Dear community, I’ve been reading with you for a long time and have been able to draw a lot of valuable information from this forum. Thank you for sharing your expertise! However, I can’t get any further on my current question. But I’m short before: I’m Immo, am 35 years old and have been living in Garbsen near Hannover and have been repairing my cars for several years and have taught me most of it myself. For almost four years I’ve been driving a G 270 CDI from 2002 with 270.000 k m. (photo in the appendix with roof box for the holiday.) When I took over the car, there were a lot of things to do. I gradually accepted the problems and learned a lot. I am a big fan of heaters and it always bothered me that my G did not install any. Therefore I bought a universal TT-C and am now busy with the installation. The heating should be switched on via an LTE module. CAN and AI remain outside. So far it is also clear that only the A. I have already read from pin 23 or 26 on the climate control panel, but I only have 16 pins. I can see which cables leave the climate control panel in the schematics. But not what the unused pins are for. Or did I miss this in the WIS/ASRA? What are the possibilities to control the ventilation? In the appendix I put photos of the plugs and pins as well as the circuit diagram of the climate control panel. P.S.: What is this black flap for? chkabel? It does not appear in the schematic. I wish you a nice evening and hope for your help.