http://www.lextreme.com/forums/index.php?threads/immobilizer-circuit-wiring-diagram.13856/ This thread might help you understand whats going one. Ecus I have used include 89661-50380 , 89661-50240 or 241 and 89661-50250 or 251 Just a note check the wiring to the ignitors. In the immobilized looms the IGT1 and IGT2 are sometimes swapped to prevent the swapping of a non-immobilized ECU so you will need to change these around. I pop the pins out and swap. Easy as.