2015 tacoma 4x4 problems

Another alternative might be to find a trusted private mechanic who is able/willing to read through the 4x4 diagnosis thread & do the diagnosing for you. Maybe he ends up charging you a few hundred dollars in labor to at least get an authoritative, specific understanding of exactly what is wrong, at which point you can then decide better what actions to take.

Given that there's a clicking noise coming from the drivetrain itself, it sounds like there could be actual mechanical issues in the front diff. Hopefully not in the transfer case...

 

Sure, I’ll admit the “grinding” noise is a bit of a concern.
But who knows, that’s a good way to help convince someone it needs a transfer case.
I mean, even if it’s not the transfer case that is causing the issue, “it was making a noise”.
So……..


Yeah, no thanks

 

If I was trying to go at this problem and understand where the clicking or grinding noise was coming from, I would put the truck up on 4 high-quality, solidly-planted jackstands and run the drivetrain (at idle throttle) in 4WD while listening carefully to the front diff, then the transfer case. I'd do that real, real carefully. I've heard that getting clothing, hair, or a limb caught up in a spinning driveshaft is extremely unpleasant.

 

OP was capable of removing the 4WD ECU and opening it up.
I think he is well capable of diagnosing this. You got it bud.

I mean, it’s pretty basic.
Write down your results. Compare them and see what’s “different”.

You can even post them up for us to look at if you aren’t sure what to look for.

 

The clicking noise is in the front end from like 15mph and under, goes away after that, like the front axles are not fully disengaged,, like I said new add,,,, they said the clicking noise was in transfer case,,, caused by me not putting it into 4x4 enough,,,,,, I would put back into 2wd, and the dash "ecu" would click a bunch struggling to disengage, I would unplugged battery, plug back in and it would be back in 2wd,,, I had to do this prob 5 times,,,, then one time it just clicked amd clicked and even unplugging battery didn't disengage, that's why Part of me thinks the relays are burnt, so the new ADD installed doesn't matter

 

Update, tested the 2 relays at work today and RY2 has a short/issue, added power and it shifted to NO,,,,but it's showing continuity at NC and slight cont at NC without power, guy at work who electronics guy said it's worn out