New Key Blade not working

[VWKD]

Hi all,

I've done a bit of searching on here but not really sure as to what I need to do to get my new key blade working.

When I bought my car many years ago it came with a normal key with a red bit on it and a keyfob with a broken blade and also a new blade which had been cut to suit. It almost seems the PO was intending to fix the switch-blade fob but never got round to it.

Anyway I managed to get the metal bit that the blade pushes into that was broken on my fob at the weekend from the scrappy so replaced this and put the new blade that came with the car in the keyfob. I have used the keyfob since I bought the car to lock and unloack the car then used the key with the red bit on the start it. When I tried to use the keyfob with new blade in to start the car this morning everything worked sweetly for all of about 10 seconds.. key went in, turned ignition and started car then 10 seconds later imoob light came on and car died.

One thing I am curious about is where the transponder is located? I assume there is one in the keyfob? I've seen an ID48 transponder being mentioned but wondering where it is located?

Is it normal that my car should start for 10 seconds before immobilising? I thought it would just say no from the off.

Any advice on how to get my new blade working would be greatly appreciated I assume the actual blade has nothing to do with it imobilising as I have the original blade I could use but has a load of metal type glue on it which would need removing where PO had tried to fix it back to the spinny round bit on the fob.