Sorry if this has been covered but I've not found anything covering my exact issue. I got a generic central locking kit fitted to my Fabia a while back and just got the key blade cut. It opens the doors manually but when I start the car the immobiliser key light flashes. The first time the engine cut out but when I tried again it kept running. It starts the car but the light keeps flashing. Any suggestions as to how I can rectify this?

9 minutes ago, Firebhoy said:

It starts the car but the light keeps flashing

Exactly what components make up the ignition key?

This issue throws up beause the immobiliser in the ECU cannot read the key's code so throws up a problem causing non starting and dash warning, the car does start because you have ingnition and a swift cranking turnover straight away and this confuses the ECU that's why it will run, ECU might throw a wobble one day and shut down the system not allowing any thing to work-- fuel pump etc or put the car into limp home mode the only way around this is to  either keep the old internal circuit handy from the old key fob or keep it on a keyring when starting and driving keeping it near the colom where key normally goes to let it start first time as ECU then thinks you have the key code like original and everything is fine, this happened with a friends car that had his ingition lock changed with the key supplied from a breakers yard  for that lock but wasn't a big issue as we changed the key part into the old fob  justworked fine for him in the end but still had to keep the old key handy to use as a mannual lock for doors if needed

I only ever had one key. Just the normal one, not push button. I'm not sure what the key is made up of. Its internals are for the central locking system.

29 minutes ago, Firebhoy said:

I only ever had one key. Just the normal one, not push button. I'm not sure what the key is made up of. Its internals are for the central locking system.

That's the point; where were the electronics, particularly a small glass bead thing, sourced?

I'm not sure what you mean. I still have the original key which starts it with no problems but there's no buttons on it. It wasn't remote central locking. I got a generic central locking kit fitted and got the blade cut on the key. I wasn't sure if it would actually start it but it did. Just the light keeps flashing.

In order to be able to start the car, you'd need an immobiliser decoder chip within the new key like in the original. Otherwise you've now got a key for central locking and one for starting the car.

 

Hope this helps.

As stated you probably have the original key on the ring with the new one so the immobiliser transponder is struggling with range since it isn't in the ignition.

Ah that makes sense. The original key was on the keyring too.