gents just changed the battery on my key fob. my03sti.
the doors open but wont turn off the imobiliser any ideas please

 

Afaik, the immobiliser is a chip in the key, and has nothing to do with the batteries in the fob. has the chip fallen out of the key whilst you have been changing the battery? it looks like a bit of plastic, about 2mm x 2mm x 8mm