Hi ,is it possible that the rear doors lock actuators stop working at the same time and should be both replaced or there might be other cause rather than the actuators it self?

If the door locks on your 2004 Chevy Aveo are continuously locking and unlocking even when the car is off or on, it could be due to a few different reasons. Here are some steps you can take to troubleshoot and fix the issue:

1. Check the battery: One possible cause of this issue is a weak or dying battery. If the battery is not providing enough power to the electrical system, it can cause the door locks to malfunction. Have the battery tested to ensure it is in good condition.
2. Check the door lock switch: The door lock switch may be stuck or malfunctioning, causing the locks to continuously activate. Try disconnecting the switch to see if the issue persists. If it stops, replace the switch.
3. Check the wiring: It's possible that there is a wiring issue that is causing the locks to malfunction. Inspect the wiring harness for any signs of damage or corrosion, and repair or replace any damaged wiring.
4. Check the door lock actuator: The door lock actuator may be malfunctioning, causing the locks to activate continuously. Test the actuator to see if it is functioning properly, and replace it if necessary.
5. Check the remote: If you have a remote for the door locks, it may be malfunctioning or sending signals unintentionally. Try removing the battery from the remote and see if the issue persists. If it stops, replace the remote.

If you are unsure about any of these steps, or if the issue persists after attempting to troubleshoot, it's best to take your car to a qualified mechanic for diagnosis and repairs.

If the driver door lock on your 2002 Ford Explorer is not working even after replacing the actuator, there could be a few other possible causes for this issue. Here are some things you can check:

1. Wiring and connections: Check the wiring and connections leading to the actuator to make sure they are in good condition and properly connected. A loose or damaged wire can prevent the actuator from working correctly.
2. Door latch assembly: The door latch assembly is responsible for locking and unlocking the door. If it is damaged or worn out, it can prevent the actuator from working properly. Check the latch assembly for any signs of damage or wear, and replace it if necessary.
3. Door lock cylinder: The door lock cylinder is the part of the lock mechanism that the key inserts into. If it is damaged or worn out, it can prevent the lock from working properly. Check the lock cylinder for any signs of damage or wear, and replace it if necessary.
4. Central locking system: The central locking system is responsible for controlling all of the door locks in the vehicle. If there is a problem with the central locking system, it can prevent the driver door lock from working properly. Check the system for any error codes, and repair or replace any faulty components as needed.

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.

None < LGM - liftgate control module inside the lift gate does .
Rear Wiper/Washer System Components
The rear wiper/washer system consists of the following components:
• Rear window wiper motor
• Rear washer pump
• Rear wash relay
• Rear wiper/washer switch
• RR WIPER Circuit Breaker 15A / ENDGLASS REG Circuit Breaker 30A
• WASH 20A fuse
• Body control module (BCM)
• Liftgate control module (LGM) / End gate module (EGM)

Your best bet , take it to a qualified repair shop. You have no idea of the complexity of these system's . Communication network between modules etc..... Could have DTC'S diagnostic trouble code's stored in the liftgate control module . An auto parts stores can not read these codes .

Power Door Lock Operation
The power door lock switches are integral components of the DDM and 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 monitors these inputs and sends a Class 2 message indicating a change in the switch's respective position. Modules which activate the power door lock motors receive the Class 2 message and activate the motor in the appropriate direction to lock or unlock the vehicle's doors and liftgate. The modules which activate the power lock motors are:
• DDM (driver door lock actuator).
• PDM (passenger front door lock actuator).
• BCM (both rear door lock actuators).
• LGM (liftgate door lock actuator).
The DDM, PDM and LGM 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.

From where , any switch ? driver door switch or either passenger door switch . This is a very complex system controlled by modules (microprocessors)
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The driver door switch assembly (DDSA)

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The driver door module (DDM)

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The passenger door module (PDM)

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The rear door module (RDM)

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The LH front power door lock switch

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The RH front power door lock switch

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The LH front door lock actuator

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The RH front door lock actuator

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The LH rear door lock actuator

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The RH rear door lock actuator

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The remote control door lock receiver (RCDLR)

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The power door serial data circuit

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The class 2 serial data circuit

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The DRVMDL Fuse - 10 amp

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The PDM Fuse - 10 amp

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The RRINMDL Fuse - 10 a
Class 2 and Power Door Serial Data Links
The class 2 and power door data circuits are both serial data links. The serial data circuits replace cables in the vehicle by multiplexing (time-sharing) data to and from each device over a single wire referenced to ground. If the power door serial data is lost, both the rear door module (RDM) and the passenger door module (PDM) enters the sleep mode. With the RDM and the PDM in sleep mode, no power door operations are possible.
Your best bet is to take it to the dealer or an ASE certified repair shop .

It is a common problem across many models of cars. The usual cause is failure of one or more lock actuators but this is unusual in a 2013 model vehicle that has probably not had a great deal of use. It is also unusual for 2 actuators to fault at the same time. In any event the interior door panels will need to be removed to inspect the actuators and the wiring.

If both door locks failed at exactly the same time I would seriously doubt the actuators are the cause. It is much more likely to be another issue such as a problem with the wiring to the doors on that side of the car. However it is not possible to identify the cause without removing the door panels and checking everything. (I think the dealership is basically honest when they tell you replacing the actuators may not solve the issue because until they check everything on the 2 doors with the problem they just will not know what the cause is.)

Normally there is only one fuse covering the entire central locking system and if the fuse blows you will loose power to all door locks not just 2 of them.

Jaguar 2000-06 - Locks & Lock Systems
Power Door Locks - Removal & Installation

Door Lock Switch
Door Lock Diagnosis & Testing

1. Visually inspect the following:
   Misaligned door(s), hood or luggage compartment lid Door latches Actuating rod Exterior door handle Interior door handle Door lock cylinder Cable Luggage compartment lid exterior release switch Fuse(s) Wiring harness Electrical connector Door lock actuator Remote transmitter batteries Vehicle battery Remote transmitter Door lock switch Front electronic module
2. If an obvious cause for an observed or reported concern is found, correct the cause (if possible) before proceeding to the next step.

Door Lock Motor
Coupe And Convertible

1. Turn ignition key to position II.
2. Motor door glass to fully raised position.
3. Turn ignition key to position O.
4. Disconnect the negative battery cable.
5. Remove door casing for access.
6. Remove door water shedder.
7. Position PVC secondary water shedder for access.
8. Slacken and remove the door glass rear runner lower securing screws.
9. Reposition door glass rear runner. Mark the position of the glass rear runner upper securing screw.
10. Slacken and remove the upper securing screw and move the runner away from the glass.
11. Disconnect door handle and lock barrel (driver door only) operating rods from latch links.
12. Slacken and remove the three latch assembly securing screws and position latch for access.
13. Remove latch motor harness multiplug from mounting bracket and disconnect multiplug.
14. Release operating cable from door handle. Move inner door handle to the locked position. Remove operating cable outer abutment from support bracket. Disconnect cable inner from door inner handle.
15. Remove lock motor assembly from door.
16. To install, reverse removal procedure.
    
    
    

    Fig. Removing door lock actuator
    

Sedan

1. Remove the door window glass
2. Detach the interior door handle.
3. Detach the actuator remote cable from the interior door handle.
4. Remove the interior door handle.
5. Detach the door window glass run.
6. Remove the exterior door handle retaining screws.
7. Remove the front door actuator retaining screws.
8. Reposition the front door actuator and exterior handle.
9. Remove the front door actuator and exterior handle.
10. Disconnect the front door actuator remote cable.
11. Detach the door lock cylinder connecting rod (1).
12. Detach the exterior door handle connecting rod (2).
13. Remove the front door actuator (3).
14. To install, reverse removal procedure.
    
    
    

    Fig. Removing door lock motor-Sedan
    

Hope this helps.

Doesn't lock or unlock ? These relay's are controlled by the BCM - body control module .
I have factory service repair information , 32 steps ! Too much info to post here .

Power Door Locks Inoperative (Rear Door(s))
2
Activate the door lock switches to the lock and unlock positions.
Do both rear passenger doors lock and unlock?
YES - Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems
NO - Go to Step 3
3
Is there only one door lock actuator that is inoperative?
YES - Go to Step 6
NO - Go to Step 4
4
Are the rear door lock actuators inoperative for both lock and unlock?
YES - Go to Step 8
NO - Go to Step 5
5
Do the rear door lock actuators lock?
YES - Go to Step 15
No - Go to Step 10
6
Disconnect the inoperative door lock actuator.
With a test lamp connected to a good ground, probe the door lock actuator lock circuit at the door lock actuator harness connector.
Activate a door lock switch to lock position.
Does the test lamp illuminate?
YES - Go to Step 7
NO - Go to Step 25

Some of these steps can be bypassed because you say they worked after replacing the relay .LOCK RELAY ? right .

7
With a test lamp connected to a good ground, probe the door lock actuator unlock circuit at the door lock actuator harness connector.
Activate a door lock switch to unlock position.
Does the test lamp illuminate?
YES - Go to Step 24
NO - Go to Step 26
8
Remove the rear door unlock relay.
Connect a test lamp to battery positive voltage.
Probe the door actuator unlock control circuit cavity in the left IP fuse block.
Does the test lamp illuminate?
YES - Go to Step 21
NO - Go to Step 9
9
Install the rear door unlock relay.
Remove the rear door lock relay.
Connect a test lamp to battery positive voltage.
Probe the door lock actuator lock control circuit cavity in the fuse block.
Does the test lamp illuminate?
YES - Go to Step 20
NO - Go to Step 22
10
Remove the rear door lock relay.
Connect a test lamp to a good ground.
Probe the battery positive voltage circuit (high current) cavity in the fuse block.
Does the test lamp illuminate?
YES - Go to Step 11
NO - Go to Step 22

If your not familiar with GM diagnostic flow chart's , they can be confusing .
Let me know if you need more diagnostic steps .

I just bought a 1999 Suburban and all of the door lock actuators were bad including the rear (barn style door) while I was replacing the rear door acuator I noticed that even with the factory mounting bracket on the actuator it was causing the door lock rod (the rod from the keyed cylinder lock to the actuator) was on a bind......the solution I came up with is adding an additional 3/4" spacer between the factory mount bracket and the door attach point. this solved any binding and the door lock works great now........also I used a lubricant on all the doors where the rods run through the plastic guides, which seemed to help quite a bit! Hope this help's.

This can be caused by the actuators in the lock mechanism failing usually causing the door to remain locked. The boor door can also fail this way, though sometimes the catch sticks (pry off the LR badge, squirt with WD40 and work it a few times to fix that). Replacement requires the whole lock unit to be replaced at a cost of roughly £60 a lock, and a hours work. Helps if you have small hands. It does require a complete strip down of the door, and will need the lock unit, trim panel clips, and a trim removal tool. Clips are a few quid, the tool's usually around a tenner.
For the rear door, this is slightly easier due to the lack of moveable glass, so you just need to get the rear panel off including sub and open it.
Try clicking unlock on your fob while pulling the latch inside. This may pop it open at the crucial point. If you put the child lock on, you're stuffed! I saw one at a breakers yard where they had to use a disc cutter to get the door open.