Did I damage something internally when replacing my ABS sensor?

I assume the ADD was plugged in when you took these readings?
If so, the whole ADD actuator is short. It’s down for the count.
It never once hits 12v as expect.

And the transfer case
Well TL1 and TL2 have found a permanent ground.
And TL3 can’t find a ground……..

We should also note that you truck has likely never once made it into 4WD. Ever.
As the 4WD detection switch has never been pulled to ground.

Uhhhh…. I’m going to have to consult with @Dm93 on this one.



And then there’s this?
It seems the ADD wiring is grounded somewhere?

 

Yeah everything was plugged in when I did all these tests. I've owned this truck for almost a decade, I can assure you that 4WD and 4LO have worked. I live way deep in the rocky mountains of Colorado and wheel this truck frequently.

 

I mean it never went into 4WD at the transfer case during the testing.

 

Right. When I flip the switch into 4WD I don't even get a sound or a click or hear anything try to do anything.

 

Your result are showing the switch itself is working correctly.
So that’s not the issue.

TL2 is showing you in 4WD at all times. Even when you are in 2WD.
And your ADD wire is being pulled to ground at all times (shorted to ground)

According the Dm93’s shift sequence chart, the ADD won’t even attempt to engage or disengage until the transfer case limit switches are correct. I’m kind of waiting on Dm93 to see what route to take here.

 

If my hypothesis of you having the pin numbers reversed when you checked voltages at the actuator plugs is correct I believe we already proved the wiring isn't shorted to ground but it wouldn't hurt to double check.

Yea it appears there's a problem in both actuators, you said you replaced them but were they OE or aftermarket? Do you still have your old ones?

It's basically in lockout mode because the limit switches aren't in a plausible range so it's not gona do anything until we remedy that.

 

He says, with the ADD unplugged, the ADD wire is still at 0v. And that’s checking at the 4WD ecu?

 

I don't have the old ones anymore. I replaced the ADD actuator and went cheap. It worked for about a month, then failed. I replaced it with a more expensive one. It's this one right here: https://www.carparts.com/4WD-Actuat...k=2023-10-19T20:29:06Z&bsft_lx=25&bsft_tv=351

I also replaced the transfer case actuator with this:

$119 36410-34015 Transfer Case Shift Actuator Replacement for Toyota 14-19 4Runner, 05-15 Tacoma, 00-06 Tundra 4WD 3641034015 NICEKE

https://www.amazon.com/dp/B08K8KS376

When I replaced the transfer case actuator, I left the old rod in and installed the actuator around it. I'm pretty sure I did everything right, but maybe the contacts are in the wrong position?

 

Pretty improbable for it to be 0v at the 4wd ECU end and 12v at the actuator end (the wire would have to be broken and shorted to ground on one end and making contact with another 12v source on the other end for that to happen) so something was missed there.

If you tested the right pins it sure looks like something is going on in the ADD Actuator as all the limit switch circuits are pulled to ground with it plugged in.

Very possible to mis-time it, I have to go back and look at your voltages again to see if it's in a plausible position.
Meanwhile double check your voltages with the actuators unplugged (all the limit switch circuits should be at battery voltage), if that checks out I think we need to first see what's going on in the ADD Actuator.

 

At this point, I’d unplug both actuators and see what my voltages are.
I’m getting confused with all the test.
Some were tested reversed, some were right.

That’s just me. But that’s all I got….

 

I'm heading outside right now to unplug the actuators and retest everything. Be back shortly.

 

I unplugged both actuators and took measurements:

 

Double check Pin 3 (Light Green/Black) at the ADD actuator and see what it is there.

 

I disconnected and double checked and it's still 2.3mV

 

Ok so we have nothing on that wire at the ADD Actuator end or the 4wd ECU end?

 

That’s from the ECU. Did I do a stupid?

 

No I just asked to verify you have the same reading at the ADD connector Pin 3 (Light Green/Black)

 

ok give me a sec and I’ll go look at that. Looking at the connector, is it left to right 654321 or 123456?

 

Srry for all the retesting, I'm just trying to make sure of our readings on that wire to be sure it really is pulled to ground so we aren't chasing our tail.

 

Facing the connector on the vehicle side it should be 123456 but verify your wire color (Light Green/Black).