Really hard case of the "P lock malfunction" error

Hello,
I'm helpless with this issue because I'm trying to solve that for about 2 months. To begin, I have bought a Prius 3 2011 from Spain (it worked as a taxi there) with 580 000km mileage. I drove it for a month without any problem - the suspension is as new, HV battery also (confirmed with a test), and the engine has a real 140 000km mileage only (it was replaced). You might think its a totally new car with just worn seats but it's not that easy... When I bought it in Poland we had approx 0*C temperature (winter), but when it risen up to 10*C my car started to make sometimes (but not every night) problems after a night break. It shows the "P lock malfunction error", vehicle doesn't go to a "ready" state but at first turning it off and on (just by the "start" button) solved the problem. The problem was getting worse, and at this point, despite the temperatures of 25 * C during the day and 10 * C at night, there was nothing to remove the defect.

I tried replacing the 12v battery several times (every had approx 12.6V and was 1-3 years old), and then I decided to send it to a qualified mechanic but he also didn't find the solution. At the beginning he was getting random symptoms but then the car decided to work without any problem during the daily tests for a week...


I got the car back, but after 4 days it got broken again. I tried myself disconnecting the white connector from the fuse box under the hood, replacing the transmission control module to a different pieces from a different suppliers (mostly named 89535-75010 because I read that they are dedicated to those Priuses, but also 89535-76010, 89535-76011, 89535-12010). I noticed that without the transmission control module, the car shows the same error but additionally "Inspect hybrid system" what allows me to think that the module has a communication with the main computer. None of installed for a test computers worked, one of them (randomly, one was ) allowed to switch between P and N mode - it's strange. They were exactly 89535-12010 dismantled from an Auris 2014 and second one caused the P icon blinking but without any other effect (89535-76011 from Prius Plus).

During those tests done by myself (approx 50 attempts) I have found a temporary solution - when the problem occurs, just unplug the "original" computer for a few seconds and plug it in again (by the way, it has 89535-76010 model). It worked all the time for a week... Now I have tried everything again with no effect. I'm really surprised that the car doesn't react predictably - today when it happened, it didn't even switch to a P position on the Auris computer as mentioned above.

I got the information from the mechanic that he followed the official Toyota instruction with no effect, I would want to do it on my own to make sure, but I don't have such experience in electronics (my hobby is phone and computer repair, not car modules).

The Obd2 scan shows the C2300 error every time it happens and P0862 when I disconnect the transmission module to reset it (simultaneously the "Inspect hybrid system" error shows).

I have uploaded the photos of my transmission module (the connector seems to be resoldered what is strange), is there any chance to have it modified by an unexperienced person? I don't have any thoughts actually, the car is working random...

Thank you for your help!

 

Which one exactly?