Not sure why, but when I lock and unlock my car (07 C280) using the key remote, the car's not doing it's usual beep/chirp sound. The car is still locking, the lights are flashing, just no sound. Any ideas out there on what could have happened and how I can resolve? Thanks in advance.

 

Did you put the car in valet mode by accident? Refer to your manual for more info.

 

Mine went silent too but it wasn't disabled in the dashboard menu. My alarm horn (siren) went dead. Mercedes charged me like $75 to replace it.