Remote key not working after battery change

[knight01]

I have a VW Polo 2003 and the battery died on my remote key fob. It was working fine before, then all of a sudden I couldn't lock the car and the little red light on the fob wasn't working.
I replaced the battery in the remote and now the indicator light works on the fob but I can't unlock/lock the car with the remote any more.
I can still use it to manually unlock/lock and run the car. I think the fob has lost sync and needs to be re-synced to the car. I've tried the instructions in the manual about re-syncing the key, but that didn't work.

I've had a look here and as detailed in step 5, my key has lost sync after replacing battery: http://www.autokeysquad.com/replace-vw-volkswagen-key-fob-battery

To carry out the re-sync myself (guide: http://www.autokeysquad.com/volkswagen-car-key-fob-programming-guide) I need another key. Anyone know anywhere in west London area where I can buy and get another key cut? Is there a way to carry out the re-sync with just one key I have at the moment.


Thanks

[vc-10]

The key has a certain number of different codes that it blasts out when you press a button. The car remembers what the last code was, and the codes have a certain order. If the key give out code number 200, then the car expects the next code it receives to be between 201 and 250, say. If it next receives code number 1, because the battery has been changed, then the car won't unlock. I am not sure if the key resets when the battery is changed, but it wouldn't surprise me if it did.

It might be worth speaking to your local VW dealer or Independent about recoding the key.