I have read many a post here about transfer cases locking up, some with the dash lights flashing, some not. Here is a first case scenario you need to address before dropping to your knees and looking towards the skies hoping somewhere in the clouds, a GM Tech will parachute down. When you’re out, this may just save your *** or at least get it home.
____Dash Switch Replacement - Not Transfer Case the Problem____
There is a switch in the dash behind the buttons for changing from 2x-4x-4x/low that has a TSB on it. I had this issue happen when out in Anza. I was first stuck in 4x/hi then it went into 4x/low then stopped moving. I put it into reverse and hit the 4x/hi and it went back into that but the lights were still flashing from 2x/hi -> 4x/low and I was jammed up and back in 4x/low. Rocking back and forth for a few mins it freed up and I was able to get it out of 4x4/low into 4x/hi. I shut her down feeling that it had to be a signal issue as I take too good care of my truck. I started by opening the hood and getting to the main fuse box. I first pulled the PCM then the PCM-B and E fuses as well as the ignition and a few others just to cover all bases. I pulled the Neg Battery cable off and waited. After 10 mins I started putting the fuses back in reverse order before putting the Neg Battery cable back on. It somehow bypassed the switch and the lights stopped flashing and I was able to get back into 2x/hi. I had it into Chevy the next day and they changed out a $35 switch and that was 60k ago. The dlrshps are aware of this problem with the 99-02 Silverado’s'. Now the rest of you know, changing that switch out is cheap, don't let it ruin your day. Never give up. Start pulling fuses, your hair, but Never give up.
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