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DIY: New Chrome key upgrade/retrofit.

132K views 151 replies 58 participants last post by  revmb 
#1 · (Edited)
I want to post this DIY where everyone can see, but don't see a dedicated DIY sub forum, so here it is.

This mod is to swap the ROM chip from the old plastic key to the new style chrome key, the result is a functional chrome key that will take place of the old key; you will not gain an additional key. This will also work on other MB models, not just W209.

The key I use is from the 2006-2009 models with the round panic button. Ebay keys will work, just need to ask the seller if the key was tested and working, most of the ebay keys have cracks on the button, so ask and pay close attention to the pictures.



WARNING!!!!!! Do this at your own risk, not recommended if you have only one key and/or not have the proper tools and skills.

UPDATE 4/24/11: This mod does not work straight up for the keyless-go fob because the PCB configuration is not the same. I hope to figure it out soon. Will keep posted.

The procedure is as followed:

1. Open up your old key just as you would when you replace the batteries, do the same thing with the new chrome key, they are built the same way.
2. Pull out the PCB from the casing. On the old key, the board comes out easily by tapping the casing on your hand as you would do with a ketchup bottle. For the new chrome key, use a needle nose pliers grab on to the white plastic part and pull the board out.
3. Locate and remove the 30 pin ICs both PCBs, they look identical so make sure you mark the working IC from the old key. This is where skills and proper equipments are critical, you must not damage the boards or the chips. Also note the polarity/orientation of the IC, can be identified by a dot at one of the corners.
4. Install the old chip on the new board, make sure the chip is orientated correctly or it will not function, again special skill is required.
5. Clean up with electronics cleaner and dry your board completely with a hair dryer. Don't worry, you will not burn the board as long as you keep the hair dryer at least 8 inches from the board.
6. Reassemble and enjoy your new shiny chrome key.

This picture shows the chip from each PCB is swapped.





ATTENTION !!!! DO NOT BUY THE 2010 NEW STYLE KEY.

Regarding the new 2010 and up key style with the triangular panic button.
I opened one up today and was very disappointed as there is no interchangeable chip in this key to match up with the old key.
Apparently, MB had upgraded the PCB configuration, it is much simpler now with NO ROM chip that I can see.
Also, the casing is glued together so by the time you took it apart it will be in pieces; I had to use the ultrasonic tank to loosen the glue.
Damn MB engineers!!!!
 
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#140 ·
Hello, I can't PM because of my post count, so I have to post in here.

I have the all black key fob with the round panic button and want to convert it to the chrome key fob. I want one in great condition (like new) if you have one. Also, What is the turnaround time? I only have one key, so If I 2-day ship it to you would you be able to 2-day it back same day as you receive it?

Thanks
 
#139 ·
I received my key back from Dave last Friday and am incredibly pleased with the quality of the work and the service Dave provided. Dave is easy to work with, professional, and you cant beat the price. I cant remember the last time I heard my steering unlock as quickly as it did after receiving my repaired key from Dave. I highly recommend anyone with a broken or even potentially damaged to contact Dave and I will probably be sending him my old but functioning key for him to upgrade.
 
#143 ·
Hello, I just received my key back from David p. I was so relieved to find that it works 100% my turn around time was extremely fast. I am so glad I reached out to him and he came through for me. If I was to do this swap again I would definitely go back to David he hooked me up.

On a side note I am debating getting the key redone the chrome key I have is a different size than the old one. I'm sure it can be done. Thanks again for the awesome service and perfect communication!
 
#146 ·
Dead chrome key, damaged plastic key


Hello long time lurker, just joined bc of a key issue. Hopefully I am not late to this party but I see a lot of happy members in this thread lot of happy members with the work you have done. Our car has both a chrome key (3.0) and a black keyfob (2.0). We always used the chrome key but now it no longer works to start the car or unlock the doors even though batteries are good and red led lights up. The black keyfob works but is already damaged. I ordered a new functioning chrome key through the dealer which should arrive any day. If you are still doing this service, do you think you could get the black key internals to work in the chrome key case? Not sure if my old chrome key is hopeless now, even if it is would be interested in having black key --> chrome key conversion, like you have done before. Crossing my fingers that you are still doing this. Thank you! (Low post count and am unable to send a PM)
 
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