Peugeot 406 engine immobiliser fault?

hi,
I have a peugeot 406 autamatic diesal 2002, basically the problem is every time I insert the key into the ignition and start up the car the on board computer says engine immobilizer fault thus the car in result stalls. finally my question is since I bought the car I do not know the current code for the immobilizer and so I would like to know how to completely disable or remove the immobilizer from the car.

thank you and please write back as this is very important.