I have a 2000 C-280. Upon turning the key fully on, or starting the car, an extremely loud "Beep" comes from under the passengers dash. Very irritating. I began pulling fuses until I found fuse 8 in the trunk labeled "Telephone System (opt). The beep stopped but an ABS light shows up on the dash. Fuse 8 must also have othr functions. Believing it is related to the telephone, I pulled the trunk mat up to reveal the Motorola system. It is very extensive--- technology has come a long way since 2000. Anyway, haven't been able to find how to eliminate the beep without impacting other systems. Any ideas would be appreciated.

 

look for a speaker under the dash on the pasenger side. you might have to remove the plastic panel up under the dash. you might find an external speaker. just see if thats where your beep is coming from then cut or disconnect the wire.