I have this issue where I can’t select 2wd or any 4x4 and I replaced the actuator, tccm, tcscs. When I use the scan tool I can manually switch it with the scan tool, but the control switch won’t do nothing. I have a U code it is u0401, idk if it might actually be that it fried a transistor or something inside the ecu but wanna verify everything I can before I go to the ecu.

Have you determined what module the PCM is receiving invalid data from?

Have you determined that the switch is okay?

I wouldn't go condemning the ECU before actually pinpointing the issue.