Anti-theft technology in newer cars has become more complicated, which has driven up the price of making a copy of your car key. Car keys now have a transponder chip in them that sends a specific code to an immobilizer inside your car's ignition. If the immobilizer never receives the signal, then the engine doesn't start.
This makes it significantly more difficult to hot-wire a car (since there's no way to send the code to the immobilizer), but the presence of a transponder chip makes copying a car key a more involved process. In order to find out how to make a copy of a car key with a transponder chip, read on to learn more about your available options and what they entail.
Programming the New Key Yourself
Some car manufacturers allow you to associate a new key with your car's computer on your own, which makes copying your car key quite inexpensive. Check your owner's manual to see if it has instructions for programming a new key. You can use either an aftermarket key blank or a key blank made by the manufacturer of your vehicle. Aftermarket key blanks are significantly less expensive, but there's a risk that they won't work with your car.
Whichever type of key blank you choose, you'll need to get it cut at an automotive locksmith shop. Many car keys are laser-cut, which requires expensive machinery that most home improvement stores don't have.
Once the key has been cut to fit your car, you'll need to look up the process for programming it to your car. In most cars, you start the ignition using your existing car key, hold a button on either the key or your dashboard and then insert the copy into your ignition in order to associate it with the car's computer. Once finished, you'll be able to use the copy just like your other keys.
Using an Automotive Locksmith
If your car doesn't allow you to add a new key by yourself, you'll probably have to go to an automotive locksmith in order to have a copy of your car key made. As above, you can use either an aftermarket key blank or a manufacturer's key blank as your copy. In this case, however, it's almost always best to choose a manufacturer's key blank due to the labor cost of having the new key programmed — you don't want to opt for an aftermarket key blank, pay the labor fees for programming and find out that the key blank doesn't work.
Once the key has been cut, the automotive locksmith will manually program your car's computer to accept the new key. This process requires looking up a code based on your car's VIN that allows the computer to be reprogrammed.
Going to the Dealership
Unfortunately, not all manufacturers share the code that allows your computer to be reprogrammed. If an automotive locksmith can't look it up, then they won't be able to make a copy of your car key. You'll typically encounter this problem with German cars since the manufacturers don't share that information.
In this case, your only option is to go to a dealership to have a copy of your car key made. This is the most expensive option by far, but it may be necessary. The dealership goes through the same process of cutting a new key and reprogramming the car's computer based on the code that they receive from the manufacturer. Aftermarket keys won't be an option from your dealership, which drives up the cost even more.
Overall, your best bet for creating a copy of your car key is to call an automotive locksmith shop and ask them about your options based on the make and model of your car. If you'd be able to add a new key to your car on your own, an automotive locksmith shop will often do it for free after you have your key cut (it takes very little time). Otherwise, they can program your computer to accept the new key manually. Going to the dealership to have a copy of your key made should be your last resort — it will be much more expensive than having a locksmith make a copy of your key.
For more information, contact a locksmith in your area.