Note: This doesn't cover key fob remotes, but general consensus appears to be - don't buy second hand key fobs as you won't get them working, and will be a waste of money.
Note2: My Experience here only covers the C5, I don't expect other cars that have a similar setup to be really any different.
As above this covers getting a spare key without any bells and whistles, generally a key that you'd hope never needs to be used, but is there ready in case it does.
What you'll need:
- Your 4 Character IMMO Code from you confidential card that you should have gotten with your car (in all likelihood a previous owner removed it and never passed it on!). If you don't have it, you may be able to get it for free from your dealer, or other places online by jumping through a number of hoops, but will not go into that here.
- The mechanical key code (about 7 digits), or take a clear digital photograph of your existing key.
- Access to a Lexia, either your own or hopefully find someone nearby who can help.
I got my key from http://www.carkeyhelp.co.uk, specificallly this one. There are other sites such as http://www.gallalock.com, but I found their site to be a bit confusing on the key cutting side.
I took a photo on my digital camera, had the key sitting on my wallet, with macro mode on, and diverting the flash with some folded paper (to provide enough light, but not get glare off the key), I didn't have the luxury of sunlight at the time, but the days are getting longer so you might be able to do away with the flash altogether.
Uploaded the image on the form, put in the year of my car, requested it with a transponder, and cut. Comes to £19.50, and I think delivery to the UK is about £1.50 (it was about £2.50 or so for me if I recall for getting it shipped to Sweden).
Then wait for the key to come.
Getting it paired to the car is fairly simple:
- Try the key in the door to unlock, to test the cut is fine. (if you have a remote fob, then before opening the door, press the unlock button to disable to the alarm)
- Connect up the lexia
- Go into Diagnostics - Global Test - BSI - Learning - Key Programming.
- Put in the 4 character IMMO code that you have.
- Follow on screen instructions for putting the keys in the ignition etc
- Resync any remote fobs
- Check you can start the car with the new key.
- Put Spare key in a safe place.