Dodge Ram 1500 2017: Error code 1646

My story goes like this. I had installed on my car a device that was taking the turn signal from red back lights and putting it to the reverse lights. That electronic device got burned, and I decided to take it out. After a lot of work, reinstalling everything to the initial state of the car, now I get a message of "back right turn light out" even though, on eye check everything on outside works just fine. No LEDs are out. When reading error with OBD 2 gives me 1646 error code - constant present, without any possibility of resetting it.

​I've read that, this kind of error is for a lot of other issues. For example if the passenger side mirror does not work, and other malfunctions. I've checked the backlights myself, all good, no LEDs are out, I even switched the lamps between them, the error is still there, the same message.
I run out of ideas, since I do not have a circuit diagram to read the whole schematic...

Any ideas from you guys what can it be?