I have a 2000 c230, and also a mercedes star diagnosis system. The DAS unit will not read my car. I get a message stating the possible errors when trying to connect. The cables are loose and maybe circuit 30 and or 31 is faulty. I traced the pins 30 and 31 from the 38 pins socket das connection to some relays behind the fuses in the engine area. I have the part numbers of the relays: 0025421419(yellow), 0025420319(black), and 0025421119(green). I noticed that when number 0025421119 (green) is shaken it make a rattling noise. I dont know, do I need new relays? Can anyone help me with this problem so I can use my star diagnosis on my car. Thanks!!