2005 Grand Caravan power door lock quit working. Side doors and rear cargo doors still open with keyless remote. Door lock "honks" when button pushed, but locks will not automatically lock/unlock.

The problem is most likely the switch/plunger .
You will need to take off the door panel and look inside, with an electrical tester, and see what has failed.
The switch/plungers are quite cheaply made, and fail often.
God bless your efforts.

your central control that control door lock may disconnected try check

Power Door Locks Circuit Description
The power door lock system incorporates door lock switches on both front doors and on the RH D-pillar, door lock motors in all passenger doors and in the RR cargo door, a door lock relay and a door lock control module.
Power for the door lock switches and the door lock control module is supplied from the CIG LTR fuse 13 through CKT 640 (ORN). Power for the door lock relay is supplied from the PWR ACCY circuit breaker through CKT 540 (ORN). Ground for the door lock relay is supplied from G202 through CKT 150 (BLK) and ground for the door lock control module is supplied from G400 through CKT 150 (BLK).
The door lock motors are reversible and both sides are connected to the normally closed contacts of the door lock relay. Those contacts of the relay are connected to G202. When any of the door lock switches are placed in the lock position, voltage is supplied through CKT 195 (LT BLU) to the relay lock coil. Since the other side of the lock coil is connected to ground, the coil is energized and it pulls the lock contacts closed. Voltage is then supplied through CKT 295 (GRY) to all the door lock motors and the doors lock. The unlock function operates in much the same manner except that when any of the switches are placed in the unlock position, voltage is supplied through CKT 194 (WHT) to the unlock coil of the relay and CKT 294 (TAN) supplies voltage to the apposite side of the door lock motor and the doors unlock.
Door Lock Control Module Description
The door lock control module is used on vehicles equipped with cargo doors. The purpose of the module is to lock the cargo doors after a lock cycle has been commanded from any of the door lock switches with the cargo doors open. When the RH cargo door is open, the module receives a ground signal from the closed contacts of the rear door jamb switch on CKT 1897 (ORN/BLK) to G400. When a lock command is received, the module retains this input until it receives an open input from the rear door jamb switch. Then the module sends a lock command through CKT 194 (WHT) to the door lock relay and the doors lock.
Rear Cargo Doors Description
The power door lock motor will not operate unless the rear cargo doors are fully closed. The power door lock motor is in the right cargo door. The contactors are on the rear cargo door opening on the body and on the right cargo door.

For Doors not getting open with remote or key problem,there are help links provided below.Click the link below to go through its procedure and troubleshoot the problem:----
drivers side front door will not open from inside or outside?

http://technoanswers.blogspot.com/2012/01/ford-f-350-crew-cab-drivers-side-front.html

----------

Car door will not close?
http://howtobyme.blogspot.com/2011/11/car-door-will-not-close.html

--------

All power door locks not working ?
http://howtobyme.blogspot.com/2011/11/all-power-door-locks-not-working-on_14.html

----------

Repairing car Door lock Actuator?
http://howtobyme.blogspot.com/2011/11/repairing-car-door-lock-actuator.html
---------------
How to Access car door panel?
http://howtobyme.blogspot.com/2011/11/how-to-access-car-door-panel.html

----------

Vehicle door panel components?

http://howtobyme.blogspot.com/2011/11/vehicle-door-panel-components.html

---------
Truck Door will not close?

http://schematicsdiagram.blogspot.com/2011/12/ford-truck-door-will-not-close.html

-----------
Where is Cars Door control Module located?

http://schematicsdiagram.blogspot.com/2011/12/where-is-cars-door-control-module.html

--------
Power door locks not working?

http://schematicsdiagram.blogspot.com/2011/12/power-door-locks-not-working.html

-----------
Door ajar light stays on?

http://technoanswers.blogspot.com/2012/01/door-ajar-light-stays-on.html

----------
Door locks not working?

http://technoanswers.blogspot.com/2012/01/door-locks-not-working-on-ford-explorer.html

----------
Front Door dis-assembly diagram?

http://repairhelpcenter.blogspot.in/2012/02/front-door-dis-assembly-diagram-for.html

---------
Rear Door dis-assembly diagram?

http://repairhelpcenter.blogspot.in/2012/02/rear-door-dis-assembly-diagram-for.html

--------
How to test Power door locks?

http://repairhelpcenter.blogspot.in/2012/02/how-to-test-power-door-locks.html

--------
Doors will not open with Remote?

http://schematicsdiagram.blogspot.in/2012/02/lexus-doors-will-not-open-with-remote.html

--------

How to replace Door Hatch ?
http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-hatch-on-acura-integra.html

---------

How to remove Doors?

http://repairhelpcenter.blogspot.com/2011/11/how-to-remove-doors-on-acura-integra.html

-------`-

How to Replace Doors?
http://repairhelpcenter.blogspot.com/2011/11/how-to-replace-doors-on-audi-a4-and-vw.html

--------

Remote will not unlock Rear door?
http://schematicsdiagram.blogspot.com/2011/12/remote-will-not-unlock-rear-door-on-gmc.html

--------

Door locks or windows not working on car?
http://schematicsdiagram.blogspot.com/2011/07/door-locks-or-windows-not-working-on.html

--------

This will help.

Thanks.

2004-2005 CARAVANS HAD A SOFTWARE ISSUE IN THE BODY CONTROLLER..REMOVING AND REINSTALLING IOD FUSE IN UNDERHOOD FUSEBLOCK..THERE IS A SOFTWARE UPDATE FOR THE BODY CONTROLLER FROM CHRYSLER..TAKES ABOUT AN HOUR TO COMPLETE..AS FAR AS I KNOW,THEY ARE ONLY ONES WHO CAN DO THIS

the door lock actuator is going bad.

please confirm the year and model.... also ... try and locate the relay for rear cargo door... it's likely failed. it would be either located in the fuse panel under the dash or the fuse panel in the engine compartment near the battery.

There is a flash for the body control module for this problem. You need to go to the dealership to get it performed though.

The problem is with the electric lock actuator, it will have to be replaced.