I have a '96 C220 and a couple days ago the red & green lights under the rear view mirror began flashing when I'd lock or unlock the doors with my key fob. The car locks & unlocks fine and has no problems while running.

I thought I read somewhere here that this indicated a security problem, but I can't find that post/thread anywhere.

I don't have a repair manual for this car so I'm onmy own. Any help would be appreciated.

Hello Randy : If both green and red flash at the same time for 30 secs change the batteries in key!
If they alternate green and red then there is no mobilization of engine control.
I would bet your batteries are not at 3volts each, Tim

Yes, they both flash at the same time for 30 seconds. Thanks for the clarification! Now I gotta figure out how to open the fob up and change the battery! LOL.