service four wheel drive HELP!

[midmohoe]

my 04 tahoe service 4wd light keeps coming on i have tried two different switches on the dash that does not fix it some times when i start it its in neutral sometimes 4 hi sometimes 2wd is there a way to reset the switch or any one had a problem like this thanks

 

[oak510_tahoe]

might be the encoder motor, I purchased one, but have not replaced it yet, but my truck has the service 4wd and sometimes it disables my stability control.