xsara immobiliser fault

[dei9]

so how does my car start if lexia and that display says there's an immobiliser fault?
lexia said 'transponder authentified not received' from the bsi part, and 'engine immobiliser function. function fault from the injection part.'
but it starts fine at the button? Has it been hacked or bypassed in some way, the little red led light has been bypassed too, it's operated by a switch under the dash now?!
thanks again to all!