Can keyfobs be reprogrammed at home?

[pcman_jh]

I see folk selling ignition keyfobs on eBay - the keyfobs that are the plastic type with infrared/electronic control and without the traditional metal key areas. I have them for my '99 E300.

Can these be bought off eBay and programmed by yourself or are you buying a white elephant as they need to be coded by the Merc garage?

If they have to be done by the Merc garage, would Merc do them if you didn't buy it from them directly?

Just asking as there are a few on sale and it would be nice to pick one up as a spare if they can be programmed reasonably cheaply.

 

[Blobcat]

There have been quite a few posts on this subject, once programmed they cannot be changed. For obvious reasons really. Only option is from MB, just make sure your sat down when they tell you the price.
The ones on Ebay are of no use, no matter what the vendor says

 

[M6AJJ]

I can confirm that once the key has been programmed to a vehicle, it cannot be re programmed, even by a dealer.

 

[mioba]

ususally people want to replace the keyfob because the unluck button is split (very common on these)
Can you not just get a cheap fob off ebay, and replace the internals, if thats why you want a new fob.

I am bit weary about dealers saying they cant be reprogrammed. I purchased a used w220 and one of the fobs was split, I demanded a replacemt and they sorted it within a day.
So maybe they can reprogrammed but they dont want to let theier customers know (a trade secret type of thing, or to keep a market for thes fobs, or to deter thieves).
I think the best way to find out would be if you knew someone on the inside.

IMHO