Primary key doesnt work, back up does?

[chris blue]

Like many threads on here my immobiliser, with the primary central locking key, doesn't disengage. When key is on ignition position the red light keeps happily flashing away,and engine turns over, but no start

Have replaced key battery, and also used the eBay return kit with new casing etc. No luck.

The back up key with no battery works fine, other than no central locking function. How so? Obviously not an immobiliser issue. Does the back up key have a chip in it? - but if it has there's no battery? How is that key recognised by the immobiliser?

 

[Mike@Rentech]

 

[chris blue]

Thanks. Certainly learnt something there

No battery in the spare key required then

Would still like to repair my primary key. Or find somewhere that can