a few months back I got a message saying 4x4 fault or something, the light went away and I forgot about it. the other day I was in some mud and noticed my truck quit moving. I turned on 4x4 and nothing happened and I could tell my truck was engaging 4x4. I got out and locked the hubs manually and the truck engauged 4x4 without issue. what is the first thing I should look at??

 

There's probably a ton of esof troubleshooting guides in the older SD threads like 6.0 or 7.3 as well as the general SD forum. Our trucks are too new for that info to be easy to find here.

I'm not being a tool by telling you "try the search button", just making a suggestion. The system probably works different for diesel vs. gas because of the vacuum system so I would stick to diesel sites.

 

The auto hubs usually won't lock unless the truck is moving. Once your stuck it's usually too late.

If something is broken, first check for leaks in the vacuum system. Easiest way is to check the vacuum pump, see if it turns off or running constantly. If it's running constantly you have a leak somewhere in the main system, check for broken vacuum lines or connections that came loose. If it does turn off the main vacuum system is fine.

On the previous models the blend door in the HVAC was operated by the main vacuum system and if there wasn't sufficient vacuum the HVAC system would always be on defrost. Not sure if this is true for the 2011+.

If the pump turns off go ahead and engage the 4x4 switch and see if the pump turns on. If the pump does turn on and then shut off again, you do not have a leak. If the pump turns on and never turns back off you have a leak in the ESOF vacuum system.

If no leaks are present most likely you have a bad locking hub that has dirt/debris stuck in it or broken in some other way.


That will at least get you started. Let us know what you find out.

 

I learned that the hard way the first time.
*Turn 4x4H ****
"Please pull forward..."

Me: Well crap...

 

Do a visual insp on the vaccum lines coming off the back of the steering knuckels and follow them up a ways....see if one got snagged by some brush. Had a F-150 last weekend with no engagment of the front end and just did that-found his old battery had leaked, destroying the lines for the actuator!

 

Hope this video helps...it's from a fellow FTE member. IMHO...he does an excellent job explaining and showing how to detect leaks.


<iframe width="640" height="360" src="http://www.youtube.com/embed/MoI-BbisYEs" frameborder="0" allowfullscreen></iframe>


Good luck...and please post back when you get it fixed.


biz

 

I had the "Check 4x4" pop up last year, CVH solenoid crapped the bed. Here's the result of it:

https://www.ford-trucks.com/forums/1...l#post11096342

I haven't had any engagement issues since it was replaced.

 

What about 4 wheel low? Doesn't that require you to stop and put it in neutral?

 

yep and to pull forward slowly to fully engage. You pavement princesses...when in doubt, throw it in 4x4 auto. If you don't plan to get stuck, you will. Guaranteed...every time.

 

Darn....OK. I have used lo and high on this truck and the previous one, just never after getting stuck.

It's plan B - and Savage you are exactly right what that is.

 

I think the auto hubs suck. My new F-250 wasn't engaging and never worked when it was too cold out in the winter. When it got to minus 20 to 35 below this winter I just left the hubs in manual. Not much auto about auto hubs when they don't work. They worked fine when it was warmer though. And not all systems of 4x4 require the tires or truck to be rolling before engaging but ya better know how your truck reacts cause no fun to be stuck in 2 wheel drive when showing 4x4.