If the factory remote battery goes flat or the signal is blocked by something (areas of high RF interference like broadcast towers or high-voltage powerlines can do it) then you can still unlock the car with the keys but the immobiliser will still be active, which is what is stopping you from starting the car. You can get around this by either waiting half an hour after unlocking with the keys before attempting to start, or check the glovebox for a little socket which you can push the remote into to disable the immobiliser. Note that I think this only works on the lower-spec models (it does on my parent's '96 CSi) that don't have a full security alarm system, just the basic remote central locking/immobiliser/horn alarm instead of an aftermarket-style chirp w/ glass breakage sensors etc.
Bookmarks