Control Module Power Supply

Battery voltage +30
30 voltage is fed via fuse 23 (22a) to control module pin 15.

Battery voltage +54
+54 voltage is fed via fuse 21 (22a) to control module pin 1. The control module is activated by +54 voltage.

Diagnostics
When +30 voltage is absent, it is only possible to operate the front side windows up and down and the rear side windows up. None of the other functions controlled by the STC control module can be operated.
When +54 voltage is absent, none of the functions controlled by the STC control module can be operated.