[masen54]

Hejsan, fick en extranyckel med när jag köpte bilen, allt fungerar utom att starta bilen, startmotorn snurrar, den gula lampan med
nyckeln på instrumentbrädan tänds inte. Med andra nyckeln fungerar allt som det ska. finns det något jag kan göra själv?
Hyundai i30  2008

[Greyhound]

Translation:
Hello, got an extra key with when I bought the car, everything works except starting the car, the starter motor spins, the yellow light with key on the dashboard does not light up. With the second key, everything works as it should. Is there anything I can do myself? Hyundai i30 2008

[Shambles]

Hi masen54 and 

It sounds to me like your second (spare) key doesn't have the transponder chip installed, which should deactivate the built-in immobiliser, so you cannot start your car.

When I bought my 1st i30 in 2008, it also only came with a spare that didn't start the car. Useless other than to open the doors , so I convinced Hyundai to supply a keyfob that did behave the same as the master fob.

Where do you go from here?  Not sure, other than try to contact Hyundai Sweden to see what they advise.