Which continent or country are you from?
There is no coding, just replace it. Google search with 64118390122
for example from Germany http://www.ebay.de/itm/Steuergeraet-...-/110737947519
part number 64118367951 superseeded part number 64118390122.
UK, check the plugs if same http://www.ebay.co.uk/itm/BMW-E34-HV...-/171557110577
Or a remanufactured one by Programa, then you are sure it works http://www.programainc.com/bmw/clima...118367951.html