truck as usual and switched to reverse to back it out

I doubt the issue is the range sensor. This basically just tells the rest of the modules what gear the unit is in. The wrench light with no codes is a little odd.

How much time was between this happening and then checking for codes?

Maybe 3 minutes. It went off when put in drive. Now I do have an oil sending unit causing faulty low oil pressure....

Ah. That is interesting. If the truck is driving normally and doesn't have an issue, I would let it lie but fix that oil pressure sender because that could have definitely cause this.

Really? It would cause it to go into limp mode like that? Hm. Well, I replaced the sending unit tonight and cleaned the connector. I'll report back if it occurs again.

However is it normal if I select "3" on the gear shift that the truck won't move? I go to drive and it shifts fine, gears 1-6. Maybe it's too high of a gear to start from.

Never mind, it does move in 3 just takes a little more throttle to get it going.

Okay. Glad you figure that out because it should move but as you found it will not move very well. Clearly it is not meant to drive that way. I believe if it won't operate in a gear then it will block the shift, meaning it won't show the gear you are commanding. When you press the button it just won't shift.

As for the limp in, low oil pressure or perceived low will cause limp in because limp in is just simply a protection mode that is controlled by the PCM. If it sees low pressure or anything else that can cause damage to the engine or transmission, it will limit power.

Makes sense. Well does it make sense to see an increase in power after changing it? It wasn't leaking oil badly, just barely a drip here and there.

Sounds like a molded leadrame issue, which is hugely common on these trucks! Here is some food for thought.

Been almost a month since I had this problem. I changed out the oil pressure switch and it's been doing great. But this morning after cranking it up I immediately switched it to reverse and the "R" did not illuminate but it slammed into gear, and then I backed it up, switched to "N" and "D" which it also did not illuminate until it slammed in drive, which then the "D" illuminated and the wrench symbol went away. Still no codes on the ECM.

Bmdouble I looked into the Lead-frame. Looks like there is a recall on these and Ford now has an updated lead-frame and valve-body part you can buy for like $650.00. There is a rail type mechanism on the lead frame that selects the gears, and almost sounds like that could be my issue. I could not read the instructions you posted, they were very tiny. If possible, I would be interested in attempting to replace the valve body + lead frame with the updated parts.

Here is the process for the disassembling the valve body but if you want to replace it and the recall is calling for them to put a new lead frame on the existing valve-body, just tell the dealer that you want to pay for the new valve body and to put the parts on that one. They would be fine with that because it wouldn't matter which valve body they are installing, old one or new one. It is the same amount of work.

I don't see why they want you do disassemble the valve body. There are 8 long screws holding the entire assembly to the transmission, and then a few holding the lead frame to the valve body. The new lead frame comes with a row with new solenoids and everything.

They are looking to limit the cost of these repairs because this is actually not a recall. It is an extended warranty. That means it needs to fail for the reason stated in the document attached. A recall is something that they will replace the part no matter what. This is a case where it requires a failure for them to do it.

If you don't have these codes then I doubt they will perform the repair.

Yes I'm sure they won't. So I was going to do it. However, Ford said I could come by and get the computer updated for free.

Can someone help me confirm the part number for this assembly? I see that the part number is 7A100 on Ford.com, and they'll send you the most updated one. But the full part number is BL3Z-7A100-A, and on FordPartsGiant.com it says this is replaced by FL3Z-7A100-E. I assume this is the most recent part. Can anyone confirm that FL3Z-7A100-E is the most updated part? It's a couple hundred dollars cheaper. I know typing this number in on Ford.com or any other number containing 7A100 will just bring up the original page.

I show FL3Z-7A100-E is the most updated part. FordPartsGiant is pretty good with this. Plus I show they have the exact same cost on both parts. Most likely because you will not be able to order the older one. If you do, they will just send you the updated part.

Hope this helps. If you still question it, just call a Ford dealer and give them your VIN and they can pull the part number per the VIN. This is the most accurate way.

Finally! I was able to snag a code when the wrench symbol came on. P0705. Is this definitely what needs to be replaced? Again, the wrench symbol disappears and all is well when I start moving in Drive.

That is interesting. It is range sensor code. I attached the testing that needs to be done for this one. It could be the sensor but I would suggest running through the testing just to prove out wiring and the PCM.