you have to remove two software lines from the Kombi (instrument panel )
to turn off the SOS monitor and unplug the TCU , Mulf 2 Hi that covers
that function.
This is accomplished using NCS expert from standard tools.
these two lines
TCM_ALIVE_MONITOR -> nicht_activ
TCM_ID_MONITOR -> nicht_activ
must have nicht added.
You need for your new head unit to support PDC check with the manufacturer of the head unit.
http://www.e90post.com/forums/showthread.php?t=805677
Also I think connects2 makes a harness that keeps pdc alive with aftermarket head units.