4x4 problems

I am the original owner of a 2005 6.0 and have never had any major problems with this truck. I bought a SCTx3 Tuner about a year ago and ever since then my truck has never seemed the same. I do not want to blame the chip because my truck is approaching 106k miles, which really isn't that many...

My truck is trying to go into 4x4 low while driving . it has the electric 4x4 switch. i have tried unpluging it and it stops trying to go in 4x4 low but sometimes switches into 4x4 high and i have to plug the switch back in and go in 4low to 4high then it will go back to 2wd and i have to unplug...