Key reprogramming
 

Have read all posts regarding key reprogramming.
Needed to do that recently, as my key was not remotely locking/unlocking.
However, now, although the locking/unlocking operation is back to normal, the car will not start!
Is there any way to reprogram the immobilizer on the spot, without having to take the car to the dealer?
Thanks.

I don't believe the two functions are related. I just picked up a new key for my 2001 X5 and it came from BMW programmed to operate the vehicle but was not programmed to remotely unlock it. This required a quick programming by my indy which I observed while he performed. I did not see anything that could alter the programming of the key to start the vehicle.

My thought is there is something else wrong. Perhaps the key is starting to fail? Do you have an alternate key you can try? I purchased a new key not only because I received a single key when I purchased the vehicle but also because the vehicle intermittently would not turn over unless I performed an off-on cycle of the ignition. Since I've used the new key I have not experienced this behavior (though it's only been a week and a half).

To summarize the key could be the problem.

Thanks.
I have three keys in total. One is the master key (small, black, plastic key), one is a simple key without remote functions and the third one is the one with full remote functions. The third one stopped at some point operating the remote functions (lock/unlock) but did start the engine. I went through the programming sequence I found on the site and all the remote operations were restored....however, the key stopped starting the engine. The simple spare key didn't work either!!! My only salvation was the master key! And I say salvation, because I reside in East Africa and the BMW dealer here is the lamest ever.
Anyway, the fact that the spare key became inactive as well, makes me think that the mobilizer code changed altogether. Question is...can this be a DIY thing, or do I have to refer to the dealer?!

The small plastic key you're describing is the Emergency key. The vehicle has three types of keys:

• Master Key - This is the large key with the remote functions. Two of these were standard upon delivery of the vehicle.
• Valet Key - This is the gray key. One of these was standard upon delivery of the vehicle.
• Emergency Key - This is the small, black plastic key. One of these was standard upon delivery of the vehicle.

The key I just purchased was the master key and, as delivered from BMW (the only source for new keys), it was capable of starting/operating and manually locking/unlocking the vehicle. It was not programmed for remote locking/unlocking. This had to be performed at the vehicle.

To my knowledge there is no way for the end user to reconfigure the coding of the keys to prevent them from starting/operating the vehicle (other than destroying them). IMO either the key(s) are bad or there's a problem with the vehicle. I highly doubt your programming the master key to remote lock/unlock the vehicle is the cause of the problem.