Doors Do Not Lock Or Unlock With Remote Transmitter

Turn ignition off. Remove power door lock relay, located at top of right side kick panel. Measure voltage between ground and power door lock relay connector White/Green wire. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, repair open on White/Green wire.
Turn ignition off. Disconnect Black REM connector and remove power door lock relay. Measure resistance of Green/Black wire between REM connector and relay connector. See Figure and Fig 1 . Resistance should be less than 5 ohms. Measure resistance of Green/Black wire between REM connector and ground. Resistance should be more than 10 k/ohms. If resistances are as specified, go to next step. If resistances are not as specified, repair Green/Black wire(s) as necessary.

Fig 1: Identifying Power Door Lock Relay Connector Terminals
Courtesy of FORD MOTOR CO.
Turn ignition off. Disconnect left and right power door lock actuators and power door lock relay. Measure resistance between power door lock relay connector Red and Green wires and corresponding wires on each power door lock actuator. Resistance should be less than 5 ohms. Measure resistance between power door lock relay connector Red and Green wires and ground. Resistance should be more than 10 k/ohms. If resistances are as specified, go to next step. If resistances are not as specified, repair Red or Green wire in question.
Turn ignition off. Disconnect left and right power door lock actuators, power door lock relay and REM. Measure resistance between REM connector Red and Green wires and corresponding wires on each power door lock actuator. If resistance is less than 5 ohms, go to next step.
CAUTION: DO NOT apply power and ground to power door lock actuators for more than 5 seconds as actuator may be damaged.
Turn ignition off. Reconnect left and right power door lock actuators. Leave power door lock relay and REM disconnected. Apply battery voltage to power door lock relay connector Green wire. Apply battery negative to REM connector Red and Red/White wires. Doors should lock. Apply battery negative to power door lock relay connector Green wire. Apply battery voltage to REM connector Red and Red/White wires. Doors should unlock. If door locks function as described, go to next step. If door locks do not function as described, replace door lock in question.
Turn ignition off. Reconnect REM connector. Leave power door lock relay disconnected. Measure voltage between ground and power door lock relay Green/Black wire while pressing LOCK button. Voltage should jump to about 10 volts and then return to about one volt. If voltages are as specified, go to next step. If voltages are not as specified, go to step 8).
Turn ignition off. Measure voltage between ground and REM connector Red/White wire while pressing UNLOCK button. Voltage should jump to about 10 volts and then return to about one volt. Measure voltage between ground and power door lock relay Green/Black wire while pressing LOCK button twice within 5 seconds. Voltage should jump to about 3 volts and then return to about one volt. If voltages are not as specified, go to next step. If voltages are as specified, transmitter and REM are operating properly. Retest for symptoms.
Turn ignition off. Disconnect and reconnect vehicle battery to reset system. Program transmitter. See REMOTE TRANSMITTER under PROGRAMMING. Repeat step 6). If voltages are now correct, replace transmitter. If voltage does not change, temporarily substitute known good REM and retest system.