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Key Compatibility and Programming?

2K views 1 reply 2 participants last post by  rudeney 
#1 ·
I searched but can’t find the exact answers. I bought a C320 wagon a couple weeks ago and only got one key. The case is cracked etc but it works. I want to get a new case and a spare key but as we all know they are expensive. All that being said here are my questions:

1) My car is a 2002 C320 Wagon with a 3 button remote (counting the panic button). Most of the remotes I see have a trunk release button that mine does not have. Can I use a case that has the trunk release button (4 button remote) and just swap the internals out?

2) Can I use one of the fancy chrome keys with my car? There are quite a few used ones out there very reasonably priced. I realize I would not have the correct metal key and it would have to be reprogrammed or guts swapped out but none the less can I?

3) Can these keys be reprogrammed by me? I have read the dealer has to do it. That being said can they reprogram one of the chrome keys or another used key like mine or 4 button to work on my car and what would I expect to pay for the reprogramming?

Thanks in advance of the help. Want to have my research done before I got to the dealer or buy a used key and or new case.
 
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#2 ·
1) My car is a 2002 C320 Wagon with a 3 button remote (counting the panic button). Most of the remotes I see have a trunk release button that mine does not have. Can I use a case that has the trunk release button (4 button remote) and just swap the internals out?
Yes, that should work. Obviously, the trunk button won't do anything. Swapping the internals is very easy - just remove the battery carrier and then use some small tweezers or needle nose pliers to gently pull the circuit board from the key case.

2) Can I use one of the fancy chrome keys with my car? There are quite a few used ones out there very reasonably priced. I realize I would not have the correct metal key and it would have to be reprogrammed or guts swapped out but none the less can I?
Your key's circuit board won't fit in the shell of the new chrome keys. If you order a new key from the dealer, it will be one of the new chrome keys. Yes, it will cost you around $200, but you need a spare!

I think a while ago, someone was selling (on eBay) an aftermarket key shell with the chrome trim that would accept the old-style plastic key internals, but I haven't seen this in a while. Also, there was someone here on the forum that would, for a fee, remove the chip from your plastic key and solder it onto a new chrome key.

3) Can these keys be reprogrammed by me? I have read the dealer has to do it. That being said can they reprogram one of the chrome keys or another used key like mine or 4 button to work on my car and what would I expect to pay for the reprogramming?
MBZ keys can only be programmed by MBZ corporate. Even dealers do not have the ability to program a key. A used key from another vehicle is of no use to you, except maybe for the plastic shell. Basically, your car's electronics were programmed at the factory for the 24 keys that it can accept over its lifetime. Basically, the car can have 8 active keys at a time, and of each of those 8, if it is lost, it can be superceded two more time (8 concurrent keys x 3 version = 24 total). Only MBZ corporate knows the actual codes and only they can create keys with the right codes.

When you order a new key from the dealer, the key comes from the factory pre-programmed for your car. There is really no need to schedule a service visit - just go to the parts counter and provide the VIN and proof of ownership. Now, since you are missing (at least) one key, if you wanted any missing keys to be deactivated, you would need to schedule a service visit, that way they can see which of the 24 key codes need to be deactivated.
 
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