Immobiliser system replacement

[Russie]

Hi all.
If the only operational key I have stops working do I need to replace the the key and instrument cluster as a unit. I understand on the 2002 9n the immobiliser is integrated in the instrumentation cluster.
Does anyone have clarity on any other parts I'd need to replace?
Can I use a second hand set?
What coding is required? Can I use a delphi ds100 for the coding. What info would I need from the old set when looking for the set?
Any other issues I need to keep in mind would be appreciated.

[CarbonChaos]

You should only need to replace the key itself, The same as if someone lost all their keys ,just get new keys coded to the car.

[Russie]

How would one code new keys then. I understood you'd need an operational key to activate additional keys.

[CarbonChaos]

Where did you get that idea ?

[Russie]

From the net as we all do hahaha. A bit of back story here.i recently bought the car with limited history. With the recent error attached I opened the cluster to find another key and connected coil pickup. The key which starts the car has a disconnected coil. I can only assume the previous owner had an issue and swopped the cluster/key or both but didn't bother swopping the ignition. Since I need a new key anyway I'd like to get key/cluster combo to get it working correctly again. Incedently how would I know that my 2002 polo has the immo incorporated in the cluster. I understand (from the net again hahaha) that vw changed over to standalone units at some point. Did I mention I'm new to vw