You look like an MB expert --- here is a problem that I am having that has stumped my local dealer --- any thoughts? I posted this today but have not received any input yet. Thanks

The remote door key for my 2003 C230 Coupe can open and close the doors only when the remote is placed close (3 feet) to the driver door. I replaced the key battery but that didn't help. The dealer tried his key and agrees that there must be an antenna problem or something similar. Also, the AM radio seems to have a disconnected antenna. Only strong signals can be received. This problem popped up at the same time as the door problem. Is there a connection between the remote antenna and the AM radio antenna in this model?? Anybody know where the door remote and AM radio antennas are located in this model?

JimC
2003 C230
2004 Audi A4 Avant