Just as i suspected. The flashing OD OFF light comes on as soon as I start the truck. Before I put it in gear. No driving or movement. Kind of like a hard code with the CEL. Except I don’t have a CEL on. Just the flashing OD OFF light. Does this give us any invite? I’m going to have my friend run the codes later today. He has some stupid expensive Snap On Scanner. So hopefully his will read the codes more accurately than mine.

 

I would check the solenoid connector pigtail on the passenger side of the transmission for any abrasion or melting as it’s right next to the exhaust. Also look real hard at the pins inside the connector to see if they are corroded. You can use a small mirror to inspect the solenoid plug itself and inspect it for the same damage. The pigtail can be checked easiest if you go over the top of the transmission and examine it from the drivers side.
If that all checks out look at the MLPS pigtail on the driver side for the same type of damage.
I would also put the truck in neutral and remove the linkage to the MLPS, it prys right off with a screwdriver, then take off the nut on the gear selector shaft and inspect that the neutral line marks on the MLPS are lined up. If gear selector metal tab moves while you are taking off the nut, all the way back towards the rear tire is park, all the way forward to the front tire is 1st.

Both of these are easy to check in under an hour. I had some pins on my solenoid pigtail that were corroded and causing some shifting issues. After I repaired the pigtail with a new one my issues went away.

 

It does! It tells me that something is wrong with the transmission system. It could be outside or inside the transmission. That's as specific as I can get without the codes.

 

I’m waiting for him to provide me the codes. Hopefully I. An have those soon.

 

OK, got the code. With the expensive wiz bang Snap On scanner. The only code is a P1728 (transmission slip error- converter clutch fault). No other codes. And with this code, the blinking OD OFF light comes on immediately when truck is started. No driving or moving of any kind. The code doesn’t appear to clear by cycling the key off and back on.

 

No code will clear by cycling the key off and back on.

There is at least one more code stored. The P1728 code cannot set immediately, so some other code is flashing the OD OFF light.To set the P1728 code the PCM has to measure slip when the torque converter is locked. It isn't locked when you first start, you have to be up to at least 35 MPH.

 

That is where my confusion is on this particular situation. Guys from the tranny shop and this forum, which are all way smarter than I am, are telling me the P1728 code will reset when the truck is cycled off and then back on and not come back until the computer senses a slip condition again. However, my truck is not acting that way. I know what I am being told is the case on most trucks, but mine is either an anomaly. Or there is something very odd going on. Because my scanner and the fancy Snap On scanner only read the P1728 code this time around. The first time I had a P1728 and an intermittent CPS code. I don’t remember the number of that code now. But it was there. I replaced the CPS and drove it for a while. Then only the P1728 code came back. I reset that again with my scanner and the code didn’t come back for almost two weeks. Now it’s back. Only the P1728 code is back. Keep in mind, that the OD OFF light once tripped, has always come back on as soon as I start the truck with just a P1728 code. If I reset the code with my scanner, then it doesn’t come back until a couple weeks of driving. During that driving time, I definitely hit speeds high enough to lock up the torque converter. My truck is definitely acting differently than what everyone says the computer should be doing. I have the blinking OD OFF light at start up no driving. With only a P1728 code. I can reset that code with my scanner. The truck drives fine for quite some time before it faults again.

I would think If it was electrical, the reset and drive until fault comes back wouldn’t be so consistent. But yet, this truck faults at start up with only a P1728 code. Which I’m being told is not how it works. But yet I’m seeing it do exactly that.

 

I think what you're NOT seeing is that the expensive Snap On scan tool is not reading all of the codes that are stored. I also think we have a mixup in terminology. When I say a code won't clear, I mean the code remains in memory. The flashing light WILL clear when the key is cycled, but the code remains in memory. If the fault isn't present at startup the light will not blink, but the code remains in memory. That's why I think there is another code that isn't getting read.

 

That does clear up some things. Since my light comes on immediately after start up, your saying there must be another code we aren’t seeing. Is there any means for me to see that code? I do have the AE scanner but haven’t used it yet. The truck is still at my buddies house. Do you think that would have a better chance at finding that other code?

But I must add, that the P1728 code is there right after startup. So it must be stored in memory like you mentioned.

Would the tranny shop have a better chance at seeing it? That’s why I don’t have the truck back yet is because my friend lives 5 minutes from the tranny shop. I could have him just take it back over to them with the light blinking this time. They couldn’t find anything wrong before but that was after I reset everything.

 

Somehow that hidden code needs to be found. I never used a Snap On scanner, so I am not familiar with their capabilities. The only one that I've used lately is Forscan, and it seems to get every code.

 

Sounds like there is just a hard code 1728 and once set cycling the key isn't resetting the light. The PCM sees it on start up and flashes the light. It seems you have found the issue, the torque converter starting to fail. I was never a Ford tech and not a transmission guy but I do know hard codes in PCM/ECMs will set the CEL on start up a soft code will store in memory until cleared but not trip the light on start up.

 

Sorry, but this post doesn't make any sense.

How would a P1728 set upon power up? The way the code sets is that the PCM looks for slip when the converter is commanded to lock. It is NEVER commanded to lock upon startup. The vehicle has to be up to a certain speed to lock the converter and run this test.

Just disregard Thaney423's post. He is wrong.

 

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Wow forgot you were the end all be all of everything E4OD. By the way had I followed your advice (on two different forums) regarding the issue I was having I'd still be hunting for a solution. Mark you are very helpful and wealth of knowledge but sometimes you're just not the only one who knows anything. My advise should be ignored but "there must be a hidden code that your scanner can't find" is sound advice? Goes right along with with your "there HAS to be a short in the system".