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ESOF problems

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A few words of caution... on newer systems (sorry, can't remember the date break off-hand) the plate PIDs will all say (IIRC) "OPEN" when the system is "at rest". A change of state of the position sensor will temporarily display the actual plate states but they will shortly all revert to reading the same once again.

 

The next time you change out a gearmotor encoder, save the position sensor. These sensors rarely fail and can be used to prove out the wiring between position sensor and module by simply plugging it in and watching the PIDs as you move the sensor through its range - the sensor is the same for 2011 trucks.

 

When changing the position of the control switch on the instrument panel, allow time for the PVH signal to run it's course (approxomately 30 seconds is required).

 

MY 2011 saw the advent of the CVH hubs - a system that has been giving cold weather problems from the git-go. These apply constant vacuum to engage the locking hubs rather than the more familiar "click pen" operation of the earlier two hub designs.

 

I see both systems (PVH and CVH) as being largely misunderstood. At the outset, they appear a little "Rube Goldberg-ish" even though there is a simple and logical chain of events.

 

The operator moves the control switch to the desired position. The module checks the position sensor and, if the position is "coherent" and (in the case of a shift to low range) that any necessary enabler conditions are met. Once it "knows where it is", it will energize the appropriate relay (CW or CCW) and watch for the plates to change state. If the plates do not change state soon enough (another sorry, "soon enough" is, for me, an unknown quantity) it will de-energize the relay and then make four more attempts. Once the shift occurs the module will assume that the front axles are now turning at the same speed as the hubs and will energize the PVH or CVH solenoid to engage the hubs. If the shift does not occur, the system will stop trying to actuate a shift and will set a code(s).

 

Do not overlook the importance, if deemed necessary, of removing the encoder and using a 5/8ths or 16 mm wrench to operate the transfer case shift stub. If you are on a 4 post hoist, remember that there is a neutral between 4HI and 4LO.

 

To make wiring diagnosis painless and simple, use my sensor method to check the plate PIDs and, using a headlight or other similar load connected to the actual motor connections at the encoder, use output state control to activate either relay to test those circuits. Both we and the PPTs in the WSM conspire to add unnecessary complexity to diagnosing these systems.

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  • 5 years later...

Hey I got one

2015 F250 4x4 lifted. when get into it in morning 4x4 operates like it should. after driving for about 25-30 min when trying to shift into 4x4 the message on IC pops up and stays on (like you said its attempting 4 more times)  then wrench light comes on with check 4x4 and code P1867. First time shift motor was installed (checked circuits at the time pass) as usual service advisor didn't get full info cause unable to duplicate at that time. any was it came back and t case was replaced. still does the same thing. if you let truck sit for a little bit it operates correctly again.

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