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Discussion Starter · #21 ·
I have a transfer case from an AWD Transit opened up on my bench right now. Got tired of so little information available from Ford so I bought one and disassembled it :). I can say with a high amount of confidence that the issue you had with the AWD system is 100% due to the AWD control module software and how it handles (...or in your case chokes on and errors out because of...) the incoming wheel speed data. The transfer case mechanicals internally are simple. The encoder motor that controls the front drive engagement is simple and provides the module with nothing other than a positional signal (there is no temperature sensing of the t-case or the encoder motor in the system). The "AWD" engagement is all handled by the module and the algorithms (which are different depending on the drive mode selected) and the math behind relative wheel speeds vs. throttle position vs. output shaft speed and any number of variables Ford has chosen to use. It's possible that the module itself has a temp sensing shutdown mechanism, after all it is engaging/disengaging a 20amp motor in real-time based on how the wheel speeds are interpreted. I could see the module heating up quickly if it was having to "work" a lot to manage the response to the drive mode algorithm but I don't see the motor having any issues because it doesn't actually see any significant load.
Awesome, i love people smarter than me. (lol) Thanks for the info, yeah as mentioned, im sure its this one little electronic doo hickie thats gumming up all of the works to save the system from implosion. What wires do i have to cut......... for the bypass. (lol)
 

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but i didnt go anywhere near even a 1/4 mile before it shut off.
What drive mode were you in and was traction control on or off?

I've found I can't get the van to behave/respond to throttle with TC on so I turn it off as soon as I hit dirt and things are much better.
 

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Do you have any pictures of where you got stuck? Would love to see what it took, so far my system has performed well in snow but I have not been in any sort of mud.. Also, do you have stock tires and any build weight or is it empty? I am learning a lot from this thread.. I would be pissed to see an error like you saw..
 

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I have a transfer case from an AWD Transit opened up on my bench right now. Got tired of so little information available from Ford so I bought one and disassembled it :). I can say with a high amount of confidence that the issue you had with the AWD system is 100% due to the AWD control module software and how it handles (...or in your case chokes on and errors out because of...) the incoming wheel speed data. The transfer case mechanicals internally are simple. The encoder motor that controls the front drive engagement is simple and provides the module with nothing other than a positional signal (there is no temperature sensing of the t-case or the encoder motor in the system). The "AWD" engagement is all handled by the module and the algorithms (which are different depending on the drive mode selected) and the math behind relative wheel speeds vs. throttle position vs. output shaft speed and any number of variables Ford has chosen to use. It's possible that the module itself has a temp sensing shutdown mechanism, after all it is engaging/disengaging a 20amp motor in real-time based on how the wheel speeds are interpreted. I could see the module heating up quickly if it was having to "work" a lot to manage the response to the drive mode algorithm but I don't see the motor having any issues because it doesn't actually see any significant load.
Thanks for sharing this "inside: view. So do you think since turning of LSD will reduce or eliminate the differential in wheel speed (I think) the likelihood of system shut down is due to high temp or other variables is reduced Excuse my ignorance, this is the first LSD or AWD vehicle I have owned (in 45 years of driving).
 

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Awesome, i love people smarter than me. (lol) Thanks for the info, yeah as mentioned, im sure its this one little electronic doo hickie thats gumming up all of the works to save the system from implosion. What wires do i have to cut......... for the bypass. (lol)
Cutting wires is not recommended:p

Part of my motivation for the work I'm doing is to asses the feasibility of adding a low range...which would have to be accompanied by an electronic "bypass" of some sort to keep the t-case "locked" into AWD and traction control off. It can be done from what I see...just has to be a decent demand for it.
 

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Discussion Starter · #26 ·
What drive mode were you in and was traction control on or off?

I've found I can't get the van to behave/respond to throttle with TC on so I turn it off as soon as I hit dirt and things are much better.
Well that is where im a little unclear. I was in Mudd/Rutts mode which i assumed was beast mode as it takes off TC automatically, but maybe it didnt at first and thats why i got stuck?

All in all, i think the system should have stayed on longer to give me more of a fighting chance to get unstuck. I didnt need much, but more than what it gave me. I dont see how the system could have over heated as well, i wasnt stuck for long enough to make it shut down on high temp. I think it was more of a speed sensor thing as mentioned in MGmetalworks post. Too much wheel spin must not like it and shuts the system down is all i can think?
 

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Discussion Starter · #27 ·
Do you have any pictures of where you got stuck? Would love to see what it took, so far my system has performed well in snow but I have not been in any sort of mud.. Also, do you have stock tires and any build weight or is it empty? I am learning a lot from this thread.. I would be pissed to see an error like you saw..
Sorry no pics handy of the hill that claimed me, but im there all of the time, so maybe next weekend i will try attempt number two to see how things go. (lol) Just need to make sure im in the "make it climb mode" next time as i couldnt find that yesterday. (lol)
 

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Thanks for sharing this "inside: view. So do you think since turning of LSD will reduce or eliminate the differential in wheel speed (I think) the likelihood of system shut down is due to high temp or other variables is reduced Excuse my ignorance, this is the first LSD or AWD vehicle I have owned (in 45 years of driving).
A LSD will reduce the variance in wheel speed for that axle (the rear in the case of the AWD Transit). The problem is, the Tcase module only handles engagement of the front driveline. The mainshaft of the Tcase is direct drive from the transmission to the rear differential with the front shaft being engaged/disengaged by the shift motor. Any differences in front vs rear wheel speeds are driving the "activity" of the AWD module.

I've come to the conclusion that this particular AWD system was probably the lowest cost system Ford could put together to meet a target. Not the best system for the van...the least expensive overall route for Ford to take. In my opinion, the system is too smart for its own good but too dumb to be awesome. The AWD vans are great in so many ways and I think they meet the needs of a very wide range of users but the software is just not at the same level as other Ford AWDs. Ford has the tools and experience to create incredible systems. For the Transit though, they really cheaped out. It wouldn't stop me from owning one. I think one just needs to be aware of the system's capabilities, strengths, weaknesses, etc...
 

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Cutting wires is not recommended:p

Part of my motivation for the work I'm doing is to asses the feasibility of adding a low range...which would have to be accompanied by an electronic "bypass" of some sort to keep the t-case "locked" into AWD and traction control off. It can be done from what I see...just has to be a decent demand for it.
Just being able to lock it would be beneficial, even without a low range. My wife's RAV4 has a button that does this, but it automatically unlocks at anything over a very slow speed.
 

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The first thing I do when on dirt or gravel is turn TCS off. Then, if I have tough or slippery terrain I engage Mud/Rut mode knowing I will be in low gear in that mode. Without turning TCS off it is impossible to feel in control over momentum or speed (for floating washboards, etc.) If for some reason I forget to turn off TCS the lack of throttle response reminds me very quickly. I think the other thing to keep in mind is that the brakes are a big part of these AWD systems and the ABS pump used to pressure the brakes may also have limits when there is a potential for a lot of wheel spin.
 

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Sorry no pics handy of the hill that claimed me, but im there all of the time, so maybe next weekend i will try attempt number two to see how things go. (lol) Just need to make sure im in the "make it climb mode" next time as i couldnt find that yesterday. (lol)
Here is a pic lifted from his buddy's FB post.
146500
 

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Discussion Starter · #32 ·
Here is a pic lifted from his buddy's FB post. View attachment 146500
Yeah thanks for the reminder. (lol) This pic is not the hill i got stuck on. This was the first hill i went up like it was flat ground, the 2nd one after this was the issue. This pic is of me backing all of the way down and they getting high centered on this snow bank and i couldnt go forward or backwards. Helpless feeling to be honest. If i was alone i would have had to walk home. (lol)

My next attempt will try everything that has been mentioned to do before i get stuck. Thanks guys.
 

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I have a transfer case from an AWD Transit opened up on my bench right now. Got tired of so little information available from Ford so I bought one and disassembled it :). I can say with a high amount of confidence that the issue you had with the AWD system is 100% due to the AWD control module software and how it handles (...or in your case chokes on and errors out because of...) the incoming wheel speed data. The transfer case mechanicals internally are simple. The encoder motor that controls the front drive engagement is simple and provides the module with nothing other than a positional signal (there is no temperature sensing of the t-case or the encoder motor in the system). The "AWD" engagement is all handled by the module and the algorithms (which are different depending on the drive mode selected) and the math behind relative wheel speeds vs. throttle position vs. output shaft speed and any number of variables Ford has chosen to use. It's possible that the module itself has a temp sensing shutdown mechanism, after all it is engaging/disengaging a 20amp motor in real-time based on how the wheel speeds are interpreted. I could see the module heating up quickly if it was having to "work" a lot to manage the response to the drive mode algorithm but I don't see the motor having any issues because it doesn't actually see any significant load.
Great info. Do you think there could be enough room inside that to engineer a Torsen center differential as a retrofit? They have been used to great effect on high output rally cars and are bullet proof even at >800 ftlb.
 

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I have a transfer case from an AWD Transit opened up on my bench right now. Got tired of so little information available from Ford so I bought one and disassembled it :). I can say with a high amount of confidence that the issue you had with the AWD system is 100% due to the AWD control module software and how it handles (...or in your case chokes on and errors out because of...) the incoming wheel speed data. The transfer case mechanicals internally are simple. The encoder motor that controls the front drive engagement is simple and provides the module with nothing other than a positional signal (there is no temperature sensing of the t-case or the encoder motor in the system). The "AWD" engagement is all handled by the module and the algorithms (which are different depending on the drive mode selected) and the math behind relative wheel speeds vs. throttle position vs. output shaft speed and any number of variables Ford has chosen to use. It's possible that the module itself has a temp sensing shutdown mechanism, after all it is engaging/disengaging a 20amp motor in real-time based on how the wheel speeds are interpreted. I could see the module heating up quickly if it was having to "work" a lot to manage the response to the drive mode algorithm but I don't see the motor having any issues because it doesn't actually see any significant load.
So maybe that software just needs an update?
 

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Yeah thanks for the reminder. (lol) This pic is not the hill i got stuck on. This was the first hill i went up like it was flat ground, the 2nd one after this was the issue. This pic is of me backing all of the way down and they getting high centered on this snow bank and i couldnt go forward or backwards. Helpless feeling to be honest. If i was alone i would have had to walk home. (lol)

My next attempt will try everything that has been mentioned to do before i get stuck. Thanks guys.
What tires?
 

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Surprisingly the European AWD Transits use a different system which is much more robust and will not get hot. You find a description here Transparent All-wheel-drive Ford Transit revealed at Hanover Commercial Vehicle Show and here
146537





146536

It is fully mechanical and uses essentially 2 Haldex type clutches locking the 2 frontwheels if needed. They can be kept locked with a switch. Obviously there are no other drive modes you can select because there are no electronics. You have to be careful though because once locked you also have the equivalent of a locked front differential. I used that system in my old van in Africa and Latin America and it worked reliably. In Africa I drove for dozens of miles in deep sand without problems. I am surprised Ford choose a different system in the US.
 

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Whole brain ford engineering goes through the costs to build a new AWD system with (new?) parts (at least new compared to the European version) instead of just taking what appears to be a proven design from the European version. Typical

So far happy with my AWD though. No deep snow or mud yet though
 

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Whole brain ford engineering goes through the costs to build a new AWD system with (new?) parts (at least new compared to the European version) instead of just taking what appears to be a proven design from the European version. Typical

So far happy with my AWD though. No deep snow or mud yet though
What’s funny is I was going through some past posts and someone posted they talked to a mechanic friend from Europe who said don’t get the AWD because it constantly breaks, lol.

Then people posted how the AWD system here is different etc....

You just can’t win today on the internet, everything is complete junk!!!, lol.
 

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Just about every European Ford that comes to the US gets downgraded. Their customers here are different. They want huge cupholders, smartphone integration, more paint colors and bigger tires so they can bump into curbs. We get crappy headlights, no diesels, more nanny systems, and no manual transmissions. Welcome to 'merica and don't forget to blame the federal government for all the problems.
 

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Great info. Do you think there could be enough room inside that to engineer a Torsen center differential as a retrofit? They have been used to great effect on high output rally cars and are bullet proof even at >800 ftlb.
Well... I don't think this would be the path of fewest Benjamin's but certainly anything is possible. If you really had the desire to have the Torsen center diff, you'd probably also have the desire to strengthen some other components and at that point you're designing and building an entirely new transfer case. Unlikely that a market for something like this exists. I don't think there is anything wrong with the front driveshaft engagement mechanism for the vast majority of the Transit users out there.

Could the AWD system components be improved? Yes. Would it be easy or cheap? No. I've designed and sourced several different custom drivetrain parts recently (internal and external splines, heat treated high strength steel, etc...) and I can tell you with absolute certainty that without dozens of buyers, the cost of custom t-case internals would be prohibitively expensive.

So maybe that software just needs an update?
Probably wouldn't hurt.
 
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