key fob not working

[technohippy]

Ive just changed the shell of the key fob in my 02 polo because it was getting a bit ropey looking, the buttons all work fine it unlocks and lock etc but it will not start the car, any idea why? (i say it doesnt start it does it just cuts out after a few seconds)

[legendamongus]

Did you swap the transponder out of the old key shell into the new one? Sounds like the immobiliser is cutting the engine.

[technohippy]

yeah swapped everything only thing that isn't old is the plastic parts of the key ie the main body, the key blade and circuit and battery is still the old one

[technohippy]

i'm an idiot i really am actually stupid....... i thought the transponder was part of the circuit board where as infact it is a small glass bead in the top of the key and so no i had not swapped it over.....
funnily enough i have just swapped it into the new key and what do you know it only works! lol cheers fella even if i did ignore you first time round.

[legendamongus]

no worries mate, glad to hear it's all working now.