service 4 wheel drive

[signals34]

whats with this "service 4 wheel drive" keeps coming up every so often...i have a 2006 adventure...could this be a sensor ?..it seems as thought the axle lock button flashes when the warning comes on....all 4 wheel drive options work..not sure what to check...thanks !

 

[aspen]

rear locker is bad i had the same thing about 1, 000 to get replaced

 

[Jeepwalker]

Rear locker, or sensor/switch?