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Junior Member
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6 Posts
Discussion Starter #1
I had to get my PCM reset couple of weeks ago and this morning I wanted to use the 4 wheel drive for the 1st time since the reset and it didn't engage in 4H or 4L. Would loading the PCM incorrectly effect the 4 wheel drive system operating correctly or is it possibly another issue?
 

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Junior Member
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6 Posts
Discussion Starter #2
hmm

I just went out to look over the system, I rotated the hubs and now it works. Could it be possible water maybe in the system and since last night got in the SINGLE Digits it cause the problem? If there might be water in the system how would I go about removing the water?
 

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Senior Member
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1,324 Posts
so 4WD works when you turn them to lock correct? When they are in in Auto they are vacuum actuated so either a vacuum leak or the vacuum pump isn't working. I wouldn't think it is tied to the PCM but I don't know much about the 08 to 10 trucks. The ESOF electronic shift on the fly works pretty much the same on ford trucks. If they turned thats a good sign they are not frozen up.

the biggest problem seems to be not cycling them often (say 1-2 times a month) and turning them manually into lock. The ones on my 04 were frozen so I opted to replace them with WARNS solely due to price.

Hopefully someone with more experience responds.

:toytruck
 

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Junior Member
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31 Posts
I had the same problem with my 08.$%^& truck got stuck on frozen dirt! I took it to Ford and they told me one of the vacuum lines came off! I asked how that could happen and they gave me some story about how I could have run over something on the road ...BS...I had recently had the truck in for maintenance including tire rotation And they charged me $108 labor! short answer: look under the truck and make sure the vacuum lines are attached ... BEFORE you take it to the dealer!

:ranton
 

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Junior Member
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6 Posts
Discussion Starter #5
I had the same problem with my 08.$%^& truck got stuck on frozen dirt! I took it to Ford and they told me one of the vacuum lines came off! I asked how that could happen and they gave me some story about how I could have run over something on the road ...BS...I had recently had the truck in for maintenance including tire rotation And they charged me $108 labor! short answer: look under the truck and make sure the vacuum lines are attached ... BEFORE you take it to the dealer!

:ranton
Yea but what's weird with mine is it doesn't function the 1st time, but I can turn the truck of and then back on and then it will switch into 4H or 4L.
 

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Aimless Wanderer
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929 Posts
Yea but what's weird with mine is it doesn't function the 1st time, but I can turn the truck of and then back on and then it will switch into 4H or 4L.
You quite possibly have a bad actuator switch either where you interact, or the solenoid valve(s) that route vacuum to the servos to engage the 4X4. Cold weather brings these little problems to the surface as the switchgear ages and, (in a lot of cases) the assembly grease dries/hardens.
 

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Junior Member
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6 Posts
Discussion Starter #7
So would you all say this is a EASY DIY?
 
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