My roomster (06)when I bought it came with one key and with the the the wear and tear of the buttons they no longer work but the key in the ignition fine .I then took my key to be copied at timsons In yovil and from then on the new key works once every four times the immobiliser seems to kick in ;is there  anything I could do as I’ve been back to the key shop twice now?

 Is it a 2 or 3 button folding type. It may be worth trying to carefully shake the fob with the blade downward, then try in ignition as immobiliser chip may not be secured correctly inside the fob, and moving to opposite end of fob which may not be close enough to immobiliser ring in ignition.

I have a vague recollection that the receiver coil for the immobiliser transponder in the key is located around the ignition lock barrel on the steering column and has been known to fail (or the connections fail).  I think the coil is a pretty easy replacement so might be worth investigating but after that it could be wiring related:

 

Fabia immobilizer - key signal too low - Skoda Fabia Guides - BRISKODA

On 13/06/2021 at 18:26, Mikewolf said:

My roomster (06)when I bought it came with one key and with the the the wear and tear of the buttons they no longer work but the key in the ignition fine.

Following on from skomaz comment above, does the original key still always work as this would probably negate a receiver coil issue.

On 14/06/2021 at 13:46, KeithCheetham said:

 Is it a 2 or 3 button folding type. It may be worth trying to carefully shake the fob with the blade downward, then try in ignition as immobiliser chip may not be secured correctly inside the fob, and moving to opposite end of fob which may not be close enough to immobiliser ring in ignition.

 It’s a 3 button folding fob , I’ve tried shaking it didn’t work it’s the same 

and for the comments above from skmoz and Keith the old key buttons don’t work even changed the battery just in case but to start the car every time it can start the car no problem  

Sounds like you have an issue with the transponder (the little glass capsule) in the new key then if the old one starts every time.  It may be faulty and need replacing by the key shop.

 

As a temporary 'fix' are the internals the same? - can you transfer the transponder capsule from the old key into the new fob?

 

Edited 15 June, 20214 yr by skomaz

4 hours ago, skomaz said:

Sounds like you have an issue with the transponder (the little glass capsule) in the new key then if the old one starts every time.  It may be faulty and need replacing by the key shop.

 

As a temporary 'fix' are the internals the same? - can you transfer the transponder capsule from the old key into the new fob?

 

It’s a different key you pull it apart from the middle 

24 minutes ago, Mikewolf said:

It’s a different key you pull it apart from the middle 

 

Just put the old key part on the new button part then?...   The transponder capsule is in the part with the key...

 

https://m.youtube.com/watch?v=AtQWM_awulQ

Edited 15 June, 20214 yr by skomaz

I’ll see how it goes as it’s seems to work