What is the reason for the unresponsive rear door window switch on the Bora?

[AmyDella]

The unresponsive rear door window switch on the Bora is due to a window regulator malfunction. Fault inspection method: Use a specialized diagnostic tool VAS5052A to check. The central electrical control unit stores a fault code: 03020, indicating a local data line circuit electrical fault. Reading the window switch data stream in the central electrical control unit J519 reveals that the open or close operation signal of the window switch cannot be recognized when operating the window switch. Window regulator malfunction solution: First, remove the door panel, then lower the window to the disassembly position (a hole in the bracket plate can be seen), take out the fixed glass rubber grommets, separate them from the lifting bracket, remove the glass bracket, take out the large glass, loosen the screws of the middle glass guide rail, pull the guide rail downward after loosening the screws, and then pull out the small glass.