Unauthorised key light with new key

[markrw1]

Hi

I'm a newbie but hoping people may help as I've trawled various forums without success.

I lost my main set of keys for my Outback some time ago and have been living dangerously without a spare primarily because of the horrific price of replacements.

Luckily I managed to get a genuine Subaru blank one button key with the proper M Series transponder off eBay. I had the key cut for £10 (good so far) and got the alarm code from Subaru and successfully programmed the new and old key (too easy at this point). The new key now unlocks the car via the button and fits in the ignition and turns to the point where all the dash lights up.

However as soon as the new key enters the ignition the 'unauthorised key' light comes on and stay solid and of course the car won't start. I'm trying to work out if the key is cut slightly wrong and that's why the light comes on or there is something wrong with transponder programming (but then why would the new key successfully unlock the car?).

Has anybody seen this before or got any ideas?

Thanks

[markrw1]

OK - so I've made some further progress.

I've now realised I also need to get the transponder chip programmed as well as the alarm (which works ok) which is why the key light comes on.

Does anyone know if the transponder chips are 'generic' or if they are model specific?

i.e. does 2003 transponder for a Legacy work with an Outback 2006? Are most transponder chips interchangeable for Subarus?

Is the new one button key I have likely to have the same chip as the 2006 original key - is there any way to tell easily?

Its all a bit of a minefield.

Any advice gratefully received!