I have an AD30 which is a coil detector, it bleeps when you insert a key into ignition to indicate a signal has been received but it doesn't work on all systems so can be a bit mis-leading.

Also doesn't the light flashing indicate fault codes dependant on sequence of flash. (not that i know what each flash code means)

Is it possible to place tin foil over the key head to see if this causes a different immobiliser light flashing sequence, so if its a key fault or a reader coil issue I'd hope to think a different fault code be logged.