I have a 2000 Blazer LS 4x4 with the Auto 4WD push button transfer case and on random start ups the Service 4WD light will turn on and the lights on the control module will turn off not letting me select anything..

Sometimes it will work sometimes it won't.

Any ideas on how I can fix this?

 

I'm having this same issue I hope someone can help. I read somewhere on here is could be the push button switch I changed that out and nothing changed. I might take it to the dealer and have them pull the codes if it doesn't cost an arm and a leg lol.