Passenger door lock wont unlock. power locks - 1994 Mercury Sable

Door Lock System Components
The power door lock system consists of the following components:
• Driver door module (DDM)
• Passenger door module (PDM)
• Door lock relay--Located in the instrument panel (I/P) fuse block and controls the locking of the rear doors.
• Door unlock relay--Located in the I/P fuse block and controls the unlocking of the rear doors
• Body control module (BCM)
• IP BEC
• Reversible door lock actuators in each door

Driver and Passenger Lock System Operation
The front power door lock switches are integral components of the driver door module (DDM) and passenger door module (PDM). The switches are two-position normally open rocker switches. When placed in either the lock or unlock positions, the switches provide a direct input to the DDM or PDM. The DDM or PDM monitor these inputs and send a LAN message indicating a change in the switch position. Modules, that activate the power door lock motors, receive the LAN message and activate the motor in the appropriate direction to lock or unlock the vehicle doors. The body control module (BCM) upon receipt of a lock or unlock signal will control the rear door lock or unlock relays and also send a LAN message to the DDM and PDM to perform the commanded function.
The modules that activate the power door lock motors are:
• DDM (driver door lock actuator)
• PDM (passenger front door lock actuator)
• BCM (both rear door lock actuators)
The DDM and PDM are directly connected to the respective door lock actuator through the door lock motor lock and unlock circuits. Once a door lock or unlock request has been received, the module will supply battery voltage to one side of the actuator and ground the other, causing the doors to lock or unlock.
The rear passenger doors are controlled by the BCM through the rear door lock/unlock relay which is incorporated onto the printed circuit board in the LH BEC. The BCM controls the unlock relay by providing ground to energize the coil and controls the lock relay by providing battery voltage to energize the relay coil. This energizes the relay and allows voltage to be applied to either the door lock motor lock or unlock circuits. Since the other side of the door lock actuator is connected to the normally closed contacts of the opposing relay to ground, the doors lock or unlock.

This usually works.
Take a rubber hammer,roll down the window,then manually unlock the door using the inside unlock button (not the power lock button) while you give the door a good whack about half way down where the door lock assembly holds the door closed to the car body.It may take a few whacks and a few lock/unlock cycles but this usually allows the lock to release and you can open the door.NOW.....take off the door panel and lube that lock assembly and don't close the door unless the lock can be locked and UNLOCKED.

DR/LCK fuse 25 amp . located in the I/P block
Fuse Block - I/P
In the right front kick panel

Power Door Locks System Components
The power lock system consists of the following components:
• Body control module (BCM)
• Driver door lock cylinder switch
• Front passenger door lock cylinder switch
• Driver door lock switch
• Front passenger door lock switch
• Door lock actuators in each of the doors
• DR LK Fuse 20-amp
Door Lock System Controls
The Power Door Lock System is controlled by the body control module (BCM) and can be activated by any one of the following:
• A door lock switch lock or unlock actuation
• A door lock cylinder switch unlock actuation
• A keyless entry transmitter actuation
• An automatic door lock actuation (Personalization function)
• An automatic door unlock actuation (Personalization function)
Door Lock Operation
When the body control module (BCM) detects a transition of either of the door lock switches to the lock position, it switches the door lock actuator lock control circuit to voltage. Since the lock actuator unlock control circuits are at ground potential within the BCM, the door lock actuator motors transition to the lock position.
Driver Door Unlock Operation
When the body control module (BCM) detects a transition of either of the door lock switches to the unlock position, it switches the driver door lock actuator unlock control circuit to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the left front (LF) door lock actuator motor transitions to the Unlock position.
The driver door lock actuator unlock control circuit is a dedicated control circuit used only for the driver door lock actuator motor. This is done so that the driver door may be unlocked by itself using a keyless entry transmitter or an automatic door unlock function (if programmed).
Passenger Door Unlock Operation
When the body control module (BCM) detects a transition of either of the door lock switches to the unlock position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the passenger door lock actuator motors transition to the unlock position.
The door lock actuator unlock control circuits are dedicated control circuits used only for the passenger door lock actuator motors. This is done so that the driver door may be unlocked separate from the passenger doors using a keyless entry transmitter or an automatic door unlock function (if programmed).

Check for broke wires inside the boot from body to driver door , this is a common problem . If you don't find broke wire's , pull the door panel to get at driver door switch . Check for voltage an ground circuit .
Rendezvous Door Lock System Components
The power door lock system consists of the following components:
?€¢
Body control module (BCM)

?€¢
Driver door lock switch

?€¢
Front passenger door lock switch

?€¢
Door lock actuators in each of the doors

?€¢
Door lock system fuse into the BCM (BCM D 25A fuse)

Door Lock Operation
When the BCM detects a transition of either of the door lock switches to the LOCK position, it switches the door lock actuator lock control circuit to voltage. Since the lock actuator unlock control circuits are at ground potential within the BCM, the door lock actuator motors transition to the Lock position.
Driver Door Unlock Operation
When the BCM detects a transition of either of the door lock switches to the UNLOCK position, it switches the driver door lock actuator unlock control circuit to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the LF door lock actuator motor transitions to the Unlock position.
The driver door lock actuator unlock control circuit is a dedicated control circuit used only for the driver door lock actuator motor. This is done so that the driver door may be unlocked by itself using a keyless entry transmitter or an automatic door unlock function (if programmed).
Passenger Door Unlock Operation
When the BCM detects a transition of either of the door lock switches to the UNLOCK position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the passenger door lock actuator motors transition to the Unlock position.
The door lock actuator unlock control circuits are dedicated control circuits used only for the passenger door lock actuator motors. This is done so that the driver door may be unlocked seperate from the passenger doors using a keyless entry transmitter or an automatic door unlock function (if programmed). This video on testing computer controlled door locks on a Subaru , doesn't matter . test yours same way > The BCM controls your door locks .
Are all of the power door locks inoperative from both door lock switches?

Pull the door panel apart and check and see if the pun that locks and unlocks the door is connected, if so check the power supply the the actuator.

You need to understand how they work , do you know about automotive electronic controls ? Your switches are just inputs to the BCM - body control module !
Door Locks Power and Ground
For door lock operation, the IP Fuse Block supplies battery positive voltage, through the 15 amp DR LK/TRUNK fuse, to the BCM. The BCM uses this circuit exclusively to apply power to the door lock actuators. The BCM is also supplied a ground circuit, which it uses exclusively to ground the door lock actuators. When a door lock is pulsed, the BCM internally connects these two circuits to the appropriate lock and unlock control circuits to actuate the locking or unlocking functions.
When diagnosing door lock malfunctions, these circuits must not be confused with the other battery voltage and ground circuits of the BCM. The appropriate wiring schematic must be used to locate the correct circuits. Failure to identify the correct battery voltage and ground circuits of the BCM during diagnosis of door lock concerns may result in misdiagnosis and unneccessary parts replacement.
Passenger Door Unlock Operation
When the BCM detects a transition of either of the door lock switches to the Unlock position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the passenger door lock actuators transition to the Unlock position.
The door lock actuator unlock control circuits are dedicated control circuits used only for the passenger door lock actuators. This is done so that the driver door may be unlocked individually before unlocking the passenger doors using a keyless entry transmitter or an automatic door unlock function, if programmed. When the keyless entry transmitter is used to unlock the passenger doors, the BCM requires a repeated unlock command before it performs the unlock function. However, when the unlock input is from a door lock switch, a single unlock command is all that is required to unlock all doors.

How to test computer controlled door locks

The locks on your vehicle are electronically controlled by the BCM - body control module . The driver an passenger door switche's are input's to the BCM . Do you know anything about automotive electronic's ? anti theft alarm remote, could this be part of the problem , No it's just a key less entry remote , nothing to do with the anti-theft .
Door Lock System Components
The Power Door Lock System consists of the following components:
• Body control module (BCM)
• Driver door lock switch
• Front passenger door lock switch
• Door lock actuators in each of the doors
• IBCM (PWR) 15-amp fuse

Door Lock System Controls
The Power Door Lock System is controlled by the body control module (BCM) and can be activated by any one of the following:
• A door lock switch Lock or Unlock actuation
• A keyless entry transmitter actuation
• An automatic door lock actuation
• An automatic door unlock actuation
• A last door closed locking (LDCL) actuation

Driver and Passenger Door Unlock Operation w/o Keyless Entry
When the body control module (BCM) detects a transition of either of the door lock switches to the Unlock position, it switches the door lock actuator unlock control circuits to voltage. Since the door lock actuator lock control circuit is at ground potential within the BCM, the driver passenger door lock actuators transition to the Unlock position.

Your best bet , take your vehicle to a qualified repair shop ! Need special tool to diagnose .

Power Door Locks Inoperative

Install a scan tool.
Turn ON the ignition, with the engine OFF.
With a scan tool, observe the door lock switch parameter in the Doors data list.
Does the scan tool display Idle?
YES - Go to Step 4
NO - Go to Step 8
4
Activate the driver door lock switch to the LOCK and UNLOCK positions.
Does the scan tool display Idle?
YES - Go to Step 9
NO - Go to Step 5
5
Activate the front passenger door lock switch to the LOCK and UNLOCK positions.
Does the scan tool display Idle?
YES - Go to Step 9
NO - Go to Step 6
6
With a scan tool, observe the driver door lock actuator command and the passenger door lock actuator command parameters in the Doors data list.
Activate a door lock switch to the LOCK and UNLOCK positions.

If the remote key fob locks and unlocks the doors then the problem is more than likely the power lock switches, this is a common problem on the Venture Van.

faulty master switch ..replace

looks like car has other issues as well.. but try that first

both the rear passenger side wont unlock ???? How many doors are on the passenger side ? Or both back doors don't unlock ? Two relays lock / unlock the back door's Not the lift gate . The BCM controls the relay's . The relay's are located in the rear fuse box . Under back seat .