Hello my name is Steve W, has anything been tried yet, shift motor etc?
Here is a TSB for this vehicle, I have replaced alot of these shift motors for inoperative 4x4's. A self test should be run with a scan tool to see the P1867 code is stored. You can always try tapping on the motor with a hammer and see if it starts to work again, if so replace shift motor.
TSB click here
Any more questions just ask, Thanks Steve W