i have a Musso 3.2 2002 model petrol engine immobiliser is not responding?

when i press the button on the remote doors open but when i try to start the vhecle the starter dos not respond at all, my mechanic told me that the current is reaching the immobiliser but not passing it to engine compartment and fuelpump, please tell me how to overcom this problem or how to disable the immobiliser completely.