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Discussion Starter · #1 ·
I was recently running GDP tunes but my truck didn’t feel like it was running correctly so I bought SPE tunes. Has a DPF and EGR delete. The truck ran great the first day I had the tunes but now it feels like it’s running rough again. Right after installing the tune I got DTC U0100 and U0101. It doesn’t go into limp mode or anything but the code is always there. Talked to the company I use for tunes and they said it has to be a wiring issue unrelated to the tune. I didn’t have the codes prior to flashing and the truck still runs without going to limp mode. Do you think it is a tuner issue? I haven’t found any problems with the wiring yet.
 

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Ah, I'm not the only one that has run into this sort of problem! Same issues here when changing trans tunes. I had thought it was due to accidentally getting dielectric grease on the pins for the main wiring harnesses going into the ECM/TCM. I cleaned them multiple times with QD Electric parts cleaner. Currently I seem to only get one code, U0101 for the TCM. Now, I don't know which of the three wiring harnesses going into the ECM/TCM are for the TCM, but, one of the "lever clips" that holds them in place ( the one closest to the driver side) has a piece of the plastic that locks it in place cracked off so it no longer holds in place correctly, but I have a zip tie holding it at about the same position as the rest until I replace the actual clip. As for now, whenever I load a new tune, which has only been Trans Tunes, I only get the DTC for the TCM communication. Now with that said, I used to be able clear the DTC and the codes would almost immediately return, now after cleaning the pins and getting the clip as close to the same position as the rest, it only happens immediately after loading the Trans tune and once I clear the code one time, it does not return. So, I feel you're pain. Let me know if you figure anything else out.

Side note: I am only talking Trans tunes and you are dealing with what appears to be both Engine and Trans Tunes, so from my research on the trans side I came across information regarding checking your ground wires if the rest of the wiring is ok and if all that checks out, then the ECM/TCM will need to be tested. I am a garage mechanic, so take it for what its worth.
 

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Discussion Starter · #3 ·
Installed my old tunes from GDP and the codes went away. Then I reinstalled the SPE tunes and the codes haven't popped back up yet. Hopefully they don't come back up but I'm sure they will at some point. I'll probably clean off the wiring harnesses just in case it has something to do with that.
 

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Now, I don't know which of the three wiring harnesses going into the ECM/TCM are for the TCM, but, one of the "lever clips" that holds them in place ( the one closest to the driver side) has a piece of the plastic that locks it in place cracked off so it no longer holds in place correctly, but I have a zip tie holding it at about the same position as the rest until I replace the actual clip.
From what I recall about the PCM harness connections the connection that is to the driver's side seems to be emissions related only. I've found people selling a connector plug that covers the PCM port when running deleted.

Shibby Engineering FORDPCM PCM Harness Plug

 

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Discussion Starter · #5 ·
From what I recall about the PCM harness connections the connection that is to the driver's side seems to be emissions related only. I've found people selling a connector plug that covers the PCM port when running deleted.

Shibby Engineering FORDPCM PCM Harness Plug

I still haven't been able to find a solution. It only happens with my SPE tunes but the truck seems to be running fine. If the PCM and TCM were "disconected" then wouldn't the truck not run at all since theres nothing telling the injectors to fire?
 
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