solenoid

Does anybody have trouble-shooting suggestions for this with my 2010 5.4 L? Flipping the knob into 4L or 4H results in a "CHECK 4x4" message displaying in the IC, but no other indicator lights illuminated. Torque doesn't show any DTCs. There's no grinding sounds. The transfer-case motor is new...

Wanted to provide an update to others that may experience this issue. I've posted previously and seen others commenting about abnormal buzzing / droning noise from rear shocks. I believed it to be the solenoid and that was ford service advisor's opinion (seen it before) when I dropped off. Now...