2003 Chevy Tahoe 03 Tahoe 4X4 problem REPOST

I will first apologize for the late response, I am not sure which transfer case you have? I haven't done an extensive search on what I believe your problem is, to answer your question "what the main thing is when driving in 2 wheel" , the transfer case shift control module sends a pulse width modulated (PWM) signal to an electronic motor, which is the transfer case encoder motor. This motor rotates the transfer case control actuator lever shaft, applying a clutch pack, I believe it is malfunctioning, which would cause the control actuator shaft to disengage the clutches into neutral, as you stated; "after a block or so the transfer case kicks into neutral" furthermore I am wondering how long you hold the button activated, the manual says you have to hold it for a least 10 seconds, that allows the electronic motor to fully engage. The four-wheel-drive is activated by a different servo that is probably why
you have to as you have stated; "i have to stop put the transmission in neutral then put it in auto 4 wheel to get to wherever im going." I hope I have answered your questions and if you have any more do not hesitate to contact me.