I have a 2009 honda civic and it was submerged in water a couple weeks ago. I dried everything inside and out and water got inside the gas tank so i drained and cleaned it and replace the gas pump. I can get it ti crank and it will start for 1second then die. I replaced every electrical components that was submerged with water including ECM, fuse boxes and etc.. anybody have an idea on what to check for?

 

Did you program the new ECU for the immobilizer?

 

It was a used ecu

 

New to you. The immobilizer still needs to be programmed.

 

I put the old ECU back and the immobilizer is still flashing (the green key symbol). Does the immobilizer resets if the battery was dead for a couple days?

 

The underdash fuse box (MICU) is also part of the immobilizer. If that was replaced the immobilizer will still need to be programmed.