I recently bought a second hand BMW, 2002 3 series. I have now lost one of the two keys I got with it. I am nervous about the lost key being used to steal the car. I wanted to know if it is possible to get new keys with different coding so that the lost key can't be used and if so, approx how long does it take and how much does it cost? Any help is much appreciated. Many Thanks.
The cheapest way is to have the lost key wiped from the ecu so it cannot be used to start the car. It could still open any mechanical lock on a door or boot though.
The locks could be recombinated as well but this involves more labour to strip down the doors, ignition and locks. http://www.home-own.co.uk/ala/
bmw would charge you approx �300/400 to do what you want,where have you lost the key and what makes you think it could be used to steal the car.i think your being a bit paranoid about it.
You should be able to take the car to a BMW dealer, with all the keys you still have. They should be able to electronically switch off the missing key, ie it cannot be used to start the engine. However, the mechanical part could still be used to open the door, etc. Only sure way is a new lock set which comes with new electronic immobiliser code.