4 wheel selection

[03z71chevy]

I had the exact same symptoms as well as mine once putting itself in 4hi while driving. I solved this by doing exactly what SLCHOE suggested. I replaced the sensor in the encoder motor using a new GM part that I found on ebay for around $80. I did this over a year ago and have never had a problem with it.

It is not hard to replace. Here is an excellent step by step write up that I used.

http://www.fullsizechevy.com/forum/...-encoder-motor-sensor-replacement-w-pics.html

 

[cooljunk]

To update this thread, I finally solved the problem for good. Installed a Transfer Case Motor Encoder Ring. Using this Youtube vid.

Did manage to change it without removing the front driveshaft, a bit of a job. No need to reprogram, it worked fine.