Your car may / mayt not have a connector Block B in the quadlock harness. Thus Pin 7 on Block B has to be connected to Pin 13 on Block A. On Comand power for the amp comes out of Pin 7 on Block B. Problem is that on Audio 20 is powered by Pin 13 on Block A ( grey black wire ) and this Pin 13 on Comand NTG 2.5 is blank so power not getting through and hence the amplifier remains dead. The radio amplifier needs power ( +12v) to allow radio reception. My comand unit fitted was from a 2009 model ( with SD card ) I believe the later, facelift models, 2009 onwards need SCN coding to activate comand / camera retrofit. Got a reverse camera fitted and working also with the rear tail gate lining removed, again DAS activated it without SCN coding. This powerline has to be fed through the rubber wiring sheath on the top of the tailgate. I could not find suitable power in the rear tail gate as they are switched with lights etc.
Problem is the rear cigarette lighter only powers up on full ignition so the radio looses reception when in key position 1 or 0. The comand radio now works perfectly with reception for all stations on FM. I cut back a bit of the red insulation on the single wire going into the antenna amplifier and wrapped the power line ( from cigarette lighter ) around it to power up the antenna.
power from the rear cigarette lighter on right hand side and placed an inline 5amp fuse on the line. Single red wire (power) going in one side with red and black on the other side connected to glass implanted antenna. I removed the tailgate to locate the antenna amplifier, mounted above the glass at the top. The Comand set up does not power the antenna amplifier located inside the rear tailgate and thus no radio reception at all. This coding worked offline and did not require a SCN code. I used Star / DAS to code the unit to get past the anti theft warning. Hi, Fitted Comand NTG2.5 to 2008 M元20 (W164) originally factory fitted with Audio20.