I have a 2003 Suburban with 4wd. The service message came up on the odo display but the manual says to turn the truck off, if it doesn't come back don't worry about it. That is kinda weird. The message goes away after the truck is restarted.

Also, the 4wd selector will change from 2wd to Auto 4wd, hi, or lo 4wd after the truck is shut off and you turn it on again. So I am driving in 2wd, go to the store and get back in the truck with it in 4 hi or whatever.

Any ideas on what is or could be going on?

Thanks,

 

in my 97 i had kinda the same problem truck would not come outta 4wd unless i pulled the t-case fuse it ended up being the 4wd front actuator

 

It sounds like the encoder motor, mine has had the same message since the first week I owned it, but my problem is the switch. Mine just acts a little stubborn at times and won't go in right away when the button is pressed. If the t-case is changing around by itself though, it sounds like the motor is malfunctioning.

 

The problem is your 4x4 selector switch. Very common, and not too expensive.