2017 GMC Sierra 4x4 4WD Not Working, C0306, C0321, C0392, C0396, C0398, C039E, Needs Software Update 

Excellent video. One key element is you mentioned the system would function properly initially. Then after driving for a period of time shift function failed. Exactly what my 2017 is doing. Looks like I don;t need a transfer case replacement after all. You likely save me several thousand dollars in unnecessary transfer case replacement. Bravo

Also, I greatly appreciated your recording where I could hear the various sounds as u test drove the truck. Mine sounds exactly the same.

GOD HAS BLESS YOU THANK YOU ROBERT DOTTERER MY TEACHER ROBERT DOTTERER KNOWLEDGEABLE ROBERT DOTTERER HAPPY CHRISTMAS 🎄 THANKS 👍 FROM NICK AYIVOR FROM LONDON ENGLAND UK 🇬🇧

After weeks of searching for the cause and fix to the C0398-05 code my 2012 Avalanche is throwing, I found this. While it may be the encoder motor or range position switch or tccm Or any combination of them. This video looks close to what I’m experiencing. I can hear the encoder motor hunting but the truck is stuck in 4lo most times I start it up, or 4hi and sometimes, but rarely Auto 4wd. Never 2wd. I have the xtool A30M Bluetooth scanner. I’ve tried the learn option in the various modes- no luck. That actually made the transfer case lose control completely. How can I do what you did??