hey everyone. new guy here. got a 2010 f150 xlt 4x4. love this truck. never had a single issue with it up until now. currrent reading on the odo is 107k. i have been trying like heck over the past few weeks to find a fix for my 4 wheel drive issues. everything mechanically seems to check out just fine. but getting there is the problem. Its as if the 4wd works after i cycle the shift **** back and forth a few times. i get a check 4x4 followed by a wrench light on the dash. eventually it will work and stay in 4 wheel drive. until today i switched back to 2wd and it was still in 4wd. i didnt even get a check 4x4 or wrench light. drive down the road a little bit and tried to go back into 2wd again and it finally did. worried the problem lies in the pcm. i know this is very little information to go off of. hoping someone else has/had this same problem that can help out. thanks

 

If all vacuum hubs/ lines solenoid stuff is in order as you mentioned - the other common problem is the shift motor itself gets lost when the glue holding the disc to the hub inside unit lets go over time telling pcm to give wrench error . I jb welded the disc back to hub in my plow truck and been fine since. Just change out motor if you don’t want to repair it. That little silver thing in lower center photo is the hub that is glued to the center of the white washer looking thing next to it ( acts like a rotary switch) Good luck

 

I thought TC motor also but hubs were still locked in too while in 2wd mode. Thanks for the reply btw

 

only advising possible fix if ur vacuum hubs are working fine. Tons of info here on forum for fixing the hubs vacuum issues-

 

Shift motor is a common failure, includes the position sensor, most likely that is the issue.

How do you know your hubs aren't disengaging? the truck has no awareness of this, you will have to check that yourself, jack up a front wheel and with the truck running in 2H, spin a front wheel, make sure it doesn't turn the axle (do this for both wheels)

 

Does the TCM "tell" the vacuum solenoid to lock/unlock front hubs??? The truck didnt want to move while turning at slow speeds. Ill check for sure this weekend. Thanks for all input guys

 

Yes, it does tell the hubs to lock/unlock, but only so far as the solenoid signal.

If you're having binding like that, it's back to the shift motor not changing the drive mode, you'll have to check anything else *after* you fix the shift motor issue as they're all downstream.

 

Man thank you so much. I just figured the PCM powered the vacuum solenoid and TCM separately. Guess i got some parts to order. Might as well do a fluid change too!