2003 Ford Exp will not lock/unlock using my keyless remote or the button on my passenger door will lock but will not unlock. all other doors and tailgate door lock/unlock fine.

The RKE is controlled by the SJB - smart junction box ! Fords BCM - body control module .
Principles of Operation
Power Locks
The SJB controls the power lock/unlock feature of all of the vehicle doors, including the liftgate, to lock or unlock based on the input received from the door lock control switch, the keyless entry keypad or the remote keyless entry (RKE) transmitter. Power locking and unlocking of the doors function independently of the key position, vehicle speed or transmission position. The smart junction box (SJB) activates internal relays to supply the correct voltage and grounds for the door lock actuators.

Your best bet would be to take to ford dealer or some other qualified repair shop .
Remote Keyless Entry (RKE) Transmitter Lock/Unlock Control - Unlock
The RKE transmitter feature provides lock/unlock functions independently of key position, vehicle speed, or transmission position. The RKE transmitter feature provides a 2-step process for unlocking the doors. Upon receipt of the first request for unlocking the doors, the RKE control feature requests the SJB to unlock the driver door only. If another unlock request is received within 3 seconds of the first, the RKE transmitter feature requests the SJB to unlock all the doors. This feature can be changed to global unlock, so that all the doors unlock on the first press of the unlock button. To toggle between the 2-step unlock and the global unlock press the lock and the unlock button on the RKE transmitter at the same time and hold the buttons for 4 seconds. The turn signal lamps flash to confirm that the feature has been toggled.
Remote Keyless Entry (RKE) Transmitter Lock/Unlock Control - Lock
The RKE transmitter feature requests that all the doors be locked when the lock button is pressed. On any press of the lock button with all doors closed, the SJB provides 1 flash of the parking lamps. If any door is ajar, no flash occurs. As soon as the last door is closed, the SJB provides the flash of the parking lamps. If 2 presses of the lock button are received within 3 seconds, the horn chirps once, and the parking lamps flash twice to indicate that all the doors are closed and locked. If any door is ajar when the second lock request is received within 3 seconds of the first, the RKE transmitter feature requests the SJB chirp the horn twice without flashing the parking lamps to indicate it locked all the doors but 1 or more doors are ajar. When the key is in the ON or START position, the parking lamp flashes and horn chirp confirmations do not occur.

All locks not working ?????

• The doors do not lock/unlock using the remote keyless entry (RKE) transmitter

• RKE transmitter battery
• RKE transmitter
• RKE transmitter programming
• Aftermarket system
• SJB

• Go To Pinpoint Test H .

Check the relays in the fuse box. It appears that the solenoids for locking the doors are working correctly. However it appears that the lock solenoid is not working properly.

change the batteries in the remotes

The keyless entry system is controlled by the (GEM) - generic electronic module .
Keyless Entry The electronic door lock system has two main components:

• generic electronic module (GEM)(14B204)
• keyless entry remote transmitter (15K601)
• NOTE: Battery power and ground must be remove before disconnecting the GEM connectors to avoid setting false codes.
  Power Locks Operation The power locks feature allows the customer to lock and unlock the doors via momentary switches located on the driver and passenger door. When the GEM detects a momentary press of the driver or passenger lock button, the GEM will supply power to the driver or passenger lock actuators for approximately 250 ms from relays internal to the GEM. When the GEM detects a momentary press of the driver or passenger unlock button, the GEM will supply power to the driver or passenger unlock actuators for approximately 250 ms from relays internal to the GEM.
  Remote Keyless Entry Door Locks Operation The remote entry feature allows the customer to unlock the driver door, unlock all doors, and lock all doors using a valid remote transmitter as long as the ignition switch is not in RUN or START. The driver door is unlocked whenever the GEM detects a valid remote transmitter unlock transmission. All the doors are unlocked when the GEM detects a second valid remote transmitter unlock transmission within three seconds of the first transmission. All the doors are locked when the GEM detects a valid remote transmitter lock transmission. If the GEM detects a second valid remote transmitter lock transmission within three seconds of the first transmission, the doors will lock again, the horn will sound for 20 ms and the parking lamps will flash for 200 ms to indicate the doors are locked. If the GEM detects the driver or passenger door is ajar during the second lock transmission, the doors are locked again and the horn is sounded twice. If the GEM detects a valid remote transmitter lock transmission within three seconds of detecting a valid remote transmitter unlock transmission, the GEM will lock all the doors
• • The doors do not lock/unlock using the remote transmitter
  • Ignition switch.
  • GEM.
  • Remote transmitter.
  • Remote transmitter batteries.
  • GO to Pinpoint Test C .
  You followed the program instructions to the letter ? Programming -Keyless Entry Remote Transmitter NOTE: All keyless entry remote transmitters (15K601) must be programmed at the same time.
  NOTE: All previous transmitter identification codes (TIC's) will be erased when programming mode is entered.
  NOTE: To program (or reprogram) the keyless entry remote transmitters into the generic electronic module (GEM)(14B204), perform the following steps.
  
  1. Turn the ignition from OFF to RUN eight times within 10 seconds, ending in RUN. If the GEM has successfully entered program mode, it will lock and unlock all the doors.
  1. NOTE: The first TIC must be entered within 7.5 seconds of entering the program mode and additional TICs must be entered within 7.5 seconds of the first TIC. The programming mode is exited whenever the timing constraints are not met.
     Press any button on a keyless entry remote transmitter, and the doors will lock and then unlock to confirm that each keyless entry remote transmitter has been programmed.
  1. If the door locks do not respond for any keyless entry remote transmitter, wait for several seconds and press the button again.
  1. Turn the ignition switch to the OFF position, or wait up to five minutes after step 1, to exit program mode. If a keyless entry remote transmitter has been programmed (or reprogrammed), the GEM will lock and unlock all the doors one last time.
  1. Take an have the vehicle checked for DTC'S

B1396 Power Door Lock Circuit Short to Battery GEM GO to Pinpoint Test B . B1397 Power Door Unlock Circuit Short to Battery GEM

Hi.

To program ( or reprogram ) a keyless entry remote transmitter into the remote keyless entry module, perform the following steps:

1. Turn the key to ON or ACC and short the two terminals of the program connector, a two-pin connector located below the driver's side of the instrument panel at the base of the steering column. All doors should lock and then unlock.
2. Press any button on each keyless entry remote transmitter in turn. All doors should lock and then unlock. If the door locks do not respond, press the button again (up to three times maximum with the same keyless entry remote transmitter). If the door locks still fail to respond, go to Pinpoint Test A.
3. Repeat Step 2 to program additional keyless entry remote transmitters into the remote keyless entry module (up to four keyless entry remote transmitters maximum).
4. Turn key off.
5. Remove the short from the program connector. All doors should lock and then unlock.
6. Verify that the keyless entry remote transmitters have been successfully programmed by pressing the LOCK or UNLOCK button on each one, and observing that the system responds by locking and/or unlocking the doors.


I hope this helps you.

Thanks!

Programming Electronic Door Lock Control System NOTE: The electronic door lock control processor (14B001) erases all previous keyless entry remote transmitter (15K601) from memory when the keyless entry remote transmitters are programmed or reprogrammed. The electronic door lock control processor can store up to four keyless entry remote transmitters in memory.

• To program (or reprogram) keyless entry remote transmitter into the electronic door lock control processor, perform the following steps:

1. Turn ignition switch to the RUN position and momentarily short the two terminals of the program connector taped to the wire assembly and located behind the glove compartment. All doors should lock and then unlock. Remove shorting pin.
   

1. Press any button on keyless entry remote transmitter. All doors should lock and then unlock to verify the keyless entry remote transmitter has been programmed. If door locks do not respond, press button again (up to three times maximum with the same keyless entry remote transmitter).
   

1. Repeat the above step to program additional keyless entry remote transmitters into the electronic door lock control processor (up to four keyless entry remote transmitters maximum).
   

1. Turn ignition switch OFF. All doors should lock and then unlock.
   

1. Check operation.
   

1. Turn ignition from OFF to RUN 8 times within 10 seconds, with the 8th time ending in
RUN. Door locks will cycle to confirm programming mode.
2. Within 20 seconds press any button on first keyless remote. Door locks will cycle
to confirm programming.
3. Within 20 seconds, press any button on second keyless remote. Door locks will
cycle again to confirm programming.
4. Turn ignition to OFF. Locks will again cycle to indicate end of programming mode.

You need to take it an have scan tool method done .

check if it will work with the child locks engaged/disengaged if nothing the lock actuators may be worn out.