If some door is not lock from the remote key this is a Guide to make first a Diagnosis and repair it.
All the locks have the same mechanism, they differ only if it is left right or the back door.
I will not describe how the doors lock Removal because there Guides who describe it :) :

You will need
a set of Torx drivers
Screwdriver & allen set (to remove the door panel.)
a dremel with a cutting wheel.

After remove the door lock mechanism you you can see the 6 pin connector.
The photo below is the 2 contacts which control the remote locking motor.
You can connect carefully 12 volts to τo hear the sound and vibration. polarity is not important if you redo lock it unlocks.


If the motor is running the problem located somewhere else, Usually in the door wiring loom, i have seen many cut wire between the door and the body inside the rubber.

If the motor no working you must cut with a Dremel as you see with red line in photo and remove the torx screw.


Carefully remove the motor, do not damage the plastic gear, use a small screwdriver.
As you will see, there are two contacts in the plastic (red arrows in photo) that give a 12v to the motor, You need to clean it, i use a contact cleaner but a alcohol is enough.

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Also you need to clean the contacts back on the motor, a trick is to use a needle to make the pins springs harder.

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Put the motor carefully back, now before you close it check if the motor working good using the door connector as you seen in this video.

Hope this helps:)