My '96 C280 will not start after opening the driver's door with a manual key (do not have a smart key). When I turn the key in the ignition the Anti-theft lights on the rear view mirror flash. Sometimes if I get out of the car and relock and unlock it again with a different key it will start but yesterday it would not start with any of the keys I have (4 including valet). Tried disconnecting battery, nothing.Help!

 

I just went out to try it again. Unlocked, inserted key in ignition, turn light flashed....nothing. Then tried again and just pressed down on key and iginition cylinder moved alittle and presto started no problem. Tried this a few times and it started every time. So now is it a wire running from the ignition that is loose? I am a female owner (inherited my MB) but my husbands is very mechanically inclined....Any new thoughts?

 

Try locking/unlocking through the trunk tumber. It should unlock all doors. I believe that there is a DAS module that allows the drive authorization based on input from transponder in the key. It has been a while so i'm a bit rusty on this one. Sometimes the das modules have been known to lose programming and cause problems. I just can't remember if on this model. Try the trunk unlocking first though.