When I crank my 2001 Chevy Blazer it starts in four wheel drive high.. the four wheel drive low button does nothing at all ... But I can press the four wheel Auto button it goes into gear but then will not come out two wheel drive buttons doesn't respond at all either.. I'm new at working on Chevys and four wheel drives in general but would really like to get my four wheel drive system in order as I'm rather fond of my blazer...

 

i want to say this sounds like a bad switch. you have 2 separate buttons that do not function? no indicator lights lit or flashing on the switch?


EDIT: realized this was in the new member section which is only for introductions, moved to 2nd gen tech

 

Suggest trying a free and easy "fix" by reflowing the solder joints on the 4x4 switch. Involves removing the switch from dash, separating the two halves, and of course reflowing the solder joints, mainly on the connector.

From the description, sounds the the TCCM is working, but is getting incorrect commands from the 4x4 switch.

Worth a try.