Try this IF YOU HAVE 3 BUTTON REMOTE WITH RADIO FREQUENCY REMOTE CONTROL (you don't say which year car is!!!). If you don't have RFRC then it won't do it!
1. Insert key and turn to position 2 (dash lights illuminate but do not crank engine) 4 times within 6 seconds
2. Switch off ignition. A tone should sound to indicate programming is possible
3. Press any button on the fob
4. Switch ignition back on as in 1.
5. Key fob should now work.
If you want to do other keys you MUST remember to do ALL the key fobs at point 3
Ray Peate
April 2007