Not your average 4wd problem

I am thinking about a used transfer case control module. It is strange that I get 4hi after the battery is disconnected overnight and then none after i shut the truck off and on.

 

Ever come to a conclusion on this issue? I am having similar problem where transfer case actuator will pull the rod out for 4hi, but not further out for 4lo and is not able to push the rod back in for 2wd. I take the spline gear out of the actuator and it can perform all functions when not under load. All kinds of different combinations of 4hi/4lo flashing lights, doesn't seem to be any rhyme of reason to them.

 

Did you check for corrosion on actuator contacts?

 

How long have you owned the truck for, and how long has it been doing this?

 

Both actuators are brand new, ADD actuator is a Dorman. T case actuator is OEM. Bought the truck to sell, I knew the Tcase actuator was bad when I bought it.

 

Stating the obvious, but when you're shifting into 4 LOW, your transmission is in neutral? The only reason i brought this up was that i didn't realize that when i bought my 4wd tundra....neither did my brother in law for the whole 5 years he owned it before me.

 

You're not the first person to get bit in the ass with that one...

I feel like that info is on the overhead visor or something though, on a little card slid into a plastic sleeve. I know for a fact it's right there, in your face, if you actually read the owner's manual. (I have no excuse)

I didn't go there b/c he said "can't push the rod back in".

 

Right, I was in neutral when trying to shift to 4lo. I heard somewhere that you have to get the tcase actuator "in time" but have yet to find any real information on that. What do you guys know about that?

 

@Tundra2 if not too busy, didn't you have to deal with this during your misadventure?

 

I did the cleaning of both actuators about a year ago because I could not engage 4Lo. I pulled the gear on the TC actuator as well to remove it. I also had issues with the proper "clocking" and upon reassembly couldn't engage Either 4Hi or 4Lo. After many hours of wash/rinse/repeat I got 4Hi working, but not 4Lo. My A.D.D. also was able to perform all commands disconnected from the TC. One thing I was not able to get an answer to was the 3 positions of the TC shift shaft, until now (red highlight). My idea was to see if I could Manually engage the TC into 4Lo to make sure there wasn't a mechanical reason for failure to engage. My understanding is when both actuators are in 2Hi the only thing that turns with the front wheels are the CV axles, so the front diff and front drive shaft are at rest. There are also 2 switches on the TC (Edit: TC actuator) that tell the Truck the position of the shaft 2HI/4Hi/4Lo IIRC.
As it sits now I have 4Hi, and would rarely if ever need 4Lo, but this bit of info about the shaft positions was something I was looking for. THX bodeslim

 

So it seems that i was able to 'time' the tcase actuator. Tcase shifts in and out as it should. This was a helpful read...https://www.yotatech.com/how-tos/a/toyota-tundra-how-to-replace-transfer-case-motor-actuator-414483

That being said, still don't have 4wd. Any of you guys know how to go about testing the ADD actuator of 4wd computer?

 

Others on here - when nothing else made logical sense - have found the 4WD ECU to be faulty. It's happened enough that I feel it worth mentioning. The 4WD ECU itself is behind the passenger side kick panel.

This is often the video that gets shared around here which shows some stuff that's above my pay grade with regard to signaling/testing functions. Not sure it's dead-on what you're looking for but maybe it helps give ideas?

https://www.youtube.com/watch?v=TmuEVv1neVQ​