Just be grateful that a key was available for your car. We 140 owners have no source for key-fobs any more. Benz stopped supplying them for no discernible reason. Luckily I have never lost a key because there is always a key holder thingy right inside the garage door where ALL car keys land.
Anziani

Finally heard from the dealer, I was away for a few days. Went down to pick up the new key, the service agent was looking for me, very attentive!

We went out to the car to check it out and presumably to close the service case.

He put it in, turned the key and - IT FAILED!
He tried a second and third time, it started a few times then again NADA!

And it was very hard to rotate in the socket (EIS) back to the far left to remove the key. It started the engine 4 or 5 times then FAILED.
So, we agreed the issue is some form of compatibility between the new key and the EIS, and he blamed the EIS, since there have been 2 new keys in succession that were flaky like this.

But why does the old key work 10% of the time - every time?
A close look and I see its slightly thinner than the new key fobs.

I give up, I'm not going the EIS route, I will use the new key as a spare in case I lose the old one.
Grrrrr

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

Originally Posted by rocky raccoon
When one of our 98 E320 FOBs stopped working, I sent it to this small company in Toronto area. He rebuilt it as new for C$50. (No need for our second working FOB to be sent or for programming).

Keys4Cars

Surely there must be a similar service in USA?

BTW : I once bought an MB and owner had lost the spare FOB. He ordered one from dealer. They need car when they program it - they connect to a server in Germany!) Cost him something over $300. Then he found the missing key

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Graham
85 300D,72 350SL, 98 E320, Outback 2.5

Very common for older software version EIS's to have issues with new keys......

I have used that vendor in canada when I visited some freinds in missisuaga, there was also an EIS repair service - if your EIS had failed. It was a different vendor though.

Its quite difficult to do in USA with advertisements as Mercedes Benz USA will come after the vendor. I know that the vendor has a special keyfob with a cable attached to it - he puts it in, and can pull the key hashes from it and write a key for the car. Its not as simple as it sounds though.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

The new keys dont work with the old EIS, and if you keep on using it - the car divorces the key and locks it out. To get around this - you will need a private locksmith to find you an oldstyle NEC or motorola key and write that.

in other countries - locksmiths buy the chinese made motorola key and write that for W210 - they work good with exception of radio range for lock unlock buttons - but that was the complaint even when these cars were new.

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2012 BMW X5 (Beef + Granite suspension model)

1995 E300D - The original humming machine (consumed by Flood 2017)
2000 E320 - The evolution (consumed by flood 2017)

why on earth would MB let the dealer sell keys that aren't suitable for the EIS? that sounds like a nightmare to try communicating it back up the foodchain to Stuttgart
I am happy using the old key and I'll put the new one away and just say its for emergency purposes, ha! I sure don't plan on making it a throwaway . . .

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!

MB dont want you driving an old car around, and w210 are getting quite old too.

The old EIS is pretty unique and the keys were quite expensive too, MB do have a solution for us old w210 owners though. They will happily sell us a new EIS for 1200 usd.. the type that works with new keys only

and to that I say:
┌∩┐(◣_◢)┌∩┐

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'95 E320 Wagon my favorite road car. '99 E300D wolf in sheeps body, '87 300D Sportline suspension, '79 300TD w/ 617.952 engine at 367,750 and counting!