Alright, Before anyone says anything. I did check the 4wd no worky thread.. but none of it describes what my problem could be.

Let me start from the beginning, Last year in the winter, 4wd engaged and disengaged perfectly. until one time, went to engage it, and it did nothing, No TCCM click under the dash, motor on the t-case did nothing, light on the 4hi button did not light up.
driving down the road sliding around in 2wd.... 30 minutes into the drive almost home, I thougth I would try it. push the 4hi button, and bam, 4wd is acting like nothing was wrong before.. like it took a 30 minute break


Now, lets fast forward to over the summer. I do not use 4wd in the summer. I do not off road, i live in the city.
Noticed one time while driving down the road that the 4hi light was on the dash... i pulled on a side street, was able to spin the front drive shaft so i knew that the t-case was not engaged, so I pushed the 4hi button, and the light turned off.


Now lets fast forward to last night.... Go to target, 4wd working perfect, shut the truck off while it was in 4wd..
Turn the truck on, the 4hi light is not on, i know it was left on, but was trying to convince myself that maybe it was turned off.
Start to drive, and instantly knew that it was indeed in 4wd. (icy snowy roads)

Try to push the 4hi button, and nothing, does not blink, no tccm click.

Get home, put the truck in neutral, push the 4hi button, both 4hi and 4lo on the button flash like 3 times, then the 4hi light comes on, i hear the tccm click, push it again, light comes off, tccm clicks.

I think its out of 4wd, nope. try to push the button while driving, it does nothing. no light

Pull in the driveway again, put it in neutral again, push 4hi, both lights blink again, but this time when the tccm clicks, both 4hi and 4lo stay solid lit.

push the 4hi button again, tccm clicks, and the lights go out.

By this time, I am annoyed and turn the truck off and go inside. 30 minutes pass, I go outside cause i had to move the truck for someone, get in the truck, put it in neutral, push the 4hi button, light comes on, tccm clicks, light turns off and i hear the t-case motor.
i reach under the truck. Front shaft spins freely. put it in drive, give it some gas, sure enough, its out of 4wd.


Now TODAY. Chelsea is taking the truck to school, a lot of hills around there that are snow covered. she trys to put it into 4hi, pushes the button, and nothing, no light on the 4wd switch, no tccm click, no t-case motor noise.



Hope Didnt lose anyone LOL

 

Weak man, I hate when the whip acts up when the wife is trying to go somewhere. Especially when she needs\wants 4x4.

flaky switch or tccm?
I don't know the answer to your problem, but I might try a pick and pull for a switch and tccm and see if changing either of those cures it.... possibly check grounds.

Good Luck man

 

Geez Rich, another "...but my problem is different" thread?!? You're lucky your name is in green! :P

Sounds like a connection ussue. Possibly moisture inside the shift motor causing the contacts to not contact occasionally? I'd guess it's not the TCCM, because it does work occasionally. Ground issue?

 

HAHAHAHAHA!!!!!!!!!!!!!!!!

Yeah I would start by checking all related connections and grounds from continuity and moisture and go from there as Diata stated.

 

LMFAO Diata...

That is what I was thinking. I was trying to get ideas before I start checking connections... as its 3 degrees out and will not get above that for a week LOL

Last year when it did this, I got some switches at the pull it yard and tried it, and it still did the same thing.
I am going to see if there are any stored codes tomorrow with the 4wd and go from there. But I am at the connection issue. and if its not that, then will have Chris pick me up a tccm from the yard.

its not a vac issue, engages and disengages fine, when it wants to work LOL

 

so, I checked the codes, it threw code 2, which from the 4wd no worky thread.. that is encoder fault.
Usually ends up being a dirty/loose connection at the encoder motor. So next weekend when I have access to a garage, I am going to crawl under there, pull the connection off, clean it all up, and put it back together.

 

Hope that solves your issue for you

 

We can only hope so. Last winter when this was happening, I was like 'i should clean the connection at the encoder motor" all summer long, didnt do it..... winter again, acting screwy again...... LOL win.

 

I hate it when that happens!! I do it to frequently myself

 

But I will have access to a heated garage next weekend, so working under the truck in that wont be a huge problem.

Now, where is the encoder motor located LMAO