Hi Scotty. I have a 2004 GMC Yukon XL 5.3 with 260k miles. I love the truck, but (big shocker) it is…

eschrock

Hi Scotty. I have a 2004 GMC Yukon XL 5.3 with 260k miles. I love the truck, but (big shocker) it is having 4wd issues. It was in 2wd when I went to work. When I started the truck to leave, the 4wd Auto light was on. I pushed the 2hi button and it blinked for awhile and went to 4hi. It got stuck there and could not come out. I ended up removing the transfer case encoder motor and manually moved the adjuster on the transfer case to get it back into 2hi to be able to drive it. I then replaced the encoder ring inside the encoder motor (hoping a cheap fix would solve the problem). With the encoder motor out (but still plugged in), I tried pushing the 2hi button to see if it would move back to the appropriate position so that I could reinstall it. It gave an electric buzzing sound (twice, like trying to move), then moved and both 4hi and 4lo lights came on solid. Could not get it to move from there. I just unplugged it and am driving without it for the time being. Question is, what is your opinion, and how do I know if I have a bad encoder motor, front differential actuator, or transfer case control module? (fuses are all fine, push button switch has been replaced). Thanks a lot.