A car key usually consist of three parts:

1. The remote control. 

2. A transponder chip.

3. A key blade.

For some vehicles there may be a seperate key and a seperate remote. In this case, the transponder chip is together with the key, not the remote. Here is an all-in-one key, the three parts are all together.

 

The below picture is what a key transponder chip looks like.

Ok, then How to make a duplicate car key?

Once you get a new key, you should the following steps:

1. Find a locksmith to cut the key blade for you.

2. Program the remote control. This is pretty simple for some vehicles, no professional knowledge needed. Here is a video guide about how to program a nissan remote control. Different car may have different procedure.

http://www.youtube.com/watch?v=xxOgxUr7D4U

3. Program the transponder chip. This may require some professional skills. Usually a key program tool is also required. Common key program tools are SBB key programmer, AK500, AD900 and AK300......

 

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