2005 Dodge Caravan Power Door Locks

Electrical problem
2005 Dodge Caravan 6 cyl Front Wheel Drive Automatic 55K miles

Our 3-year-old Granny-Van has door lock feature that locks all (5) doors with a flick of switch at either front door near the power window switch. This morning as we parked at church, I noticed that this switch (either side) produced no action and the doors stayed unlocked all during church. On arriving home, I checked the system -- the remote buttons on the key make the lights flash and horn honk (as if the lock/unlock mechanism at each door is working) -- but not one door locks or unlocks with the remote or with the switch on the door. We can push down/lift up all the (4) buttons in the passenger area and can also turn the turn the key in the front door to lock/unlock the driver door.
I cannot find [all I have is owner's manual] any fuse labeled for door locks. What could be stopping the electric command to lock/unlock my doors?
We are worried as we cannot find a way to lock the tailgate -- the key opens the gate, but doesn't turn the other way [as if] to lock the tailgate.