I just rebuilt this transmission and now am getting these codes, indicating an open circuit and issue with the EPC (electronc pressure control solenoid).

Other issues after the rebuild (throwing in for context in case they may help narrow down the issue):

• Car intermittently won't start in Park...have to shift to neutral. We did not move the range sensor module on the side of the transmission. Maybe some slight mis-alignment occured when removing/reinstalling the ;inkage but this is just popping the arm off the shift module and putting it back on, no adjustment should've occured.
• AC blowing HOT (not warm, HOT) - I wouldn't think this would be related, but I did read another post on some forum where they were getting these error codes and his AC also went out at the same time, so just throwing this in there.

This code did not happen before the rebuild, so I find it hard to believe that the solenoid itself has gone bad as a result. I've checked the external harness is securley seated into the transmission and have replaced the internal hard wiring harness.

As a next step was going to just replace the solenoid and trace continuity from external harness back to CPU. BUT, prior to the rebuild, I was getting P0720 errors, indicating sensor issues, that turned out to be a wild goose chase (problem was bad front drum seal which led to burnt clutches).

So, just wondering if there are other physical issues that would be a potential issue after a rebuild that would cause these codes related to the EPC? Any ideas welcomed!

 

Turns out the issue was due to the hard wiring harness with the receiver slots being spread too wide to make contact with the solenoid pins.

This likely happened during removal of the harness the first time.
I purchased a remanufactured one, which I didn't inspect thinking it was good, but one of its EPC receiver slots was really jacked up.

So after 2 harnesses not working I assumed it was the solenoid. But then I went under there with the key on, and wiggled/pushed on the harness where it mates to the solenoid and noticed a quiet, high pitched buzzing (kind of like a mosquito) when I pressed on it and stopped when I let off. So I pulled the remanufactured one off, went back to the original one, used a small flat blade screw driver to gently bend the receiver tangs closer to the middle to ensure contact with the solenoid pins. After reinstalling, again with the key on, I could here that high pitched buzzing sound consistently without applying any additional pressure.

Buttoned her backup, Bob's your Unlce, no more codes!

 

I literally just dealt with the exact same situation.. including P0720 when full transmission failed minus reverse.. 06' FX4 175k miles... sure would be nice if the PCM would put a CEL on prior to total failure.. not the first time **** has happened and no warning lights.. So yup chased in circles trying to find a short circuit for OSS.. did find melted wire sleeve which I pulled the entire Trans harness out after I pulled the tranny and put heat sleeve over it.. I rebuilt the transmission, put it back in and heart dropped when o/d and trans fault started flashing... then saw the codes and then this was the first post I saw.. went to the garbage can, grabbed original hard trans harness and sure **** codes are gone and transmission works..

 

Patience and perseverance are important when diagnosing and resolving vehicle maintenance problems, and your experience serves as an excellent example of how a systematic approach can lead to successful problem resolution. Moreover, this works everywhere, even in a casino. Here is information about https://casinosanalyzer.com/online-c...rde-escudo-cve Cabo Verde Escudo online casino by which you can find honest casinos. That's where you can check not only your luck, but also your calculations in different strategies. It's also a valuable lesson - always check remanufactured or replacement parts before installation, as there may be manufacturing defects or damage. Thanks for sharing your experience, and I hope your vehicle continues to run smoothly!

 

Right here................^^^^