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Does anyone have verified part number(s) for the whole remote KEYLESS-GO and manual key replacement? I'm coming up with different part numbers, and it appears that the electronic portion of the KEYLESS-GO does not come with the physical "manual" key.
Regarding the manual key, I come across several part numbers, 6-7-81-0217, 203-766-50-06, 000-766-09-00; the latter two of which you must acquire directly at a local Mercedes Dealer. Do these come pre-cut, or just blanks? The latter two parts appear to indicate one is blank and one is cut due to the one part number being twice the cost of the other.
For the remote FOB itself, this is the part number that comes up during searches: 204-905-11-04-9999
Last week I got in my car with the remote in my pocket as usual and when I pressed the start button, the car balked with the message "No Key Found." A couple moments of heart attack inducing anxiety and frantic staccato action on the start button, I pulled the key out of my pocket, placed it on the console and it started right up when I pressed the start button on a wing and a prayer.
If you haven't deduced by now, the car came with only one key.
Anywho, subsequent to that event, the cluster now warns me to replace the remote key battery. which I will do promptly when I return home from a trip.
Just call local dealers and tell them what you want. They will have different prices. You’ll have to appear in person with the car. Possibly proof of ownership. But you’ll be able to order the whole thing at once.
Last week I got in my car with the remote in my pocket as usual and when I pressed the start button, the car balked with the message "No Key Found." A couple moments of heart attack inducing anxiety and frantic staccato action on the start button, I pulled the key out of my pocket, placed it on the console and it started right up when I pressed the start button on a wing and a prayer.
You figured out the “dead fob battery” emergency start location.
You have the correct number for the key fob. Do not buy one from aftermarket sellers. Mercedes will refuse to certify a fob not obtained through their system.
I can’t verify the numbers for the physical key. In my experience, the physical key has to be cut. My dealer sent me to a specific locksmith with a note and instructions to get the new physical key cut after losing the original. It takes a machine that must be programmed with some sort of code.
Depending on the year of your car you might not get keyless go keys anymore. Pray it is just the battery. If not kiss your keyless start and comfort entry/exit bye-bye.
Keyless go keys are NLA. You cannot order them anymore. Mercedes' official statement is to order a non-keyless go key and just live with not using keyless-go anymore.
Plenty of aftermarket companies make clones of the keyless-go keys. Find yourself a well-rated locksmith that has experience working with Mercedes cars and they can get you an aftermarket Keyless-Go and program it for your car for you for a few hundred bucks. I recently had to go through this when I bought my C63 with only one key.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Try Northcoast Keyless for the fob. It comes with a blank key, which any locksmith with a laser cutter can duplicate. Programming the fob can also be done by a locksmith with a key programmer for model years 2014 and older. I had to replace a key on my 2015 SL400 last year, which uses the same fob, and the dealer was able to do it. They had the fob in stock. It ain't cheap, but cheaper than the alternative. Call around your area to find a locksmith that will program a 2014 Mercedes.
Northcoast seems to be out of the NEW fobs, and I cannot speak to the USED ones, but they do get new ones in from time to time. Get on their wail list. But for now, pay whatever you need to to get a second key.
You do not need to have the manual key to program or buy the fob. Mercedes dealers will order the manual key and it comes precut for your car. But that only gets you into the car or trunk -- you cannot start the car with it. By the way, a Mercedes dealer will likely not program a key fob you provide.
Last edited by JettaRed; Aug 13, 2025 at 08:45 PM.
You have the correct number for the key fob. Do not buy one from aftermarket sellers. Mercedes will refuse to certify a fob not obtained through their system.
The later posts by @0fc5dccf and @JettaRed indicate that things have changed in the last 3 years, making this advice obsolete.
Ugh... This is depressing if Mercedes has discontinued offering new key FOBs. I may still call a couple locals to verify, but wow. I know all manufacturers eventually discontinue producing and offering parts as older vehicles age out, but certain critical essentials like key FOBs I believe should still be offered for much longer as modern cars generally last much longer.
On a general side-note, I noticed a LOT of parts have been discontinued for the W204. I need a couple interior pieces and discovered them no longer produced. Luckily, I saw a couple NOS on eBay, which is now going to be my go-to source for parts.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
I will say that NorthCoast Keyless is good about refunding your money if things don't work out. But finding a locksmith first is a good idea. Just because their fob doesn't work with Keyless Go doesn't mean it won't work. It just means that you may need to do it the old fashioned way.
I got a spare for my 2004 SL500 a couple of years ago. The dealer screwed up and ordered the non-Keyless Go fob. It still worked if you inserted it in the ignition. The dealer ordered the correct one for free since I already paid once. They let me keep both since they said they could not reprogram the wrong key. Which brings me to the question, if I could get a fob for a 2004 Mercedes in 2020, why can't you get a fob for a 2014 in 2025? Have you actually called a Mercedes dealership about getting a replacement?
Which brings me to the question, if I could get a fob for a 2004 Mercedes in 2020, why can't you get a fob for a 2014 in 2025? Have you actually called a Mercedes dealership about getting a replacement?
Whether I can get a FOB in 2025 or not had not crossed my mind as I had assumed they are still available: my initial inquiry was what were the correct part numbers. I’m always trying to avoid the “stealership” prices by buying through discount OEM sources and my own DIY repairs.
it was the answers that suggested Mercedes is surprisingly no longer offering them. Haven’t called a local dealer yet to verify as I’m working out of town during the week and haven’t had the time.
Have you actually called a Mercedes dealership about getting a replacement?
Someone suggested exactly this in post #2 and it was ignored.
FWIW, the 3rd party ones are much lower quality than the original Benz ones and may give you issues sooner than a real key.
Best to get original key fixed if one dies. If you find a locksmith who programs them, ask if they can do original OEM keys vs. the $19.95 Amazon specials.
Used / previously programmed Mercedes keys cannot be reprogrammed. The firmware on the chip cannot be overwritten, and this generation Mercedes key uses a complex set of public and private key encryption between the EIS and the key.
XHorse has a very high quality aftermarket key that works with Keyless-Go and retains all of the functions. The XHorse key is actually very high quality and indistinguishable from the factory Mercedes key except for a red IR window at the tip instead of the black/dark red tip on the factory key.
Most locksmiths cannot program W204/W212 smart keys, it requires a specific setup with interfaces to the EIS and IR and RF communications with the key to setup the public and private key pair and write them into the tracks in the EIS.
Buying a used key is not a great idea to begin with, as each key has a limited number of times it can be used to lock/unlock/authenticate with the car. After it hits the limit, the key will not work anymore at which point you will need to program another key
The factory Mercedes Keyless-Go key for this generation W204/W212 is discontinued and is no longer available for purchase. You can still buy a non-Keyless-Go key and program that with Mercedes, but obviously you lose Keyless-Go with that key.
You can still buy the laser-cut mechanical key that slots into the smart key from Mercedes. It was $180 when I purchased it, requires proof of ownership and ID, and is only made and sent from one facility in Texas. Of course, any competent locksmith can make laser cut physical keys from VIN or from a another working key, but since my car came with the wrong physical keys that did not unlock the car I had Mercedes cut me two new physical blade keys, one of which I put into the XHorse replacement key.
Last edited by 0fc5dccf; Aug 18, 2025 at 04:27 PM.
2015 SL400 (M276 Turbo), 2014 C350 Sport (M276 NA), 2004 SL500 (M113), 2004 Audi TT225 (BEA)
Originally Posted by MacVidMB-V8
Someone suggested exactly this in post #2 and it was ignored.
FWIW, the 3rd party ones are much lower quality than the original Benz ones and may give you issues sooner than a real key.
Best to get original key fixed if one dies. If you find a locksmith who programs them, ask if they can do original OEM keys vs. the $19.95 Amazon specials.
You're right. I did read that but completely forgot.
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