when i drive my mercedes 230, my emergecy brake light comes on whith an annoying sound. i did not engage the emergency brake. what is wrong?

 

Sounds LOL like your parking brake is still applied although you believe it to be off.
Are the rear brakes warm after a period of driving?
What's your gas consumption like. Worse than it used to be?
Need to inspect rear (parking) brake and linkage.

Stuart