I have a 2000 C 280 with around 55000 miles on it. yday (after the rain) i started the car and suddenly there was a loud, loud beep beep from inside the car. I checked the dashboard and nothing was wrong, no orange lights nothing, the car was running smoothly and i tried to drive it and it drove very well, as usual, but the loud beep kept blaring away. It stops when I turn off the engine, the loud beep is heard as soon as I turn the ignition key on, even before I start the car. I called MB and the technician on the phone said he hadn't seen or heard of anything like this in his life! the alarm was so so so loud that it sounds like a fire truck alarm.

i seems to come from the right side of the passenger door? i am now thinking is it coming thru the speaker as I cannot believe such a loud beep can be from a sensor that MB put it, any suggestions?

Dan
California

 

the alarm siren with battery was on the driver's side (left). that can't be it.

try to find out where it's coming from.

 

I have this exact problem on my C-280. I didn't see where anyone came up with a solution. Anyone know how to correct this?