so im doing a 4x4 conversion, i know i need a longer outputshaft and i read a post on how to swap it out but i rather keep my original trans in tact and just buy a used 4x4 trans and transfer. my question is do i need the tcm from the 4x4 doner or can i use my original 2wd one? are the 2wd and 4x4 tcm the same? what are the differences? is the transfer case electronics separate from the ecu? if they are the same tcu i can just wire the transfer case to the switch on the console where the oem 4x4 selector would be. i have searched and found 1 post about the conversion but no info in my question. i commented with no replies back in a few weeks, im guessing because its an old post from like 2014 ish time. i can fab up the rest im just not good with electronics. lol any help would be greatly appreciated

I can't tell you specifically for an '11 Pathy, but almost all Nissan 4WD's that are RWD-based simply use different firmware in the TCM for the 4WD variant. The TCM is generally the same part but with different programming. The ECM firmware is usually different as well. Since the only way to change programs is to obtain the correct ROM-ID's for the application and then reprogram as if the ECM/TCM are new and blank, it may take a little research by a dealer to pre-identify the correct ID's for what you're doing.

VStar650CL wrote: ↑

Tue Sep 28, 2021 4:23 am

I can't tell you specifically for an '11 Pathy, but almost all Nissan 4WD's that are RWD-based simply use different firmware in the TCM for the 4WD variant. The TCM is generally the same part but with different programming. The ECM firmware is usually different as well. Since the only way to change programs is to obtain the correct ROM-ID's for the application and then reprogram as if the ECM/TCM are new and blank, it may take a little research by a dealer to pre-identify the correct ID's for what you're doing.

Ok so the tcu is different. Would you know if i can just swap it out of my auto 2wd pathy and put in an auto 4x4 one? The post i originally saw the guy keot the same trans and tcu, what he did was tear the trans open completely and swap out the outputshaft and put it all back together, honestly im kind of sketch on taking my trans guts out and have my garage look like the car version of texas chainsaw lol he then put an adapter on the tail and added the transfer then took him mike 4 years to finish the post and never really finished the electronic side with the 4wd selector...so thats why i still have questions.

You can certainly swap-in a 4WD ECM and TCM, but since the TCM is inside the Valve Body, finding out the right ID for the TCM and simply reprogramming it has to be easier. I didn't address the Transfer Case Controller, but that's a different can of worms and much more complicated. The harness wiring will be absent on a 2WD and you'll need to create it, so if you have no electrical talent, you're probably asking for big trouble trying to undertake a swap like this. I'd imagine you can kluje-wire the transfer case with mechanical switches and no safeties, but don't dare "miss" with the locks. The first time you do, you'll very likely blow something up.

so your saying that in order to swap in a 4x4 trans in a plug and play scenario i have to also swap the ecm? wtf.....in that case i rather go the texas chainsaw route and pull apart my trans. post i saw guy didnt change any electrical not even trans tcm, pr programed anything, he simply put in the longer output shaft and housung adapter......i might as well just ls swap it and do a 4x4 system out of an old k10 where everything was manual with no electronics and a big ole knob for the transfer case

Did he put an old mechanical unit in there? The 4WD on an '11 is strictly electronic (both versions), so if you're saying somebody did it with horseshoes and levers, I have no idea how.

no he used an r51 unit and transfer, what im saying is if it takes swapping out the ecm and the tcu and the trans then i might as well use an old school unit. would i also have to swap ecm?

No, with a manual unit I very much doubt the ECM will notice.

isnt the tcm in the trans? or is it external?

It's inside the tranny, attached to the Valve Body.

so all i need is the trans, transfer and front diff, thanks bro!!!