2017 TRDOR transfer case not engaging

I have a 2017 with about 80k miles. The transfer case will not engage. The front differential engages. I have pulled the TC actuator and tested the motor with 12v and it works. I have checked the 4WD fuse and it is fine. It there a relay I am missing? Any suggestions of where to look would help.

Update: I have tried to engage both 4H and 4L from all different motions. From standstill to slow crawl froward or reverse. It is not a bound up issue. I have even played under the vehicle while a trusted individual engaged the 4wd. No noise or vibration comes from the actuator.

 

What exactly happens when you put it in 4wd

 

any codes?
What is the light doing?
what are you doing when attempting?

more info

 

I'm confused. You say the TC will not engage, but then you say the front dif engages. . . . . . . .what do you think engages the front dif?

 

Two separate actuators at the differential and transfer case, both have to work to engage the front end.

 

The 4wd light on the dash flashes when I twist the knob. I have tried engaging from a standstill, driving forward, in park and almost every other way possible. No check engine codes.

 

Learned something new, didn't know there was one at the front dif in addition to the TC. Why is that, is it just in the OR and Pro?

 

Pretty sure this is what you need to know. Not my video but lots of info.

https://youtu.be/GCY2BCdlU4I

 

Because if the front diff was always engaged then the Ring and pinion in the diff and the front driveshaft would always be spinning.

 

Sounds like it’s working but the driveline is bound up. Honestly something as simple as rolling resistance and tire variations can cause this. Check the tires to make sure there isn’t some anomalous wear that’s contributing to misalignment.

I replaced a tire that i blew that was slightly larger because it had significantly less wear than the others and that was enough to making shifting into 4wd a pain.

You may just need to drive back and forth slowly until it aligns.

 

Driving forward slowly while engaging 4 hi sometimes does the trick.

 

It's not, that's just the TC shift actuator he is dealing with. I just didn't know there was an actuator for the front dif also.

 

My post was for Op.

From original Op post the “motor in TC actuator works.” Doesn’t mean the gears are in the right spot. ~ 5 min mark in video. This video creators gears got in wrong position if you watch whole video.

 

I have removed, disassembled and reassemble the actuator. If you get the gearing in the wrong spot the truck throws an error. It was a 2 time trial that I got the second time. This mean the computer is seeing the position. It is just not getting power to move the actuator.

 

I’m sure if you went that far. You are 100% that no corrosion in any connectors. Could also could pull connectors at actuator and check continuity to plug up at 4wd ECU.

 

No corrosion. I will check continuity

 

How have you confirmed the ADD engages but the tcase doesn't? That is odd because the truck doesn't shift the ADD until it senses the tcase shift is complete. Do you get a solid or flashing 4wd indicator light?

 

That’s what I was thinking. Not sure how the ADD can properly be functioning if the tcase is not since one is supposed to happen before the light comes on.

Maybe I missed it in my reading/skimming, but is the light on the dash coming on? Usually the successful ADD actuation lights the light on the dash if I remember right.

 

The light on the dash blinks like it is going into 4wd

 

In this case the ADD won't be engaged because if the tcase is the problem then no attempt will have been made to engage the ADD and if the ADD is the problem then well.... it's the problem.

Again, how have you confirmed that the ADD is working?