A little background, im new to this forum and new to chevys. I picked up a 2004 tahoe lt with 80k miles on it a few months ago. Its been a great rig so far but i keep getting "service 4wd" on the screen and i have replaced the switch and cleaned the grounds and checked every fuse in both fuse boxes and checked all connectors. It only does this about once a month and the 4wd gets engaged about 3 times a week and works fine but every now and then when i go back to 2wd this message pops up and and i cannot get it to shift out of 2wd. If i turn the key off and then back on everything works great. Im stumped on what else it could be i was going to replace the encoder motor on the transfer case but it was just replaced when we bought it. Does anyone have any ideas? Thanks.