I need help with pass code 3 issues

Im repairing a 2003 Buick lesabre attempted theft.
Customer went to the dismantlers and got a ignition switch
complete cylinder lock electrical part of the switch yhe
pass code 3 immobilizer timber and key. I installed it all and
here is were im at. Try to start I hear fuel pump. But nothing
from the ignition switch. Jumped the starter relay and car
turns over. Starts and 4 seconds later dies. Security light on
and stays on the hole time. Tried the relearn or reset and
nothing now the key and immobilizer is out of another car
does that have something to do with it not resetting and if
so will the bypass resistor work. I told my customer he
needs to get the immobilizer and a tumbler and key from
the dealership and that will get him going again and he
showed me these threads so if anyone know the answer to
my question let me know cause it will save this guy a lot of
cash.