4wd System Operation & Help Thread

I saw that, I'm concerned about the 1.7v on the ECU ground and the fact that the problems started after a clutch job. Trying to figure out how it could be related other than a pinched wire or damaged or improperly connected ground somewhere.

 

That’s what I’m thinking too?
I suppose there is a small possibility there is a problem at junction connectors J13 or J14.
But it’s not likely. And I can’t seem to find the diagram where they are. I suppose it’s worth testing at those connections. But I doubt that where the issue is.

 

I will check that kick panel ground I think something might be ran under it and compromised the 4x4.

just checked it, it read .4 so I’m not worried about that ground. I didn’t have anything ran there like I thought I did

 

Looks like they are behind the right kick panel as well.

 

It's a long shot but is the clutch pedal switch at the bottom of travel adjusted/working?

 

Clutch hasn’t given me any issues, what would be a tell tale that it hasn’t been working

 

That would only affect being able to go in and out of 4 low.

 

.4v measured on the ground wire at the ground?
How are you checking it? If you are checking the wire with it still connected, I believe you are essentially doing a voltage drop test. Which means, there is voltage there? @Dm93

 

My leads measure around the same and I have a nice fluke multimeter so I trust it, but that was key off and nothing changed when key was on

 

Yes depending on where the meter ground is connected, ideally you want no more than 100mv on a ground.
I think a voltage test from battery negative to frame, body, and engine would be a good idea in case there's a main ground that's bad, although I would think if that was the case other systems would be affected.

 

Be nice if you could isolate the White/Black wire from IE ground.
Then test it to battery negative.

 

i just realized, it was .4ohms not volts at that ground, i did check and pulled no voltage there

 

What a great thread!!!!

And I'll add this to it..

Might as well add some solder to the two joints at the motor if when the cover is off, this often solves or prevents the corrosion problem that causes the common no 4WD engagement when commanded and the dreaded blinking light.




And on a side note thta's related to 4WD System, I polished the ADD shift fork with fine sandpaper and some WD-40 to help a smoother engagement when I recently had everything a part.. which can be found here https://www.tacomaworld.com/threads/monkeyproofs-misadventures.697489/#post-24678936

 

Good tip, I added a link to your post.

 

Sense I deploy soon, I think if I can’t get it done by the time I push out I’m just gonna have to do the fj swap when I get back along with the add delete in the front. No more electronics to make me angry

 

What did you test? The wire or the bolt at IE?

That is odd.
You have a voltage of 1.7v on the Ground wire AT the 4WD ECU.
I’d take another reading at the J14 connector pin 4. (Note that all the wires on J14 are joined when both connectors are plugged in)
DM93 posted the J14 location a few post up.

 

I tested off the bolt but I’ll go ahead and check that after work tomorrow, I feel like we are getting close by we I mean all of you figuring it out for me

 

Hopefully, I hate gremlins like this they are very hard to troubleshoot remotely.

 

It’s embarrassing that I went to college for electrical work, and work as a heavy equipment mechanic in the navy and still feel so clueless when presented this challenge