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.