Proton: hmm....... I'm very much guessing, but I am aware that the Akustische Rueckmeldung Signalhorn channel setting in my instructions can be problematic if any part of the anti-theft alarm facility is active. I think that the assumption is that if the anti-theft alarm is operating, a siren is fitted to the car (hence the Akustische Rueckmeldung Signalhorn channel setting should be not active)

There are a bunch of adaptation channels in the BCM (@ address hex09) related to the anti theft facility - they contain the term "anti theft device" and "DWA" (it's German for DiebstahlWarnAnlage which means car-alarm).

Just a suggestion, but have a look through your BCM admap and check is any of these channels have a setting of "active"

Don