Central locking malfunction!

Hello everyone!

I previously posted a question here about the location of the turbocharger connection on my car - a Passat 3B, manufactured in 07/97, with an AHU engine.
First, the interior light turned on in my car, and then the alarm system went off.
Since last night, the rear door (driver's side) has stopped locking. It only makes a buzzing sound twice, the door latch moves slightly, and then it stops -> triggering the alarm system.
You can still lock the door with a trick: simply open it and immediately close and lock it again.
This morning, I went to VW, and they told me that the control unit for the locking system is defective.
I then demonstrated the problem to them and showed them that the door could still be locked.
-> Shrugs and says: 'It's still the control unit, otherwise...'
Let's see.
Great sausages, I'll test them and I'll pay!
Cost estimate: €250 - €350.

I then removed the door panel so I could take a look at the locking mechanism.
'Just metal and wires behind it, nothing like the plastic film and hollow space you find in some other products...'
You won't be able to see the mechanism like that!
Is the vehicle armored?

Okay, I have a few questions.
How does the locking mechanism work on the 3B? It must somehow work electrically, right?
Where is the mechanism that retracts the door pin?
How do I get access to that?
I suspect there might be a problem there...
Where is the control unit located?
If it turns out to be the case after all...
If my alarm system also malfunctions:
Can the device be disconnected, and if so, where?

Thank you very much for your patience and effort!

Regards,
Andreas.

Hello,

Before considering a replacement, it's important to first read the error codes from the central locking system. The procedure the workshop uses, as you mentioned, is nothing new.
Okay, first, let's read the error codes. In case of emergency, the alarm system can also be deactivated.

Hello Michael!

I'll do it (or have it done), let's see what happens.

Thank you!

Andreas.

I once read somewhere that there are a total of 3 connections related to the door lock. In my case, I also occasionally experience errors when manually locking/unlocking, but never when using the remote central locking system! I'm therefore leaning towards one of my contacts...
Perhaps it's the same for you.

Regards,
Werner.