Hello all,

Approximately 3 months ago, I started having issues with my rear right door locking issue. The door could be locked but in most cases it could not be unlocked/opened. That was intermittent issue, I planned on changing the lock mechanism but haven't. In December last year my door unlocked and could not be locked anymore, when you open the door it was not registered as open in the dashboard. Another issue is that power window on that door stopped working at the same time, meaning that all electronic in that right rear door is dead.

I searched forums trying to find an answer, and found out that Skodas (1Z 20009 VRS diesel) have issues with broken wires in the booth between the hinges. I removed rubber booth and found isolating tape around wires, removed it and could not find any broken or damaged wire isolation. I pulled on the wires and could not find any of them are broken.

I haven't checked the fuses, from what I saw on net, there is no dedicated fuse only for the rear door electronics so that shouldn't be the issue.

I'm puzzled, what should I check next? What could be the problem? Has anyone had similar issues?

Thanks upfront!

40 minutes ago, bihskodu said:

when you open the door it was not registered as open in the dashboard.

If the wiring is all OK then this suggests the microswitch in the door lock isn't adjusted or working correctly.

2 hours ago, PetrolDave said:

If the wiring is all OK then this suggests the microswitch in the door lock isn't adjusted or working correctly.

Thanks for the reply. I would suggest the same thing, but I cannot lock the door, or control window. How can micro switch be responsible for window operation if the door in dashboard is stuck in closed position, but I can open the door.

Also, I would add that when I took the rubber booth from the cables, and removed the isolation tape, the wires were wet for some reason. I washed the car today but haven't opened the door during washing. 

That wetness suggests that the boots are not sealing onto the paintwork at one end or both. That's bad news because the connectors are not inherently waterproof. Examine mating face of loom connectors for corrosion when unplugged from the pillar connector. 

Edited 6 January, 20242 yr by Breezy_Pete

15 hours ago, Breezy_Pete said:

That wetness suggests that the boots are not sealing onto the paintwork at one end or both. That's bad news because the connectors are not inherently waterproof. Examine mating face of loom connectors for corrosion when unplugged from the pillar connector. 

Thanks, I have unplugged the rubber booth many times, and it was dry, but the cables were wet where they enter the door opening. I will check again and try to clean the connector pins inside pillar and in the connector, but I haven't seen any rust so far.

Regarding eletronic controller(module), is there any common controller for window and lock operation that's found inside door? I'm thinking maybe that module is faulty, or I lost the ground in the wiring somewhere and that's causing the whole door to be without power.

I will try to look at wiring diagrams later, if I get some time. 

If you do find corrosion it may look something like this (different connectors on your car):

 

2 hours ago, Breezy_Pete said:

I will try to look at wiring diagrams later, if I get some time. 

If you do find corrosion it may look something like this (different connectors on your car):

 

Thank you very much for the image. My connector looks like new, it's super clean, I opened it to check for pins, if some of them are missing somehow and they were clean inside, I haven't seen corrosion like on the image.

This could be a problem with the LIN data connection which links the front right and rear right door modules. It is a thin purple/yellow wire and might be damaged at the front door hinge area instead of the rear door. Pin 5 of the black 12-way connector at front, A-pillar connector. 

1 hour ago, Breezy_Pete said:

This could be a problem with the LIN data connection which links the front right and rear right door modules. It is a thin purple/yellow wire and might be damaged at the front door hinge area instead of the rear door. Pin 5 of the black 12-way connector at front, A-pillar connector. 

I was going to check those connectors next, this weekend. I found out that right front door is the main central locking for all doors and thought about checking that as well.

Solving this issue was quite frustrating and time consuming so I'm posting solution if it would help someone. My Octavia's (2007) rear left door has been partially dead since I bought the car. All bus controlled operations (central locking, power window remote control) didn't work. Fault code was

Address 09: Cent. Elect. Labels:. 3C0-937-049-23-H.lbl

01333 - Door Control Module; Rear Left (J388)

004 - No Signal/Communication

So I ordered a used rear left door control unit J388, but changing that didn't help at all. After that I measured a LIN-wire (purple/yellow) from front left door control unit to rear left door control unit and it was OK. Finally I figured out the reason for this issue: The previous owner had changed left FRONT door control unit and it was originally from three door car, maybe from VW Golf. The front control unit was coded without "Rear door installed" bit. I had to log in to "42: Door Elect, Driver" with VCDS and change the coding. Now rear door bus operations are working fine and the fault code in 09: Central electrics is gone.

Edited 25 June, 202525 Jun by Mikko992