Originally Posted by ror0
You don't say whether the key blades, holders or both are bad. The holders have some sort of internal sensor that must be within several inches of the associated proper key to allow it to work. The proper key blade by itself won't start the car. My dealership had to send my keys back to Germany for programming when I had a new ignition put in. They said that there is no way to get this done locally: apparently this is a MB security feature.
If you buy a spare key and holder on ebay, you will have a programming headache! Notice that none of the sellers ever guarantees that these keys will work in your car.
That's only if you don't have another key already, for example if you lost both keys... if you have one I think you can use it to program the one you just recently purchased via ebay... providing that you have the key blade cut... or replaced from an older key... again I could be wrong, but up until now I thought that is exactly how it works...
I just had a spare key made for a porsche cayenne turbo, and they did the programming here in the states at a local dealership it took about half hour... I wanted to do it myself, but did not find much information and just paid $60 at their rate for them to do it... it did not come preprogrammed nor was it shipped anywhere for programming... I would think that a key configuration on an older benz would be much less complicated than a new porsche... and if the local dealer can do it... in 30 minutes it must not be too hard to do yourself...