Key Not Working

[dvd8n]

I recently found a key for my '11 A3 in the depths of my sofa that I lost a few years ago.

I went to use it this morning; the remote locking worked, the car started put died after a few seconds with (IIRC) an EPC engine warning light.

After a few minute's panic I tried a different key and it was fine.

I presume that it was some sort of immobiliser error.

Any advice?

I did have a new key made while the key was lost - I don't know if that is relevant.

Cheers, David

[dvd8n]

I've been advised that the lost key was probably deregistered from the immobiliser when the new one was made. I'll put it away and get it reregistered if a key ever goes missing again.

David

[Crasher]

Yes, the old key was deleted from the instruments memory, both can be coded in at the same time using ODIS.