I have 02 base auto. With 05 k20zi1 amd 6 speed I used the 05 engine harness and dash harness the under the hood fuse box is the 02 I can't get no fire or injection pulse I cant get the main relay to click over I used the 05 ecm and key and immobilizer it will crank I thought the eco was bad so I just bought 05 eco and immobilizer and key didn't help

 

The MICU is also part of the immobilizer. All the pieces need to be programmed to each other to work.