3.4l motors in. one of them is almost done i used the motor out of a 99 tacoma and a harness built by toy only swaps. and the other motor and ecu is out of a 99 4runner. where my question lies is why does the ecu out of the tacoma only have 4 plugs on it and the ecu from the 4runner have five plugs. also how is this going to affect the wireing im sure someone out there in toyota-land has used the harness and ecu out of a 4runner. im looking for some advice should i just use what i have or find a new harness and ecu and go with what i already have done and just copy it also i have included pics of the two ecu's and pics of the plugs i got with the motor out of the 99 4runner. i did not get to pull the engine harness ecu out of the 4runner i just got this all as a package deal. if i use this setup do i need any other plugs any input would be helpful thanks.
the 3 plugs that come off the engine harness from the 99 4runner this is the other side of the plug that has the flip lock on it from the 99 4runner 99 4runner ecu 99 4runner ecu with 5 plugs 99 tacoma ecu 99 tacoma ecu with 4 plugs
I am right in the middle of doing my 3.4 swap with a 99 4Runner MT engine. Mine also has the 5 plugs yours does. The thing I noticed though is that the middle plug did not actually seem to have anything plugged into it. I believe that this plug was probably used for extra features that my donor did not have. I would guess that the Tacomas by default didn't have all the same amenities that the 4Runners could come with and therefore never had a configuration with 5 plugs required.
As to what these extra features are.. I am not sure and only can guess at but I am thinking possibly things that were in the limited 4Runner, like the immobilizer or possibly auto trans stuff, or maybe the more complex hvac system? Just guesses, but my 4runner engine has the same plugs as yours coming from the engine harnes, I believe the missing plug in the middle would have came from body harness additions.
If you are looking to sell the 4runner ECU let me know, I would be interested in it. I have a 4runner harness for my swap but need that ECU.
Thanks, and good luck!
10-29-2016, 01:01 PM
